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Sample records for hydrocracking catalyst prepared

  1. Preparation and Commercial Application of ZHC-01 Hydrocracking Catalyst

    Institute of Scientific and Technical Information of China (English)

    Xu Xuejun; Liu Dongxiang; Wang Haitao; Feng Xiaoping; Wang Jifeng

    2007-01-01

    The ZHC-01 hydrocracking catalyst,characterized by high hydrogenation activity,good selectivity for middle distillates,strong resistance to nitrogen poisoning,was prepared by co-gelling.The catalyst is not only suited to the single-stage hydrocracking process,but also to the first stage of serial hydrocracking process.In parallel with the fully loaded operation of the 1.4 Mt/a hydrocracking unit at the SINOPEC Qilu Petrochemical Company,a pilot test of the ZHC-01 catalyst was also carried out on the hydrocracking unit.The test results indicated that the activity,the yield of major target products and quality of the ZHC-01 catalyst could comply with the design requirements for the hydrocracking unit,and this catalyst could be applied in the hydrocracking unit.The commercial test results showed that the ZHC-01 catalyst,featuring good activity,stability,and flexibility in production,not only could meet the demand for producing environmentally friendly middle distillates,but could also increase the resource of optimized steam cracking feedstock.

  2. Synthesis and characterization of mesoporous hydrocracking catalysts

    Science.gov (United States)

    Munir, D.; Usman, M. R.

    2016-08-01

    Mesoporous catalysts have shown great prospective for catalytic reactions due to their high surface area that aids better distribution of impregnated metal. They have been found to contain more adsorption sites and controlled pore diameter. Hydrocracking, in the presence of mesoporous catalyst is considered more efficient and higher conversion of larger molecules is observed as compared to the cracking reactions in smaller microporous cavities of traditional zeolites. In the present study, a number of silica-alumina based mesoporous catalysts are synthesized in the laboratory. The concentration and type of surfactants and quantities of silica and alumina sources are the variables studied in the preparation of catalyst supports. The supports prepared are well characterized using SEM, EDX, and N2-BET techniques. Finally, the catalysts are tested in a high pressure autoclave reactor to study the activity and selectivity of the catalysts for the hydrocracking of a model mixture of plastics comprising of LDPE, HDPE, PP, and PS.

  3. New hydrocracking catalysts increase throughput, run length

    Energy Technology Data Exchange (ETDEWEB)

    Huizinga, T. [Shell Internationale Petroleum Mij., The Hague (Netherlands); Theunissen, J.M.H. [Rayong Refinery Co. Ltd., Rayong (Thailand); Minderhoud, H.; Veen, R. van [Koninklijke/Shell-Lab., Amsterdam (Netherlands)

    1995-06-26

    An improved, second-stage hydrocracking catalyst has been developed by combining stabilized Y zeolites with amorphous silica alumina cracking components. A commercial application of this catalyst, along with a new, first-stage zeolitic hydrocracking catalyst, resulted in increased unit throughput and cycle length. The paper discusses the hydrocracking process, first-stage catalysts, second-stage catalysts, hydrogenation process, commercial results, and product properties.

  4. In situ sulfiding of Ni-W hydrocracking catalysts : differentiation of different preparation procedures using EXAFS and HRTEM.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, S. D.; Yang, N.; Mickelson, G. E.; Greenlay, N.; Karapetrova, E.; Sinkler, W.; Bare, S. R.; UOP LLC; EXAFS Analysis

    2009-01-01

    The detailed structural characterization of the metal function of two fully formulated Ni-W hydrocracking catalysts was investigated by time resolved in situ X-ray absorption spectroscopy (EXAFS and XANES) at both the Ni K-edge and W L{sub 3}-edge, and by high resolution transmission electron microscopy. These two hydrocracking catalysts (designated as HCA and HCB) contained the same wt% of Ni and W, the same wt% of the other constituents ({gamma}-Al{sub 2}O{sub 3}/silico-aluminate), and were calcined at the same temperature, but were prepared by different methods in order to highlight the sensitivity of the characterization techniques to the structural differences. The morphology of the WS{sub 2} particles in the sulfided catalyst is substantially different between the two catalysts: in the HCA catalyst there are many more particles with multiple WS{sub 2} layers whereas in HCB there are more single layers. The average diameter of the WS{sub 2} plates is similar in both. The catalysts show a difference in the amount of W sulfidation after the 410 C sulfidation treatment in 10% H{sub 2}S/H{sub 2}. The W of HCA catalyst was completely sulfided whereas 16% W of HCB catalyst was unsulfided. Similarly there is a difference in the amount of sulfided Ni: 16% Ni in HCA and 60% Ni in HCB remain unsulfided. In the sulfided form of both catalysts the Ni exists in three different morphologies: oxidized Ni (six-fold coordinate as a nickel aluminate), nanoparticulate Ni{sub 3}S{sub 2}, and Ni decorating the edge sites of the WS{sub 2}. In both the Ni{sub 3}S{sub 2}, and Ni decorating the edge sites of the WS{sub 2}, the Ni is in a tetrahedral coordination with sulfur. In both catalysts the sulfidation of the Ni and W occurs essentially simultaneously over most of the temperature range and the sulfidation of the W proceeds through the same tungsten oxysulfide in both samples. The characterization methodology presented here is a powerful one for elucidating the structural

  5. Effects of Catalyst Preparation on Hydrocarbon Product Distribution in Hydrocracking of the Fischer-Tropsch Product with Low Pt-Loaded Catalysts

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    Toshiaki Hanaoka

    2015-11-01

    Full Text Available For the effective production of hydrocarbon liquid fuel in the hydrocracking of the Fischer-Tropsch (FT product, the catalytic performance of Pt-loaded catalysts with low Pt content was investigated using an autoclave at 250 °C, an initial H2 pressure of 0.5 MPa, and a reaction time of 1 h. A screening study using Pt-loaded catalysts with a Pt content of 0.1 wt. % indicated that zeolite supports were more favorable for jet fuel (carbon numbers 9–15 production than amorphous oxide supports. The small particle size of the supported Pt particles and the high amount of medium acid sites for the supports led to higher performance of the Pt-loaded zeolite catalysts. In the hydrocracking reaction over Pt catalysts using the zeolite support with the high amount of medium acid sites, the yields of the corresponding jet fuel at 0.02 and 0.1 wt. % were almost the same. Pt-loaded catalysts with a Pt content of 0.02 wt. % were prepared using water-in-oil (w/o microemulsions and their particle size was controlled between 1.0 and 2.6 nm. While the yield of the corresponding jet fuel was independent of Pt particle size, smaller Pt particles typically promoted the production of lighter hydrocarbons.

  6. Preparation for Pt-Loaded Zeolite Catalysts Using w/o Microemulsion and Their Hydrocracking Behaviors on Fischer-Tropsch Product

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    Toshiaki Hanaoka

    2015-02-01

    Full Text Available Pt-loaded β-type zeolite catalysts with constant Pt content (0.11 wt.% and similar pore structure were prepared using a water-in-oil (w/o microemulsion. The effect of Pt particle synthesis conditions using microemulsion (a type of Pt complex-forming agents and the molar ratio of complex-forming agent to Pt4+ on loaded Pt particle size was investigated. The Pt particle size of the Pt catalyst using tetraethylammonium chloride (TEAC as a complex-forming agent with the molar TEAC/Pt ratio 10 was the minimum value (3.8 nm, and was much smaller than that (6.7 nm prepared by the impregnation method. The utilization of the complex-forming agent of which hydrophobic groups occupied a small volume and the appropriate complex-forming agent/Pt ratio were favorable for synthesis of small Pt particles. The effect of loaded Pt particle size on the hydrocracking of the Fischer-Tropsch (FT product was investigated using the Pt-loaded zeolite catalysts at 250 °C with an initial H2 pressure of 0.5 MPa, and reaction time of 1 h. The Pt catalyst with a Pt particle size of 4.2 nm prepared using the microemulsion exhibited the maximum corresponding jet fuel yield (30.0%, which was higher than that of the impregnated catalyst.

  7. New catalysts improves heavy feedstock hydro-cracking

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, A.; Huizinga, T.; Esener, A.A.; Maxwell, I.E.; Stork, W. (Koninklijke/Shell Laboratorium, Amsterdam (NL)); van de Meerakker, F.J. (Shell Internationale Petroleum Maatschappij BV, The Hauge (NL)); Sy, O. (Shell Canada Ltd., Oakville, Ontario (CA))

    1991-04-22

    A new zeolite-Y-based second-stage hydrocracking catalyst, designated S-703, has been developed by Shell. Laboratory testing and commercial use show it has significantly improved performance with respect to gas make and middle-distillate selectivity in processing heavy feedstocks when compared to a Shell catalyst, S-753, developed earlier. Further, the new catalyst exhibits enhanced stability. Extensive laboratory testing of the S-703 catalyst has been carried out under single-stage, stacked- bed, two-stage-flow, and series-flow conditions. Commercial experience with the new catalyst has now been obtained in several units. To date, the commercial results have confirmed the laboratory results in terms of the superior, heavy- feedstock processing performance of the new catalyst in all respects. Because the trend toward heavier feedstocks is expected to continue, it is likely that catalysts such as S- 703 will find increasing applications in hydrocrackers in the future.

  8. Pillared clays as catalysts for hydrocracking of heavy liquid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Gyftopoulou, M.E.; Bridgwater, A.V. [Bio-Energy Research Group, Chemical Engineering and Applied Chemistry, School of Engineering and Applied Science, Aston University, Birmingham B4 7ET (United Kingdom); Millan, M.; Dugwell, D.; Kandiyoti, R. [Department of Chemical Engineering and Chemical Technology Imperial College London, London SW7 2BY (United Kingdom); Hriljac, J.A. [School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2005-03-30

    Two sets of pillared clays (PILCs), chromia and tin-oxide-pillared montmorillonites and laponites, were successfully prepared at Aston University using both conventional and microwave-assisted methods and characterised by X-ray diffraction and thermogravimetric analysis. Microwave irradiation enabled the preparation of the PILCs in a fraction of time of the conventional methods. X-ray powder diffraction was not a suitable method for characterizing laponite or pillared laponites due to the lack of first order reflections attributed to the small size of individual particles and the random rather than uniform face-to-face orientation of the clay platelets. Laponite appeared to be more thermally stable than montmorillonite. For pillared montmorillonites, dehydroxylation shifted to a lower temperature compared to the starting materials, whereas for tin-oxide-pillared laponites such a shift did not occur. On the other hand for chromia laponite dehydroxylation took place over a much wider temperature range compared to all other materials. The prepared PILCs were employed as catalysts in the hydrocracking of coal-derived liquids in a conventional microbomb reactor at Imperial College exhibiting high-quality performance and remaining active after 4h utilization regardless of high coke deposition. They actually showed an increase in the total conversion when reused.

  9. Effect of catalyst deactivation on vacuum residue hydrocracking

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    Hoda S. Ahmed

    2013-12-01

    Full Text Available Accelerated deactivation tests of the pre-sulfided Mo–W/SiO2–Al2O3 commercial catalyst were performed using heavy vacuum petroleum feedstock. High reaction temperature employed in the accelerated catalyst aging resulted in large amounts of carbonaceous deposition with high aromaticity, which was found to be the principal deactivation cause. The effect of catalyst deactivation on hydrocracking of vacuum residue was studied. Experiments were carried out in a batch reactor at 60 bar, feed to catalyst ratio 10:1 and temperature 425 °C. The duration time for a cycle-run was 4 h. On increasing the interval duration times from 4 to 20 h (i.e. five cycles, the quality of the hydrocracked products was decreased. In each cycle-run, a fresh feedstock was used with the same sulfide catalyst. The quality of distillate products, such as hydrodesulfurization (HDS was decreased from 61.50% to 39.52%, while asphaltene contents of the total liquid product were increased from 2.7% to 5.2% and their boiling ranges were increased during these duration times due to the successive catalyst deactivation during the 5 cycle-runs, caused by successive adsorption of coke formation.

  10. Development of Hydrocracking Catalyst to Produce High Quality Clean Middle Distillates

    Institute of Scientific and Technical Information of China (English)

    Zhang Xuejun; Zhang Zhihua

    2004-01-01

    A novel hydrocracking Ni-W binary catalyst was tentatively designed and prepared by means of impregnation on mixed supports of modified Y zeolite and amorphous aluminosilicate. The structure and properties of catalyst were extensively characterized by XRD, NH3-TPD, IR and XRF techniques. The performance of catalyst was evaluated by a 100-ml hydrogenation laboratory test unit with two single-stage fixed-bed reactors connected in series. The characterization results showed that the catalyst has a developed and concentrated mesopores distribution, suitable acid sites and acid strength distribution, and uniform and high dispersion of metal sites. Under a high conversion rate of 73.8% with the >350℃ feedstock, a 98. 1m% of C5+yield and 83.5% of middle distillates selectivity were obtained. The yield of middle distillates boiling between 140℃and 370℃ was 68.70m% and its quality could meet the WWFC category Ⅲ specification. It means that this catalyst could be used to produce more high quality clean middle distillates derived from heavy oil hydrocracking. The potential aromatic content of heavy naphtha from 65℃ to 140℃ was 37.5m%. The BMCI value of >370℃ tail oil was 6.6. The heavy naphtha and tail oil are premium feedstocks for catalytic reforming and steam cracker units.

  11. Uses of red mud based catalytic additives in hydrocracking. Pt. 1. Preparation and basic experiments. Einsatz von katalytischen Zusaetzen auf Rotmassebasis beim Hydrocracking. T. 1. Praeparation und Basisversuche

    Energy Technology Data Exchange (ETDEWEB)

    Sourkouni-Argirusi, G.

    1994-10-01

    This report contains two sections. In the first section a limited review is presented and the preparation of the red mud based additives is described. The additives are characterized by composition and their catalytic activity in hydrocracking is investigated in a batch autoclave under an initial hydrogen pressure of 12 MPa at 435 C and 30 min residence time. A quantitative characterization of the products is given. Comparisons between the red mud additives and coke respectively a commercial catalyst are made. (orig.)

  12. Catalytic hydrocracking of Kapuk seed oil (Ceiba pentandra) to produce biofuel using Zn-Mo supported HZSM-5 catalyst

    Science.gov (United States)

    Mirzayanti, Y. W.; Prajitno, D. H.; Roesyadi, A.

    2017-05-01

    In the present paper Kapuk seed oil (KSO) was considered as a potential biofuel for alternative fuel from inedible oil. Catalytic hydrocracking of Kapuk seed oil using Zn-Mo supported on the HZSM-5 catalyst in a slurry pressure batch reactor at various temperature with reactor pressure in range 10-15 bar. The Zn-Mo/HZSM-5 catalyst was prepared by incipient wetness impregnation. The physicochemical properties of the catalyst were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) method. The best catalyst performance on catalytic hydrocracking of KSO using Zn-Mo/HZSM-5 (Si/Al = 25) with loading 2.92%wt for Zn and 7.55%wt for Mo. It displayed the highest hydrocarbon content decarboxylation and/or decarbonylation were 35.51 area% of n-paraffins and the highest content for gasoil-range alkanes was 17.24 area% at 4000C. The liquid product predominant is n-C15, and the second component is n-C17. The catalyst Zn-Mo/HZSM-5 was helpful for the catalytic hydrocracking of KSO for hydrocarbon biofuel production.

  13. ACTIVITY TEST AND REGENERATION OF NiMo/Z CATALYST FOR HYDROCRACKING OF WASTE PLASTIC FRACTION TO GASOLINE FRACTION

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    Rodiansono Rodiansono

    2010-06-01

    Full Text Available Activity test and regeneration of NiMo/active natural zeolite catalyst for hydrocracking of waste plastic fraction of polyprophylene (PP type have been carried out. The catalysts was prepared by loading Mo followed by Ni Metals onto the natural zeolite (Z sample, then calcined at 500oC, oxidized and reduced at 400oC under nitrogen, oxygen and hydrogen stream, respectively. The characterization of catalysts including spesific surface area, average pore radius, and total pore volume were performed by gas sorption analyzer, amount of total acid sites was determined by gas sorption method, and acid site strength was confirmed by IR spectroscopy. The hydrocracking process was carried out in a semi-flow reactor system at 360 oC and catalyst:feed ratio 0.5 under hydrogen stream (150 mL/hour. The feed was vaporized from the pyrolisis reactor into the hydrocracking reactor. A liquid product was collected and analyzed by gas chromatography (GC and gas chromatography-mass spectroscopy (GC-MS. The characterization results showed that spesific surface area, average pore radius, and total pore volume of the Z sample decreased after loading of the Ni and Mo metals. Amount of total acid sites of the NiMo/Z catalyst was higher than that of the Z sample. The activity of NiMo/Z catalyst decreased after several continously runs. Its regeneration produced the NiMo/Z reg catalyst with similar activity and selectivity to the fresh catalyst (NiMo/Z. The activity of catalysts at the optimum condition followed the order of NiMo/Z reg>NiMo/Z>Z (conversion of hydrocarbon C>12 and NiMo/Z reg>NiMo/Z>Z (total yield of gasoline fraction. The selectivity of catalysts for C7-C8 product followed the order of Z>NiMo/Z>NiMo/Z reg. Keywords: activity, polyprophylene, catalyst, gasoline fraction.

  14. Hydrocracking of Cerbera manghas Oil with Co-Ni/HZSM-5 as Double Promoted Catalyst

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    Lenny Marlinda

    2017-05-01

    Full Text Available The effect of various reaction temperature on the hydrocracking of Cerbera manghas oil to produce a paraffin-rich mixture of hydrocarbons with Co-Ni/HZSM-5 as doubled promoted catalyst were studied. The Co-Ni/HZSM-5 catalyst with various metal loading and metal ratio was prepared by incipient wetness impregnation. The catalysts were characterized by XRD, AAS, and N2 adsorption-desorption. Surface area, pore diameter, and pore volume of catalysts decreased with the increasing of metals loading. The hydrocracking process was conducted under hydrogen initial pressure in batch reactor equipped with a mechanical stirrer. The reaction was carried out at a temperature of 300-375 oC for 2 h.  Depending on the experimental condition, the reaction pressure changed between 10 bar and 15 bar.   Several parameters were used to evaluate biofuel produced, including oxygen removal, hydrocarbon composition and gasoline/kerosene/diesel yields. Biofuel was analyzed by Fourier Transform Infrared Spectroscopic (FTIR and gas chromatography-mass spectrometry (GC-MS. The composition of hydrocarbon compounds in liquid products was similar to the compounds in the gasoil sold in unit of Pertamina Gas Stations, namely pentadecane, hexadecane, heptadecane, octadecane, and nonadecane with different amounts for each biofuel produced at different reaction temperatures. However, isoparaffin compounds were not formed at all operating conditions. Pentadecane (n-C15 and heptadecane (n-C17 were the most abundant composition in gasoil when Co-Ni/HZSM-5 catalyst was used. Cerbera Manghas oil can be recommended as the source of non-edible vegetable oil to produce gasoil as an environmentally friendly transportation fuel. Copyright © 2017 BCREC Group. All rights reserved Received: 20th May 2016; Revised: 30th January 2017; Accepted: 10th February 2017 How to Cite: Marlinda, L., Al-Muttaqii, M., Gunardi, I., Roesyadi, A., Prajitno, D.H. (2017. Hydrocracking of Cerbera manghas Oil

  15. NiO-PTA supported on ZIF-8 as a highly effective catalyst for hydrocracking of Jatropha oil.

    Science.gov (United States)

    Liu, Jing; He, Jing; Wang, Luying; Li, Rong; Chen, Pan; Rao, Xin; Deng, Lihong; Rong, Long; Lei, Jiandu

    2016-03-29

    Nickel oxide (NiO) and phosphotungstic acid (PTA) supported on a ZIF-8 (NiO-PTA/ZIF-8) catalyst was first synthesized and it showed high activity and good selectivity for the hydrocracking of Jatropha oil. The catalyst was characterized by SEM, SEM-EDS, TEM, N2 adsorption, FT-IR, XRD and XPS. Compared with the NiO-PTA/Al2O3 catalyst, the selectivity of C15-C18 hydrocarbon increased over 36%, and catalytic efficiency increased 10 times over the NiO-PTA/ZIF-8 catalyst. The prepared NiO-PTA/ZIF-8 catalyst was stable for a reaction time of 104 h and the kinetic behavior was also analyzed. This catalyst was found to bypass the presulfurization process, showing promise as an alternative to sulfided catalysts for green diesel production.

  16. Effect of temperature in hydrocracking of light cycle oil on a noble metal-supported catalyst for fuel production

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, A.; Arandes, J.M.; Castano, P.; Olazar, M.; Bilbao, J. [Universidad del Pais Vasco (UPV-EHU), Departamento de Ingenieria Quimica, Bilbao (Spain); Barona, A. [Universidad del Pais Vasco (UPV-EHU), Escuela de Ingenieria, Departamento de Ingenieria Quimica y Medio Ambiente, Alda, Urkijo s/n, Bilbao (Spain)

    2012-04-15

    The effect of temperature has been studied in hydrocracking of light cycle oil (LCO), byproduct of fluidized catalytic cracking (FCC) units on a bifunctional catalyst (Pt-Pd/HY zeolite). The increase in both temperature and H{sub 2} partial pressure have an important attenuating effect on catalyst deactivation, given that they decrease sulfur equilibrium adsorption and enhance hydrocracking of coke precursors. Therefore, the catalyst maintains significant hydrodesulfurization and hydrocracking activity. As the temperature is increased, hydrocracking conversion and naphtha selectivity increase, although there is no significant dearomatization of the medium distillate fraction in the range of the studied experimental conditions. 400 C is the more suitable temperature for obtaining a high yield of naphtha with a high content of i-paraffins. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Metal-ion pillared clays as hydrocracking catalysts (II): effect of contact time on products from coal extracts and petroleum distillation residues

    Energy Technology Data Exchange (ETDEWEB)

    S.D. Bodman; W.R. McWhinnie; V. Begon; M. Millan; I. Suelves; M.-J. Lazaro; A.A. Herod; R. Kandiyoti [Aston University, Birmingham (United Kingdom). Department of Chemical Engineering and Applied Chemistry

    2003-11-01

    Novel catalysts have been prepared, based on montmorillonite (a natural clay) and laponite (a synthetic clay) pillared with tin, chromium and aluminium pillars as well as layered double hydroxides based on polyoxo-vanadate and -molybdate as previously described. These novel catalysts were compared initially with a standard Ni/Mo catalyst supported on alumina and a dispersed catalyst, Mo(CO){sub 6} in hydrocracking a coal extract for a short contact time of 10 min at 440{sup o}C in a microbomb reactor with tetralin solvent and hydrogen at a pressure of 190 bar. In the present work, the best of the novel catalysts, chromium montmorillonite calcined at 500{sup o}C and tin laponite, have been compared with the supported catalyst and a dispersed catalyst (Mo(CO){sub 6}) in the repeated hydrocracking of fresh coal extract over three sequential periods of 1 h. Also, the chromium montmorillonite calcined at 500{sup o}C has been used in the hydrocracking of primary coal extracts, prepared in the flowing solvent liquefaction rig from Pittsburgh No. 8 and Illinois No. 6 coals, for reaction times of 10 min and 2 h. Further, the chromium montmorillonite calcined at 500{sup o}C and tin laponite, have been compared with the supported catalyst and in the absence of a catalyst, in the hydrocracking of a petroleum distillation residue with 10 min and 2 h reaction times. Results were compared by size exclusion chromatography in NMP solvent and by UV-fluorescence and evaluated by the extent of the shift of the SEC profile to small molecules and by the shift of the synchronous UV-fluorescence profiles to shorter wavelengths. The performances of both catalysts at short, long or repeated reaction times are seen to be better than that of the conventional NiMo catalyst for the hydrocracking of coal-derived materials and a petroleum residue. Trials on a longer time scale are necessary in the next level of evaluation. 37 refs., 14 figs., 1 tab.

  18. Extraction of Nanosized Cobalt Sulfide from Spent Hydrocracking Catalyst

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    Samia A. Kosa

    2013-01-01

    Full Text Available The processes used for the extraction of metals (Co, Mo, and Al from spent hydrotreating catalysts were investigated in this study. A detailed mechanism of the metal extraction process is described. Additionally, a simulation study was performed to understand the sulfidizing mechanism. The suggested separation procedure was effective and achieved an extraction of approximately 80–90%. In addition, the sulfidization mechanism was identified. This sulfidizing process for Co was found to involve an intermediate, the structure of which was proposed. This proposed intermediate was confirmed through simulations. Moreover, the activities of the spent and the regenerated catalyst were examined in the cracking of toluene. The modification of the spent catalyst through the use of different iron oxide loadings improved the catalytic activity.

  19. Anomalous hydrocracking of triglycerides over CoMo-catalyst-influence of reaction intermediates

    Indian Academy of Sciences (India)

    M Anand; M G Sibi; D Verma; A K Sinha

    2014-03-01

    Reaction intermediates have been identified and followed to understand anomalous cracking of jathropha oil triglycerides in the presence of sulphided Co-Mo/Al2O3 catalyst. Undesirable C-C coupling reactions are favoured at temperatures between 320° and 340°C, giving waxy oligomerization products, whereas at temperatures above 340°C, direct hydrocracking of triglycerides to lighter and middle distillates were favoured. To minimize undesirable waxy oligomerization products, higher pressures (>80 bar) and higher H2/feed ratios (>1500) were necessary. Aldol condensation and ketonization reactions between the reaction intermediates are counter-productive as they result in waxy long chain oxygenated products which tend to accumulate on the catalyst surface, choke the reactor and cause rapid catalyst deactivation. Reaction conditions have to be optimized to minimize condensation reaction during this process.

  20. Development of Light Cycle Oil (LCO) Hydrocracking Technology over a Commercial W-Ni Based Catalyst

    Institute of Scientific and Technical Information of China (English)

    Peng Chong; Yang Xuejing; Fang Xiangchen; Huang Xinlu; Cheng Zhenmin; Zeng Ronghui; Guo Rong

    2015-01-01

    Because of its high density and low cetane number, the light cycle oil (LCO) containing heavy aromatics (60%—80%) can hardly be transformed through the conventional hydro-upgrading technology. In this report, a novel LCO hydrocracking technology (FD2G) was proposed for the utilization of LCO to manufacture high value-added products. Through the ingenious combination of hydroprocessing catalyst and the hydrocracking process, the high octane gasoline and the ultra-low sulfur diesel (ULSD) blendstocks were produced simultaneously. The inlfuence of catalyst type, reaction temperature, pressure, respectively, on the research octane number (RON) of produced gasoline was studied in a ifxed bed hydrogenation reactor. It indicated that high reaction temperature and medium pressurewould favor the production of high-octane gasoline through the conversion of bi-aromatic and tri-aromatic hydrocarbons. The typical results of FD2G tech-nology on commercial units showed that it could produce clean diesel with a sulfur content of less than 10 μg/g and clean gasoline with a research octane number (RON) of up to 92. It would be contributed to the achievement of the maximum proift of a reifnery, the FD2G technology could provide a higher economic efifciency than the other diesel quality upgrading technology under the current gasoline and diesel price system.

  1. Conversion of Isoprenoid Oil by Catalytic Cracking and Hydrocracking over Nanoporous Hybrid Catalysts

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    Toshiyuki Kimura

    2012-01-01

    Full Text Available In order to produce petroleum alternatives from biomass, a significant amount of research has been focused on oils from microalgae due to their origin, which would not affect food availability. Nanoporous hybrid catalysts composed of ns Al2O3 and zeolites have been proven to be very useful compared to traditional catalysts in hydrotreating (HT, hydrocracking (HC, and catalytic cracking (CC of large molecules. To evaluate the reaction scheme and products from model isoprenoid compounds of microalgae oil, nanoporous hybrid catalyst technologies (CC: ns Al2O3/H-USY and ns Al2O3/H-GaAlMFI; HC: [Ni-Mo/γ-Al2O3]/ns Al2O3/H-beta were studied. The major product from CC on ns Al2O3/H-USY was highly aromatic gasoline, while the product from HC was half-isoparaffinic/olefinic kerosene. Although more than 50 wt% of the products from HT/CC on the USY catalyst was liquefied petroleum gas due to overcracking, the product from HT/CC on the MFI catalyst was high-octane-number gasoline. Delightfully, the product from HT/HC was kerosene and its average number was 11, with more than 80 wt% being isoparaffinic. As a result, it was demonstrated that hydrotreating may convert isoprenoid oil from microalgae over nanoporous hybrid catalysts into a variety of products.

  2. Conversion of isoprenoid oil by catalytic cracking and hydrocracking over nanoporous hybrid catalysts.

    Science.gov (United States)

    Kimura, Toshiyuki; Liu, Chen; Li, Xiaohong; Maekawa, Takaaki; Asaoka, Sachio

    2012-01-01

    In order to produce petroleum alternatives from biomass, a significant amount of research has been focused on oils from microalgae due to their origin, which would not affect food availability. Nanoporous hybrid catalysts composed of ns Al₂O₃ and zeolites have been proven to be very useful compared to traditional catalysts in hydrotreating (HT), hydrocracking (HC), and catalytic cracking (CC) of large molecules. To evaluate the reaction scheme and products from model isoprenoid compounds of microalgae oil, nanoporous hybrid catalyst technologies (CC: ns Al₂O₃/H-USY and ns Al₂O₃/H-GaAlMFI; HC: [Ni-Mo/γ-Al₂O₃]/ns Al₂O₃/H-beta) were studied. The major product from CC on ns Al₂O₃/H-USY was highly aromatic gasoline, while the product from HC was half-isoparaffinic/olefinic kerosene. Although more than 50 wt% of the products from HT/CC on the USY catalyst was liquefied petroleum gas due to overcracking, the product from HT/CC on the MFI catalyst was high-octane-number gasoline. Delightfully, the product from HT/HC was kerosene and its average number was 11, with more than 80 wt% being isoparaffinic. As a result, it was demonstrated that hydrotreating may convert isoprenoid oil from microalgae over nanoporous hybrid catalysts into a variety of products.

  3. Deactivation and Regeneration of Ni/ZA Catalyst in Hydrocracking of Polypropylene

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    Imam Khabib

    2014-07-01

    Full Text Available The phenomena of catalyst deactivation and the effects of regeneration method on the characteristics and activity of Ni/ZA catalyst after being used in a continuous cracking reaction of polypropylene have been studied. Ni/ZA catalyst was prepared using sonochemical method with total metal intake of 4%. Characteristics and activity of fresh, spent, and regenerated catalyst were evaluated to get a better understanding about the catalyst deactivation. Characteristics which have been observed include catalyst acidity, porosity, crystallinity, and surface morphology. Catalytic activity test of Ni/ZA catalyst on polypropylene cracking reaction at temperature of 500 °C with H2 flow rate of 20 mL/min and catalyst:feed ratio of 1:2 (w/w showed the decrease of some catalyst characteristics such as specific surface area, total pore volume, and acidity due to coke fouling over a five-times continuous experiment. Regeneration of catalyst with oxidation-reduction method has been able to increase the activity and acidity of catalyst up to 7.47% and 38.54%, respectively, compared to those of spent catalyst, while the catalyst surface area and total pore volume decreased up to 32.83% and 26.92%, respectively.

  4. Hydrocracking for oriented conversion of heavy oils. Recent trends for catalyst development

    Energy Technology Data Exchange (ETDEWEB)

    Bertoncini, F.; Bonduelle, A.; Simon, L.J. [IFP Energies nouvelles, Lyon Establishment, Solaize (France). Catalysis and separation Division; Raybaud, P.; Dulot, H. [IFP Energies nouvelles, Lyon Establishment, Solaize (France). Process Desing Modeling Division

    2011-07-01

    As a result of the global economic crisis since the end of 2008, HCK operators have been looking to increase the profitability of the unit by processing heavier feed streams, including sourer VGO. These feeds present the drawbacks of increased H{sub 2} consumption, lower products yields and quality, and reduction in cycle lengths. Along with optimised process parameters, catalysts manufacturers are also investigating novel formulations to deal with challenging feeds. This lecture briefly summarizes the market trends (fuel demand, refinery's product specification) and the driving forces for HCK catalyst development in order to face these new challenges. Finally, this lecture highlights the innovating trends for HCK catalyst's development. Overview of various ideas developed recently in our research laboratory about (i) rational approaches for the atomic scale design of active phases (morphology, preparation, inhibitor effects), (ii) new preparations of transition metal sulphides for maximising the hydrogenating function (precursors, activation,.), (iii) rational approaches of HCK acidic supports for maximizing the selectivity and (iv) better understanding of HCK reactions. These improvements will be discussed in term of improvement of activity and selectivity of HCK catalyst to cope with future market needs. (orig.)

  5. Preparation of Mesoporous Silica-Supported Palladium Catalysts for Biofuel Upgrade

    OpenAIRE

    Ling Fei; Harvind Kumar Reddy; Joshua Hill; Qianglu Lin; Bin Yuan; Yun Xu; Peter Dailey; Shuguang Deng; Hongmei Luo

    2012-01-01

    We report the preparation of two hydrocracking catalysts Pd/CoMoO4/silica and Pd/CNTs/CoMoO4/silica (CNTs, carbon nanotubes). The structure, morphologies, composition, and thermal stability of catalysts were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), and thermogravimetric analysis (TGA). The catalyst activity was measured in a Parr reactor with camelina fatty acid methyl est...

  6. Hydrocracking of Jatropha Oil over non-sulfided PTA-NiMo/ZSM-5 Catalyst

    Science.gov (United States)

    Yang, Xiaosong; Liu, Jing; Fan, Kai; Rong, Long

    2017-01-01

    The PTA-NiMo/ZSM-5 catalyst impregnated with phosphotungstic acid (PTA) was designed for the transformation of Jatropha oil into benzene, toluene, and xylenes (BTX) aromatics. The produced catalyst was characterized by N2 adsorption-desorption, powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), and the temperature-programmed desorption of ammonia (NH3-TPD). The catalytic performance was evaluated by gas chromatography (GC). The liquid products were 70 wt% of the feed oil, and the majority of the liquid products were BTX. The aromatization activity of the catalyst was improved by the addition of PTA and the hierarchical process. The favorable PTA amount was 20 wt% and the yield of BTX was 59 wt% at 380 °C, 3 MPa, H2/oil (v/v) = 1000 and LHSV = 1 h-1 over the PTA20-NiMo/HZ0.5 catalyst (PTA 20 wt%) without sulfurization.

  7. Study on molecular modelling of the selectivity of catalysts for heavy petroleum fractions hydrocracking; Etude sur molecule modele des parametres regissant la selectivite des catalyseurs d'hydrocraquage des charges lourdes

    Energy Technology Data Exchange (ETDEWEB)

    Leite, L.

    2000-10-19

    Hydrocracking is a catalytic petroleum refining process that is commonly applied to upgrade the heavier fractions obtained from the distillation of crude oils. Nowadays the European demand for good quality middle distillates (kerosene and gas-oil) is high and one important goal for the refining is to transform selectively feedstocks into middle distillates. To understand how this transformation occurs, studies on model compounds have been investigated. Numerous studies have been devoted to paraffin hydrocracking. However theses molecules do not fully represent heavy petroleum fraction. Taking into account that the trend in the future will be to treat heavier feedstocks containing a large quantity of PNA (Polynuclear Aromatic hydrocarbons), the understanding of their transformation under hydrocracking conditions is a key point. In this study, we studied hydrocracking of phenanthrene over platinum on acid solids catalysts. Our main aim was to compare hydrocracking catalysts in term of catalytic activity and selectivity toward primary products thanks to our model reaction and to correlate these catalytic performances with acid solid properties and especially to rationalize the effects due to the acidity and the porosity of the acid solids. Catalytic experiments emphasised an effect of the porous structure on the selectivities. The acidity of the catalysts seemed to impose the catalytic activity but did not permit to explain the selectivities. This 'effect of the structure' has been clarified with the simulation of intermediate products adsorption and diffusion in the studied structures thanks to a molecular modelling study. Indeed, the selectivities obtained during phenanthrene hydrocracking have been linked up with the intermediate products adsorption energies in the structures. The results of this study permit to propose that the key-step for selectivities determination is the physical desorption of the primary products. (author)

  8. High-quality bio-oil from one-pot catalytic hydrocracking of kraft lignin over supported noble metal catalysts in isopropanol system.

    Science.gov (United States)

    Yang, Jing; Zhao, Liang; Liu, Shaotong; Wang, Yuanyuan; Dai, Liyi

    2016-07-01

    Catalytic hydrocracking of kraft lignin was carried out in isopropanol system and an orthogonal array design (OAD) was employed to optimize the experimental conditions. GC-MS/FID, elemental analysis, GPC and (1)H-(13)C HSQC NMR were carried out for entire investigation of the liquid products. The results indicated that the hydrocracking process was thermally controlled and catalysts showed significant influences on the product distributions. Comparing with Pd/C, Pt/C and Ru/C, Rh/C inhibited the self-condensation of isopropanol and reduced the formation of oxygenic-chain compounds. The excellent catalytic activity for phenols conversion was obtained over Rh/C. The routes of oxygenic-chain compounds formation and phenol conversion were proposed in detail. The least oxygenic-chain compounds formation, the highest phenols conversion (93.4%), the lowest O/C ratio (0.094) and the highest HHV (37.969MJ/kg) provided the possibility of the high quality bio-oil obtained over Rh/C in isopropanol medium.

  9. Synthesis of Faujasite from Fly Ash and its Applications for Hydrocracking of Petroleum Distillates

    OpenAIRE

    Sutarno Sutarno; Yateman Arryanto

    2007-01-01

    The synthesis of faujasite from fly ash and its application for hydrocracking catalyst of heavy petroleum distillates have been performed. Faujasite was synthesized from fly ash by hydrothermal reaction in alkaline solution via combination of reflux pretreatment of fly ash with HCl and fusion with NaOH. The preparation of nickel containing catalysts by ion exchange method under similar initial concentration of nickel resulted higher amount of nickel loaded on faujasite than those on ze...

  10. Hydroisomerization and hydrocracking of hydrocracker bottom for producing lube base oil

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Hao; Shen, Ben-xian [State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237 (China); Wang, Qiang [Sinopec Maoming Petrochemical Co. Ltd, Maoming, Guangdong 525011 (China)

    2009-04-15

    The reaction of hydrocracker bottom hydroisomerization and hydrocracking was studied in a fixed bed micro reactor over a commercial catalyst. Normal hexadecane was used as model compound to judge the reactivity of the catalyst. Then, hydrocracker bottom was investigated, and the reaction liquid products were collected and distillated into light and heavy fractions for detailed investigation. Hydrocarbon types and carbon number distribution of them were fully analyzed. Results indicate that normal paraffins are easy to be hydroconverted into isoparaffins or small molecules. Isoparaffins and monocycloalkanes have similar hydroisomerization and hydrocracking properties. Fused cycloalkanes are hard to be cracked. Hydroconversion of normal paraffins, isoparaffins and monocycloalkanes dominate the reason of the drop of VI and pour point. (author)

  11. Application of Hydrocracking Process for Upgrading Tail Oil Quality in 1.0 Mt/a Hydrocracker Unit at SINOPEC Yangzi Petrochemical Company

    Institute of Scientific and Technical Information of China (English)

    Zhang Haichun; Dong Jianwei

    2009-01-01

    This article focuses on the hydrocracking technology for upgrading the quality of tail oil and the first commercial application of the RN-32V/RHC-1 catalysts in the 1.0 Mt/a hydrocracker at the Yangzi Petrochemical Company, which was started up successfully in September 2008. One month after start-up of the hydrocracking unit, an evaluation opera-tion has been conducted for assessing the catalysts performance. The technical calibration results showed that the RN-32V/RHC-1 catalysts had high activity, and the product yield distribution was reasonable. The hydrocracker can provide abundant feedstocks for the downstream aromatic production unit and ethylene production unit.

  12. Preparation of Mesoporous Silica-Supported Palladium Catalysts for Biofuel Upgrade

    Directory of Open Access Journals (Sweden)

    Ling Fei

    2012-01-01

    Full Text Available We report the preparation of two hydrocracking catalysts Pd/CoMoO4/silica and Pd/CNTs/CoMoO4/silica (CNTs, carbon nanotubes. The structure, morphologies, composition, and thermal stability of catalysts were studied by X-ray diffraction (XRD, scanning electron microscopy (SEM, Raman spectroscopy, transmission electron microscopy (TEM, energy-dispersive X-ray (EDX, and thermogravimetric analysis (TGA. The catalyst activity was measured in a Parr reactor with camelina fatty acid methyl esters (FAMEs as the feed. The analysis shows that the palladium nanoparticles have been incorporated onto mesoporous silica in Pd/CoMoO4/silica or on the CNTs surface in Pd/CNTs/CoMoO4/silica catalysts. The different combinations of metals and supports have selective control cracking on heavy hydrocarbons.

  13. Study on Hydrocracking of VGO Derived from Kazakhstan-Russian Mixed Crude

    Institute of Scientific and Technical Information of China (English)

    Dong Yuancheng; Duan Yongsheng; Zou Yhiying; Wang Jian; Ye Xingbin; Yang Jianxin

    2006-01-01

    This article investigates the influence of the property of VGO derived trom the Kazakhstan-Russian mixed crude on the hydrocracking catalyst. The influence of reaction temperature, reaction pressure, space velocity and hydrogen/oil ratio on the distribution and quality of products was analyzed with the optimal process regime determined, when the VGO was hydrocracked in the presence of the FC-16 catalyst.

  14. Rhenium Nanochemistry for Catalyst Preparation

    Directory of Open Access Journals (Sweden)

    Vadim G. Kessler

    2012-08-01

    Full Text Available The review presents synthetic approaches to modern rhenium-based catalysts. Creation of an active center is considered as a process of obtaining a nanoparticle or a molecule, immobilized within a matrix of the substrate. Selective chemical routes to preparation of particles of rhenium alloys, rhenium oxides and the molecules of alkyltrioxorhenium, and their insertion into porous structure of zeolites, ordered mesoporous MCM matrices, anodic mesoporous alumina, and porous transition metal oxides are considered. Structure-property relationships are traced for these catalysts in relation to such processes as alkylation and isomerization, olefin metathesis, selective oxidation of olefins, methanol to formaldehyde conversion, etc.

  15. Hydrocracking of vacuum gas oil-vegetable oil mixtures for biofuels production.

    Science.gov (United States)

    Bezergianni, Stella; Kalogianni, Aggeliki; Vasalos, Iacovos A

    2009-06-01

    Hydrocracking of vacuum gas oil (VGO)--vegetable oil mixtures is a prominent process for the production of biofuels. In this work both pre-hydrotreated and non-hydrotreated VGO are assessed whether they are suitable fossil components in a VGO-vegetable oil mixture as feed-stocks to a hydrocracking process. This assessment indicates the necessity of a VGO pre-hydrotreated step prior to hydrocracking the VGO-vegetable oil mixture. Moreover, the comparison of two different mixing ratios suggests that higher vegetable oil content favors hydrocracking product yields and qualities. Three commercial catalysts of different activity are utilized in order to identify a range of products that can be produced via a hydrocracking route. Finally, the effect of temperature on hydrocracking VGO-vegetable oil mixtures is studied in terms of conversion and selectivity to diesel, jet/kerosene and naphtha.

  16. Synthesis of Faujasite from Fly Ash and its Applications for Hydrocracking of Petroleum Distillates

    Directory of Open Access Journals (Sweden)

    Sutarno Sutarno

    2007-10-01

    Full Text Available The synthesis of faujasite from fly ash and its application for hydrocracking catalyst of heavy petroleum distillates have been performed. Faujasite was synthesized from fly ash by hydrothermal reaction in alkaline solution via combination of reflux pretreatment of fly ash with HCl and fusion with NaOH. The preparation of nickel containing catalysts by ion exchange method under similar initial concentration of nickel resulted higher amount of nickel loaded on faujasite than those on zeolite Y, however, the structural damage of faujasite was higher than those of zeolite Y. In the hydrocracking of heavy petroleum distillates over Ni-faujasite and Ni-zeolite Y catalysts, the conversion of heavy gas oil fraction was the most pronounced. The selectivity toward hydrocarbons in the range of gasoline and kerosene obtained over Ni-faujasite catalyst was lower compared to those of Ni-zeolite Y reference catalyst. © 2007 BCREC UNDIP. All rights reserved.[Presented at Symposium and Congress of MKICS 2007, 18-19 April 2007, Semarang, Indonesia][How to Cite: S. Sutarno, Y. Arryanto. (2007. Synthesis of Faujasite from Fly Ash and its Applications for Hydrocracking of Petroleum Distillates. Bulletin of Chemical Reaction Engineering and Catalysis, 2 (2-3: 45-51.  doi:10.9767/bcrec.2.2-3.9.45-51][How to Link/DOI: http://dx.doi.org/10.9767/bcrec.2.2-3.9.45-51 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/9][Cited by: Scopus 1 | ScienceAsia |

  17. CATALYTIC HYDROCRACKING OF WASTE LUBRICANT OIL INTO LIQUID FUEL FRACTION USING ZnO, Nb2O5, ACTIVATED NATURAL ZEOLITE AND THEIR MODIFICATION

    Directory of Open Access Journals (Sweden)

    Wega Trisunaryanti

    2010-06-01

    Full Text Available Catalytic hydrocracking of waste lubricant oil into liquid fuel fraction using ZnO, Nb2O5, activated natural zeolite (ZAAH and their modification has been investigated. The zeolite was produced in Wonosari, Yogyakarta. Activation of the zeolite was carried out by refluxing with HCl 3M for 30 min, produced the activated natural zeolite (ZAAH. The ZnO/ZAAH catalyst was prepared by impregnation of Zn onto the ZAAH by ion exchange method using salt precursor of Zn(NO32.4H2O. The Nb2O5/ZAAH catalyst was prepared by mixing the ZAAH sample with Nb2O5 and oxalic acid solution until the paste was formed. The impregnation of Zn onto Nb2O5/ZAAH was carried out using the same method to that of the ZnO/ZAAH catalyst resulted ZnO/Nb2O5-ZAAH catalyst. Characterization of catalyst includes determination of Zn metal by Atomic Absorption Spectroscopy (AAS, acidity by gravimetric method and catalyst porosity by Surface Area Analyzer (NOVA-1000. Catalytic hydrocracking was carried out in a semi-batch reactor system using ZnO, ZAAH, ZnO/ZAAH and ZnO/Nb2O5-ZAAH catalysts at 450 oC under the H2 flow rate of 15 mL/min. and the ratio of catalyst/feed = 1/5. The composition of liquid products was analyzed by Gas Chromatograpy (GC.The results showed that impregnation of ZnO and/or Nb2O5 on the ZAAH increased the acidity and specific surface area of catalyst. The products of the hydrocracking process were liquid, coke and gas. Conversion of liquid products was increased by the increase of catalyst acidity. The highest liquid product was produced by ZnO/Nb2O5-ZAAH catalyst, 52.97 wt-%, consist of gasoline, 38.87 wt-% and diesel, 14.10 wt-%.   Keywords: hydrocracking, waste lubricant oil, liquid fuel fraction

  18. Effect of NiW Modified HZSM-5 and HY Zeolites on Hydrocracking Conversion of Crude Palm Oil to Liquid Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Maliwan Subsadsana

    2016-05-01

    Full Text Available The catalytic conversion of crude palm oil over HZSM-5 and HY zeolites modified with NiW as catalysts in the hydrocracking process was investigated. These zeolites supported by NiW catalysts were prepared employing the impregnation technique. NiW was added to the zeolites in order to induce bi-functional properties (both acid and metal sites in the catalysts. Subsequently, the catalysts were characterized by X-ray diffraction spectrometry (XRD, scanning electron microscope (SEM, transmission electron microscope (TEM, ammonia temperature programmed desorption (NH3-TPD andnitrogen adsorption-desorption isotherms analysis. The catalytic activity of prepared catalysts was evaluated through the conversion of crude palm oil to biofuels. These results indicate that the incorporation of NiW over HZSM-5 and HY zeolites improves the conversion efficiency and enhances the yield of biofuel (gasoline, kerosene, and diesel, possibly due to NiW promote of hydrogenation and dehydrogenation reaction.

  19. Resin catalysts and method of preparation

    Science.gov (United States)

    Smith, L.A. Jr.

    1986-12-16

    Heat stabilized catalyst compositions are prepared from nuclear sulfonic acid, for example, macroporous crosslinked polyvinyl aromatic compounds containing sulfonic acid groups are neutralized with a metal of Al, Fe, Zn, Cu, Ni, ions or mixtures and alkali, alkaline earth metals or ammonium ions by contacting the resin containing the sulfonic acid with aqueous solutions of the metals salts and alkali, alkaline earth metal or ammonium salts. The catalysts have at least 50% of the sulfonic acid groups neutralized with metal ions and the balance of the sulfonic acid groups neutralized with alkali, alkaline earth ions or ammonium ions.

  20. High pressure hydrocracking of vacuum gas oil to middle distillates

    Science.gov (United States)

    Lahiri, C. R.; Biswas, Dipa

    1986-05-01

    Hydrocracking of heavier petroleum fractions into lighter ones is of increasing importance today to meet the huge demand, particularly for gasoline and middle distillates. Much work on hydrocracking of a gas oil range feed stock to mainly gasoline using modified zeolite catalyst-base exchanged with metals (namely Ni, Pd, Mo, etc.) has been reported. In India, however, present demand is for a maximum amount of middle distillate. The present investigation was therefore aimed to maximize the yield of middle distillate (140-270°C boiling range) by hydrocracking a vacuum gas oil (365-450°C boiling range) fraction from an Indian Refinery at high hydrogen pressure and temperature. A zeolite catalyst-base exchanged with 4.5% Ni was chosen for the reaction. A high pressure batch reactor with a rocking arrangement was used for the study. No pretreatment of the feed stock for sulphur removal applied as the total sulphur in the feed was less than 2%. The process variables studied for the maximum yield of the middle distillate were temperature 300-450°C, pressure 100-200 bar and residence period 1-3 h at the feed to catalyst ratio of 9.3 (wt/wt). The optimum conditions for the maximum yield of 36% middle distillate of the product were: temperature 400°C, pressure 34.5 bar (initially) and residence period 2 h. A carbon balance of 90-92% was found for each run.

  1. Synthesis of supported and unsupported NiMo carbides and their properties for the catalytic hydrocracking of n-octane

    Energy Technology Data Exchange (ETDEWEB)

    Torre, A I Reyes de la [Instituto Tecnologico de Ciudad Madero, Division de Estudios de Posgrado e Investigacion, Juventino Rosas y Jesus Urueta S/N, Colonia Los Mangos, CP 89440, Ciudad Madero, Tamaulipas (Mexico); Banda, J A Melo [Instituto Tecnologico de Ciudad Madero, Division de Estudios de Posgrado e Investigacion, Juventino Rosas y Jesus Urueta S/N, Colonia Los Mangos, CP 89440, Ciudad Madero, Tamaulipas (Mexico); Alamilla, R GarcIa [Instituto Tecnologico de Ciudad Madero, Division de Estudios de Posgrado e Investigacion, Juventino Rosas y Jesus Urueta S/N, Colonia Los Mangos, CP 89440, Ciudad Madero, Tamaulipas (Mexico); Sandoval Robles, G [Instituto Tecnologico de Ciudad Madero, Division de Estudios de Posgrado e Investigacion, Juventino Rosas y Jesus Urueta S/N, Colonia Los Mangos, CP 89440, Ciudad Madero, Tamaulipas (Mexico); Rojas, E Terres [Instituto Mexicano del Petroleo, Molecular Engineering Program, 152 Eje Central L Cardenas, 07730 San Bartolo Atepehuacan, Delegacion Gustavo A Madero, Mexico DF (Mexico); Lopez Ortega, A [Instituto Mexicano del Petroleo, Molecular Engineering Program, 152 Eje Central L Cardenas, 07730 San Bartolo Atepehuacan, Delegacion Gustavo A Madero, Mexico DF (Mexico); Dominguez, J M [Instituto Mexicano del Petroleo, Molecular Engineering Program, 152 Eje Central L Cardenas, 07730 San Bartolo Atepehuacan, Delegacion Gustavo A Madero, Mexico DF (Mexico)

    2004-06-09

    Unsupported and {gamma}-Al{sub 2}O{sub 3}-, MCM-41-supported (Ni, Mo) carbides were prepared and modified by 'in situ' polymer (PAN: polyacrylonitrile) pyrolysis. The supported catalysts were impregnated with Ni and Mo metals, i.e. 2.8 atom Mo/nm{sup 2}, whose atomic ratio was Ni/Ni+Mo = 0.5. X-ray diffraction (XRD) showed single NiC, MoC phases in all cases, with relatively low surface areas, as verified by N{sub 2} adsorption (BET). The catalytic behaviour of the supported (Ni, Mo)C phases for n-C{sub 8} hydrocracking depended on the support type. (Ni, Mo)C/MCM41-PAN-P (P = pyrolyzed) showed a total conversion of 40% while it was only 15% on Ni,MoC/{gamma}-Al{sub 2}O{sub 3}. The most active catalysts were (Ni, Mo)C unsupported catalysts, i.e., 90% total conversion. In all cases the hydrocracking selectivity favoured lighter hydrocarbons (C{sub 1}-C{sub 4})

  2. An improved method of preparation of nanoparticular metal oxide catalysts

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention concerns an improved method of preparation of nanoparticular vanadium oxide/anatase titania catalysts having a narrow particle size distribution. In particular, the invention concerns preparation of nanoparticular vanadium oxide/anatase titania catalyst precursors comprising...... combustible crystallization seeds upon which the catalyst metal oxide is coprecipitated with the carrier metal oxide, which crystallization seeds are removed by combustion in a final calcining step.......The present invention concerns an improved method of preparation of nanoparticular vanadium oxide/anatase titania catalysts having a narrow particle size distribution. In particular, the invention concerns preparation of nanoparticular vanadium oxide/anatase titania catalyst precursors comprising...

  3. Preparative characteristics of hydrophobic polymer catalyst for the tritium removal

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hee Suk; Choi, H. J.; Lee, H. S.; Ahn, D. H.; Kim, K. R.; Paek, S. W.; Kim, J. G.; Chung, H. S

    2001-05-01

    The optimum method for the fabrication of hydrophobic catalyst was selected and the apparatuses for the preparation of catalyst support with high yield was developed for the large scale production. Also, we summarized the method of improving the physical property of the catalyst support, the loading characteristics of Pt metal as a catalyst, and the characteristics of the apparatus for the fabrication of the catalysts on a large scale.

  4. Regeneration of Hydrotreating and FCC Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    CM Wai; JG Frye; JL Fulton; LE Bowman; LJ Silva; MA Gerber

    1999-09-30

    -earth exchanged Y zeolite in a silica-alumina matrix. X-ray fluorescence analyses showed that the rare earths used in preparing the catalysts were a mixture of lanthanum and cerium. Antimony found in the spent catalyst was added during operation of the FCC unit as a way to suppress the adverse effects of deposited nickel. The fresh HDS samples consisted of sulfided nickel and molybdenum on an alumina support. The spent catalyst showed nearly 10% vanadium on the catalyst and a modest increase in nickel and sulfur on the catalyst as a result of operations. Hydrocracking catalysts were not available for this study.

  5. Studies on the hydrocracking of deashed oil (5)

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Takao; Masuyama, Tetsuo; Kageyama, Yoichi; Kawai, Satoshi (Asia Oil Co., Ltd., Tokyo, Japan; Mitsubishi Chemical Industries Ltd., Tokyo (Japan); Nippon Brown Coal Liquefaction Ltd., Tokyo (Japan))

    1987-10-01

    Preliminary sulfiding method of catalyst and the influences DAO (Delimed Ash Oil) exercises on decomposition response activity in the technical development of two-stage hydroliquefaction of Australian brown coal were studied by the TPS (Temperature Programmed Sulfiding) analysis and the X-ray Photoelectron Spectrum (XPS) analysis. The catalyst was Ca-Ni-Mo/Al{sub 2}O{sub 3}. As the gramma value becomes greater, the DAO invert ratio is increased and the coak formation is reduced. The additive Ca fixed to Mo atom by high-dispersion due to the CaMoO{sub 4} structure exists as CaS near the MOS{sub 2} polymer structure by sulfiding. The catalyst which went through structural rearrangement by sulfiding in this way forms a hydrocracking active spot by MoS{sub 2} (Mo-Ni-S structure). Ca interacts with a part of the solid acid spot which is formed accompanied with the formation of a hydrocracking active spot. As a result, the adsorption of the organic nitrogen compound and the polynuclear aromatic compound which are the preceding body of coak is weakened, and the lowering of the initial catalyst activity is suppressed. 4 refs., 4 figs.

  6. Supported cobalt catalysts - preparation, characterization and reaction studies

    OpenAIRE

    Backman, Leif

    2009-01-01

    The aim of this work was to understand on the effect of thermal treatments, precursor and support on the interaction between the support and cobalt species, and further how the interaction affects the reducibility and dispersion of the catalyst. Silica and alumina supported cobalt catalysts were prepared, characterised and tested for catalytic activity. The catalysts were prepared by gas phase deposition techniques from cobalt acetylacetonate and cobalt carbonyl and by incipient wetness impre...

  7. Hydrocracking of ethyl laurate on bifunctional micro-/mesoporous composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Adam, M.; Busse, O.; Reschetilowski, W. [Technische Univ. Dresden (Germany). Inst. for Industrial Chemistry

    2011-07-01

    Hydrocracking of ethyl laurate (dodecanoic acid ethyl ester) as a representative model compound of vegetable oil has been investigated in a fixed bed reactor under integral conditions. A synthesized micro-/mesoporous composite support material Al-MCM-41/ZSM-5 modified by different metal loadings (NiMo, NiW, PtNiW) was used as catalyst system. It could be demonstrated that the metal loading and reducibility influence product selectivity as well as deactivation behavior of catalyst samples. (orig.)

  8. Influence of metal loading on hydrocracking of rapeseed oil using bifunctional micro-/mesoporous composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Gille, T.; Busse, O.; Reschetilowski, W. [Technische Univ. Dresden (Germany). Inst. of Industrial Chemistry

    2013-11-01

    Hydrocracking of rapeseed oil has been investigated in a fixed bed reactor under integral conditions. A synthesized micro-/mesoporous composite material Al-MCM-41/ZSM-5 modified by different metal loadings (NiMo, PtNiMo, Pt) was used as catalyst system. It could be demonstrated that the support material and their metal loading influence the product selectivity as well as the deactivation tendencies of the catalyst sample. (orig.)

  9. Preparation of Cs-Rb-V series sulphuric acid catalyst

    Institute of Scientific and Technical Information of China (English)

    陈振兴; 杨刚; 叶华

    2001-01-01

    Cs-Rb-V series low temperature sulphuric acid catalyst was prepared for the first time by using carbonized mother liquor containing alkali-metal salts. The results show that the conversion of SO2 on catalyst prepared directly with carbonized mother liquor could reach to 24.8% at 410℃. If n(Na)/n(V) was adjusted properly, the conversion of SO2 could be increased to 35.6% at 410℃. Refined carbonized mother liquor could make the catalytic activity even higher at low temperature, the conversion of SO2 could be increased to 36.65% at 410℃. The catalyst was examined with differential thermal analysis. It was found that both endothermic peaks and exothermic peaks of catalyst shifted forward obviously and the catalyst possessed higher activity at low temperature.

  10. Properties of the FCC Catalyst Additive Prepared from Guizhou Kaoline

    Directory of Open Access Journals (Sweden)

    Xianlun Xu

    2006-09-01

    Full Text Available The properties of a FCC catalyst additive prepared from Guizhou kaoline were extensively investigated. The samples were characterized by N2 adsorption, X-ray diffraction, IR spectrometry, and scanning electron microscope (SEM. The results showed that the crystallinity of NaY zeolite synthesized from this kaoline was 25% and the silica alumina ratio was rk/s ˇ m = 5.05. The catalyst additive prepared from above crystallization product exhibited excellent performance of nickel and vanadium passivation, offered 21% lower coke versus base catalyst, while maintaining high bottoms upgrading selectivity.

  11. Preparation of biodiesel from soybean oil by using heterogeneous catalyst

    Directory of Open Access Journals (Sweden)

    Kaniz Ferdous, M. Rakib Uddin, Maksudur R. Khan, M. A. Islam

    2013-01-01

    Full Text Available The predicted shortage of fossil fuels and related environmental concerns has recently attracted significant attention to search alternative fuel. Biodiesel is one of the alternatives to fossil fuel. Now-a-days, most biodiesel is produced by the transesterification of oils using methanol and a homogeneous base catalyst. The use of homogeneous catalysts is normally limited to batch mode processing followed by a catalyst separation step. The immiscible glycerol phase, which accumulates during the course of the reaction, solubilizes the homogeneous base catalyst and therefore, withdraws from the reaction medium. Moreover, other difficulties of using homogeneous base catalysts relate to their sensitivity to free fatty acid (FFA and water and resulting saponification phenomenon. High energy consumption and costly separation of the catalyst from the reaction mixture have inspired the use of heterogeneous catalyst. The use of heterogeneous catalysts does not lead to the formation of soaps through neutralization of FFA and saponification of oil. In the present paper, biodiesel was prepared from crude (soybean oil by transesterification reaction using heterogeneous base catalyst name calcium oxide (CaO. Various reaction parameters were optimized and the biodiesel properties were evaluated.

  12. Preparation of biodiesel from soybean oil by using heterogeneous catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Ferdous, Kaniz; Rakib Uddin, M.; Islam, M.A. [Department of Chemical Engineering and Polymer Science, Shah Jalal University of Science and Technology, Sylhet 3114 (Bangladesh); Khan, Maksudur R. [Department of Chemical Engineering and Polymer Science, Shah Jalal University of Science and Technology, Sylhet 3114 (Bangladesh); Faculty of Chemical and Natural Resources Engineering, University Malaysia Pahang, 26300 Gambang, Kuantan, Pahang (Malaysia)

    2013-07-01

    The predicted shortage of fossil fuels and related environmental concerns has recently attracted significant attention to search alternative fuel. Biodiesel is one of the alternatives to fossil fuel. Now-a-days, most biodiesel is produced by the transesterification of oils using methanol and a homogeneous base catalyst. The use of homogeneous catalysts is normally limited to batch mode processing followed by a catalyst separation step. The immiscible glycerol phase, which accumulates during the course of the reaction, solubilizes the homogeneous base catalyst and therefore, withdraws from the reaction medium. Moreover, other difficulties of using homogeneous base catalysts relate to their sensitivity to free fatty acid (FFA) and water and resulting saponification phenomenon. High energy consumption and costly separation of the catalyst from the reaction mixture have inspired the use of heterogeneous catalyst. The use of heterogeneous catalysts does not lead to the formation of soaps through neutralization of FFA and saponification of oil. In the present paper, biodiesel was prepared from crude (soybean) oil by transesterification reaction using heterogeneous base catalyst name calcium oxide (CaO). Various reaction parameters were optimized and the biodiesel properties were evaluated.

  13. Preparation and evaluation of sulfided NiMo/γ-Al2O3 hydrotreating catalysts

    OpenAIRE

    KAMYAB, ALI

    2016-01-01

      Four nickel-molybdenum catalysts were synthesized on gamma alumina with higher surface area and on NiMo catalyst was prepared using gamma alumina with lower surface area. Catalysts with higher-surface-area support were prepared by co-impregnation, sequential impregnation and adding phosphorous. Theses catalysts were calcined at 500  ͦC. Effect of higher calcination temperature was investigated by preparation of one catalyst calcined at 700 ͦC. Catalysts were thoroughly characterized via fou...

  14. Preparation and Characterization of Sugar Based Catalyst on Various Supports

    Directory of Open Access Journals (Sweden)

    Jidon Adrian Janaun

    2017-04-01

    Full Text Available A novel structured carbon-based acid catalyst was prepared by depositing the carbon precursor onto glass, ceramic and aluminum supports via dip-coating method, followed by carbonization process for converting the d-glucose layer into black carbon char in an inert nitrogen environment at 400 °C. Then, the –SO3H group was introduced into the framework of the carbon char by multiple vapor phase sulfonation. Four different carbonization methods were carried out (dry pyrolysis and hydrothermal carbonization with or without pressurized in the catalyst preparation while among the carbonization methods, the samples which prepared from dry pyrolysis without pressurized process showed the strong acidity due to highest adsorption of acid group in the catalyst surface although the catalyst attached onto the support was the least compared to other preparation methods. Among the catalysts, the sulfonated carbon-base catalyst that is attached on the ceramic support exhibited the highest aci-dity (1.327 mmol/g followed by the catalyst deposited on the glass (0.917 mmol/g and aluminum (0.321 mmol/g supports. The porous structure of ceramic surface, allowed a better interaction between reactants and –SO3H site in the carbon. Through the FT-IR analysis, it was observed that the functional groups –COOH, –OH, and –SO3H were present in the active sites of the catalysts. The surface areas of  glass (Si–SC, ceramic (Ce–SC and aluminum (Al–SC catalysts were larger than 1 m2/g, whereas the pore size belongs to macroporous as the average pore size is more than 50 nm. It is also stable within the temperature of 400 °C as there was less than 10% weight loss revealed from the TGA analysis. Copyright © 2017 BCREC GROUP. All rights reserved Received: 20th April 2016; Revised: 14th October 2016; Accepted: 17th October 2016 How to Cite: Janaun, J.A., Mey, T.J., Bono, A., Krishnaiah, D. (2017. Preparation and Characterization of Sugar Based Catalyst on Various

  15. Preparation of arrays of long carbon nanotubes using catalyst structure

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuntian T.; Arendt, Paul; Li, Qingwen; Zhang, Xiefie

    2016-03-22

    A structure for preparing an substantially aligned array of carbon nanotubes include a substrate having a first side and a second side, a buffer layer on the first side of the substrate, a catalyst on the buffer layer, and a plurality of channels through the structure for allowing a gaseous carbon source to enter the substrate at the second side and flow through the structure to the catalyst. After preparing the array, a fiber of carbon nanotubes may be spun from the array. Prior to spinning, the array can be immersed in a polymer solution. After spinning, the polymer can be cured.

  16. Characterisation of the surface of freshly prepared precious metal catalysts.

    Science.gov (United States)

    Parker, Stewart F; Adroja, Devashibhai; Jiménez-Ruiz, Mónica; Tischer, Markus; Möbus, Konrad; Wieland, Stefan D; Albers, Peter

    2016-07-14

    A combination of electron microscopy, X-ray and neutron spectroscopies and computational methods has provided new insights into the species present on the surface of freshly prepared precious metal catalysts. The results show that in all cases, at least half of the surface is metallic or nearly so, with the remainder covered by oxygen, largely as hydroxide. Water is also present and is strongly held; weeks of pumping under high vacuum is insufficient to remove it. The hydroxyls are reactive as shown by their reaction with or displacement by CO and can be removed by hydrogenation. This clearly has implications for how precious metal catalysts are activated after preparation.

  17. Applications and Preparation Methods of Copper Chromite Catalysts: A Review

    Directory of Open Access Journals (Sweden)

    Ram Prasad

    2011-11-01

    Full Text Available In this review article various applications and preparation methods of copper chromite catalysts have been discussed. While discussing it is concluded that copper chromite is a versatile catalyst which not only catalyses numerous processes of commercial importance and national program related to defence and space research but also finds applications in the most concerned problem worldwide i.e. environmental pollution control. Several other very useful applications of copper chromite catalysts are in production of clean energy, drugs and agro chemicals, etc. Various preparation methods about 15 have been discussed which depicts clear idea about the dependence of catalytic activity and selectivity on way of preparation of catalyst. In view of the globally increasing interest towards copper chromite catalysis, reexamination on the important applications of such catalysts and their useful preparation methods is thus the need of the time. This review paper encloses 369 references including a well-conceivable tabulation of the newer state of the art. Copyright © 2011 by BCREC UNDIP. All rights reserved.(Received: 19th March 2011, Revised: 03rd May 2011, Accepted: 23rd May 2011[How to Cite: R. Prasad, and P. Singh. (2011. Applications and Preparation Methods of Copper Chromite Catalysts: A Review. Bulletin of Chemical Reaction Engineering & Catalysis, 6 (2: 63-113. doi:10.9767/bcrec.6.2.829.63-113][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.829.63-113 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/829 ] | View in 

  18. Synthesis and Characterization of Ni/Hydrotalcite and Its Application in Hydrocracking Calophyllum Inophyllum Oil

    Directory of Open Access Journals (Sweden)

    Hafshah

    2016-12-01

    Full Text Available This research aims to synthesize hydrotalcite as an alternatives of catalyst support of hydrocracking of vegetable oils. Hydrotalcite can be synthesized in several ways, the most common is coprecipitation method. Hydrotalcite was synthesized using Mg/Al mole ratio of 1: 1, NaOH and Na2CO3 as base solutions. Ni/hydrotalcite catalyst was synthesized by incipicient wetness impregnation method with Ni impregnation of 10% w/w. The characterization of the crystal structure was determined by X-ray diffraction (XRD. The spesific surface area (SBET was determined by adsorption-desorption of nitrogen, it were obtained 201 m2/g after impregnation and 191 m2/g before impregntion. The test of performance of catalyst was conducted by hydrocracking reaction of Calophyllum inophyllum oil. The liquid products were analyzed by gas chromatography mass spectrometry (GC-MS. Hydrocracking process produced gasoline, kerosene, gas oil with yield of 0.36%, 2.45%, 54.88% respectively, conversion of 96.26% and selectivity of gas oil of 84.39%.

  19. Phenolate constrained geometry polymerization catalyst and method for preparing

    Science.gov (United States)

    Marks, Tobin J.; Chen, You-Xian

    1999-01-01

    The subject invention involves a method of preparing and the constrained geometry catalyst thereby prepared of the general formula Ar'R4(O)Ar"R'.sub.4 M(CH.sub.2 Ph).sub.2 where Ar' is a phenyl or naphthyl group; Ar" is a cyclopentadienyl or indenyl group, R and R' are H or alkyl substituents (C.ltoreq.10) and M is Ti, Zr or Hf. The synthetic method involves a simple alkane elimination approach which permits a "one-pot" procedure. The catalyst, when combined with a cocatalyst such as Pb.sub.3 C.sup.+ B(Ar.sub.3.sup.F).sub.4 BAr.sub.3.sup.F or methyl alumoxane where Ar.sup.F is a fluoroaryl group, is an effective catalyst for the polymerization of .alpha.-olefins such as ethylene, propylene and styrene.

  20. Synthetic rubbers prepared by lanthanide coordination catalysts

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China is rich in rare earth resources. Rare earth elements, also named lanthanides, are number 58 to number 81 elements in the elemental periodic table. They have unique electronic structures and may form various coordination compounds. In the early 1960s, researchers at the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (CIAC) found the catalytic activities of lanthanide compounds in stereospecific polymerization of conjugated dienes, and published the first paper on this topic in 1964. On the basis of this finding, CIAC launched extensive research activities on lanthanide compounds as diene polymerization catalysts, from a series of fundamental research to the efforts of industrializing the rare earth catalyzed cis-1,4-polybutatine rubber and cis-1,4-polyisoprene rubber. This review aims to summarize the progress in this field in the past half century.

  1. Synthetic rubbers prepared by lanthanide coordination catalysts

    Institute of Scientific and Technical Information of China (English)

    CHEN WenQi; WANG FoSong

    2009-01-01

    China is rich in rare earth resources. Rare earth elements, also named Ianthanides, are number 58 to number 81 elements in the elemental periodic table. They have unique electronic structures and may form various coordination compounds. In the early 1960s, researchers at the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (CIAC) found the catalytic activities of lanthanide compounds in stereospecific polymerization of conjugated dienes, and published the first paper on this topic in 1964. On the basis of this finding, CIAC launched extensive research activities on lanthanide compounds as diene polymerization catalysts, from a series of fundamental research to the efforts of industrializing the rare earth catalyzed cis~(-1),4-polybutatine rubber and cis~(-1),4-polyisoprene rubber. This review aims to summarize the progress in this field in the past half century.

  2. Hydrodesulfurization catalyst prepared by urea-matrix combustion method

    Institute of Scientific and Technical Information of China (English)

    Dongmei Jiao; Yeyong Ma; Fahai Cao

    2012-01-01

    Co-Mo/γ-Al2O3-TiO2 hydrodesulfurization (HDS) catalyst samples prepared by a urea matrix combustion (UMxC) method,were evaluated in a stainless tubular fixed-bed reactor,with thiophene,benzothiophene and dibenzothiophene in xylene as model feedstocks.The samples were pre-sulfurized using a cyclohexane solution of 3% CS2 and then tested for the HDS reaction.The test results were compared with catalysts prepared by conventional methods involving sequential impregnation (SI) and co-impregnation (CI).The catalysts were characterized using X-ray diffraction (XRD),laser Raman spectroscopy (LRS),high resolution transmission electron microscopy (HRTEM) and N2 physisorption,showing that the UMxC catalyst had higher pore volume and surface area than those prepared by the CI and SI methods.The UMxC method increased metal loading and avoided formation of inert phase,e.g.,β-CoMoO4,for the HDS reaction,suggesting that UMxC method is superior to the conventional impregnation techniques.TiO2 promoter made particles on the catalyst surface closer and alleviated the interaction between molybdenum oxide and the support,and facilitated the formation of well-dispersed Co- and Mo-oxo species on catalyst surface,thus resulting in higher HDS catalytic activity than pure -γ-Al2O3 support without modifiers.Consequently,the addition of TiO2 obviously improved the HDS conversion of dibenzothiophene.

  3. Sodium phosphate as a solid catalyst for biodiesel preparation

    Directory of Open Access Journals (Sweden)

    S. T. Jiang

    2010-03-01

    Full Text Available Sodium phosphate (Na3PO4 was chosen as catalyst for biodiesel preparation from rapeseed oil. The effects of mass ratio of catalyst to oil, molar ratio of methanol to oil, reaction temperature and rotation speed on biodiesel yield were investigated. For a mass ratio of catalyst to oil of 3%, molar ratio of methanol to oil of 9:1, reaction temperature of 343K and rotation speed of 600rpm, the transesterification was nearly completed within 20 minutes. Na3PO4 has a similar activity to homogeneous catalysts. Na3PO4 could be used repeatedly for 8 runs without any activation treatment and no obvious activity loss was observed. The concentrations of catalyst in biodiesel ranged from 0.6 to 0.7 mg/g. Compared to Na3PO4, Na3PO4.10H2O was cheaper, but the final yield was 71.3%, much lower than that of Na3PO4 at 99.7%.

  4. Preparation and Characterization of Double Metal Cyanide Complex Catalysts

    Directory of Open Access Journals (Sweden)

    Weilin Guo

    2003-01-01

    Full Text Available A series of double metal cyanide (DMC complex catalysts were prepared in two different methods by using ß-cyclodextrin, PEG-1000 and Tween-60 as an additional complex ligands respectively. It was showed that a mixture of crystalline and amorphous DMC was synthesized by using traditional method in which the additional complex ligand was added after the precipitation of DMC. Amorphous and dispersed DMC with higher activity could be obtained when the additional complex ligand was added in the reactant solution before reaction. The effect of additional complex ligand and preparation method on the crystalline state and catalytic property of DMC were also investigated.

  5. The construction of a hydrocracking installation at the Esso refinery in Rotterdam, Netherlands; Part 1 and 2. De bouw van een hydrocracker in het Esso raffinaderijcomplex in Rotterdam; Deel 1 en 2

    Energy Technology Data Exchange (ETDEWEB)

    Dijkgraaf, A.; Van Klooster, L.

    1993-03-01

    In three brief articles attention is paid to the title subject. The aim of the new hydrocracker is to produce sulfur-lean diesel oil. The first article highlights the composition of the project team, which consists of Esso employees, and the main contractor Fluor Daniels. Also important is to form a multi-disciplinary team of engineers. In the second article attention is paid to the importance of redundancy in the electric system of the hydrocracker. The chance of power supply failures is reduced considerably by means of a triple safety control with an error tolerance, which stops the hydrocracker when two of three meters report an error. For the third article a separate abstract has been prepared

  6. PREPARATION OF MESOPOROUS CARBON BY CARBON DIOXIDE ACTIVATION WITH CATALYST

    Institute of Scientific and Technical Information of China (English)

    W.Z.Shen; A.H.Lu; J.T.Zheng

    2002-01-01

    A mesoporous activated carbon (AC) can be successfully prepared by catalytic activa-tion with carbon dioxide. For iron oxide as catalyst, there were two regions of mesoporesize distribution, i.e. 2-5nm and 30-70nm. When copper oxide or magnesium oxidecoexisted with iron oxide as composite catalyst, the content of pores with sizes of 2-5nm was decreased, while the pores with 30 70nm were increased significantly. Forcomparison, AC reactivated by carbon dioxide directly was also investigated. It wasshown that the size of mesopores of the resulting AC concentrated in 2-5nm with lessvolume. The adsorption of Congo red was tested to evaluate the property of the result-ing AC. Furthermore, the factors affecting pore size distribution and the possibility ofmesopore formation were discussed.

  7. Hydrocracking of waste chicken fat as a cost effective feedstock for renewable fuel production: A kinetic study

    Directory of Open Access Journals (Sweden)

    Samia A. Hanafi

    2016-12-01

    Full Text Available In this study, low cost waste chicken fat (WCF feedstock was used for fuel-like hydrocarbon production. The effects of varying reaction parameters on the hydrocracking of waste chicken fat using NiW/SiO2–Al2O3 catalyst were investigated. The reactions were carried out in a fixed bed down flow reactor at reaction temperatures of 400–450 °C, liquid hourly space velocity (LHSV of 1, 2, 4 h−1, H2/oil molar ratio of 450 v/v and hydrogen pressures of 6.0 MPa. The effects on hydrocracking conversion and distribution of products were investigated. The liquid product was analyzed using gas chromatography (GC to quantify n-alkanes. Hydrocracking conversion and organic liquid products (OLPs were evaluated by ASTM D-2887 distillation. The results showed that the catalytic hydrocracking of WCF generates fuels that have chemical and physical properties comparable to those specified for petroleum-based fuels. The amount of kerosene/diesel fractional product decreased with an increase in the temperature and a decrease in the LHSV; while gasoline like petroleum fuel increased. A considerable elimination of O2 from chicken waste fat molecules has been indicated by FTIR analysis. The oxygen removal pathway of WCF over NiW/SiO2–Al2O3 catalyst is primarily carried out by hydro-deoxygenation. The reaction was found to follow the second order mechanism, and the estimated activation energy Ea was 96 kJ mol−1. The exploited catalyst was employed in another run where the results showed the catalyst stability and can be used for several times.

  8. Preparation and Cracking Performance of FCC Co-Catalyst for Enhancing Light Oil Production

    Institute of Scientific and Technical Information of China (English)

    Wu Feiyue; Shi Li; Weng Huixin; Wang Xin

    2008-01-01

    In this paper,a FCC co-catalyst for enhancing the light oil production was prepared by the sol-gel method,and its effect on the performance of residue cracking catalysts was evaluated in a CCFFB reactor.The test results indicated that the liquid product yield increased obviously,after the surface of FCC equilibrium catalyst was impregnated with the co-catalyst.The yields of dry gas,slurry and coke decreased,while the diesel yield changed slightly.And the crackability of residue was increased; the rate of coke deposition on catalyst surface was decreased,with the thermal cracking reactions inhibited.All these results showed that the co-catalyst could improve the density of acid sites and change the catalyst acidity,which could promote to prolong the catalyst activity by depositing the co-catalyst on the surface of FCC equilibrium catalysts.

  9. Formation of alkanes alkylcycloalkanes and alkylbenzenes during the catalytic hydrocracking of vegetable oils

    Energy Technology Data Exchange (ETDEWEB)

    Filho, G.N. da Rocha; Brodzki, D.; Djega-Mariadassou, G. (Universite Pierre et Marie Curie, Paris (France). Lab. Reactivite de Surface et Structure)

    1993-04-01

    Catalytic hydrocracking of vegetable oils was performed in the presence of a NiMo/[gamma]-Al[sub 2]O[sub 3] catalyst sulfided in situ with elemental sulfur under hydrogen pressure. Various vegetable oils were selected to study the effect of the degree of saturation and lateral chain length: [ital Passiflora edulis] (maracuja), [ital Astrocaryum vulgare] (tucuma), [ital Mauritia flexuosa] (buriti), [ital Orbygnya martiana] (babassu) and soybean. The effects of reaction temperature and hydrogen pressure in cyclization were studied. Carboxylic acids were used as model compounds. 29 refs., 5 figs., 5 tabs.

  10. Hydrothermally Stable Fe–W–Ti SCR Catalysts Prepared by Deposition–Precipitation

    DEFF Research Database (Denmark)

    Putluru, Siva Sankar Reddy; Schill, Leonhard; Mossin, Susanne;

    2014-01-01

    Fe/TiO2 based catalysts were prepared by incipient wetness impregnation and deposition–precipitation (DP). The catalysts were characterized by activity measurements, N2 physisorption, X-ray powder diffraction, electron paramagnetic resonance spectroscopy, energy dispersive X-ray spectroscopy, H2-.......Relative SCR activity of catalysts at 450 °C....

  11. Preparation-Properties Relation of Mn-Cu Hopcalite Catalyst

    Directory of Open Access Journals (Sweden)

    Ardita Mele

    2012-01-01

    Full Text Available Problem statement: The Mn-Cu hopcalite catalyst was used for the conversion of CO to CO2 at low temperatures. It was the catalyst of choice in the gas masks for respiratory protection in mines, aircrafts, military, spatial laboratories. Approach: The efficiency of hopcalite catalyst depends on its surface parameters. Its surface characteristics can be influenced from the chosen way of the MnO2 and CuO precipitation and from the pressure of pelletizing. Results: The hopcalite samples has been prepared by precipitation of MnO2 and by adding CuSO4 further in the solution the adsorption of Cu2+ ions on MnO2 particles surface is achieved. After acidification of the solution up to pH = 3 the copper is precipitated in form of Cu (OH2CuCO3 by adding NaHCO3. Precipitate was washed, dried, pressed, crushed, sieved (1-2 mm and calcined at 180°C for 3 h. MnO2 and hopcalite samples were characterized by XRD. The activity was evaluated by determination of its protection time and it was 610 min, better than activity of a commercial catalyst. Specific surface area, pore volume and density were measured by nitrogen adsorption and mercury intrusion porosimetry. The X-Ray diffractograms shows that the only crystallinity of hopcalite comes from MnO2, which is present mainly in amorphous form. By increasing the pressure in the pelletizing step, a significant decrease in the specific surface area (247.64-147.77 m2 g-1 and in the total pore volume (446-278 mm3 g-1 is observed in the hopcalite samples. Conclusion: The obtained hopcalite catalyst by the two step precipitation method shows high catalytic activity. The increasing pressure increases the strength and reduces the specific surface area and pore volume. A pressure of 500 kg cm-2 is recommended for the hopcalite production procedure.

  12. The effects of Te on the performance of Mo-V catalysts prepared by hydrothermal synthesis

    Institute of Scientific and Technical Information of China (English)

    Hua Chang Jiang; Ling Zeng; Bin Long Yin

    2007-01-01

    Some Mo-V-Te-La catalysts with varied component were prepared by hydrothermal synthesis and dried with microwave method. The component of the catalyst were greatly affected the crystal structure and Raman spectrum. The phase in the catalysts was different when the Mo, V, and Te content varied. When the catalyst containing the same Mo, V content, due to the effect of dopant of Te element (V0.07 Mo0.93)5O14 became the main phase in the catalyst. The catalyst also showed good activity for the reaction of selective oxidation propane to acrolein and acrylic acid.

  13. Preparation and characterizations of Ce-Cu-O monolithic catalysts for ethyl acetate catalytic combustion

    Institute of Scientific and Technical Information of China (English)

    马瑞红; 苏孝文; 金凌云; 鲁继青; 罗孟飞

    2010-01-01

    Ce-Cu-O monolithic catalysts were prepared by using Ce0.9Cu0.1O1.9 solid solution or nitrate as precursors,and their catalytic performance for the combustion of ethyl acetate were studied.The catalysts calcined at a low temperature showed high catalytic activities.When calcined at high temperatures,the catalyst with Ce0.9Cu0.1O1.9 solid solution as precursor remained a high activity,while the catalyst with metal nitrates as precursors exhibited a suppressed reactivity.Therefore,the catalyst prepared with th...

  14. PREPARATION OF Au/SULFONATED POLYSTYRENE CATALYSTS FOR LOW-TEMPERATURE CO OXIDATION

    Institute of Scientific and Technical Information of China (English)

    Shi-hua Wu; Xiu-cheng Zheng; Wei-ping Huang; Shou-min Zhang; Wei Wei

    2001-01-01

    Supported Au catalysts for low-temperature CO oxidation were prepared by solvated metal atom impregnation (SMAI) and conventional impregnation (CI). X-ray photoelectron spectroscopy (XPS) investigations indicated that the elemental gold in all the samples was in the metallic state. XRD measurements showed that the mean diameters of Au particles prepared by SMAI were smaller than those prepared by CI with the same gold content. Catalytic tests showed that the SMAI catalyst had higher CO oxidation activity than the CI catalyst with the same compositions. Both SMAI and CI catalysts exhibited high activity in Iow temperature CO oxidation. Full CO conversion was obtained at 323-383K.``

  15. Various conformations of carbon nanocoils prepared by supported Ni-Fe/molecular sieve catalyst.

    Science.gov (United States)

    Yang, Shaoming; Chen, Xiuqin; Takeuchi, K; Motojima, Seiji

    2006-01-01

    The carbon nanocoils with various kinds of conformations were prepared by the catalytic pyrolysis of acetylene using the Ni metal catalyst supported on molecular Sieves which was prepared using Fe-containing kaolin as the raw material. There are four kinds of carbon nanocoils conformations produced by this catalyst. The influences of reaction temperature and gas conditions on the conformations of the nanocoils were investigated and the reasons of forming nano-size coils were discussed by comparison with pure Ni metal catalyst.

  16. Oxidation of Carbon Monoxide over Cu/CeO2 Catalysts Prepared by SMAI

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Supported Cu catalysts for low-temperature CO oxidation were prepared by solvated metal atom impregnation (SMAI). X-ray photoelectron spectroscopy (XPS) investigations indicated that the copper in all the samples was in a metallic state. XRD measurements showed that the mean diameters of Cu particles prepared by SMAI were small. Catalytical tests showed that the SMAI catalyst had high CO oxidation activity.

  17. Zinc Oxide Hydrogen Sulfide Removal Catalyst/ Preparation, Activity Test and Kinetic Study

    Directory of Open Access Journals (Sweden)

    Ameel. M. Rahman

    2008-01-01

    Full Text Available Hydrogen sulfide removal catalyst was prepared chemically by precipitation of zinc bicarbonate at a controlled pH. The physical and chemical catalyst characterization properties were investigated. The catalyst was tested for its activity in adsorption of H2S using a plant that generates the H2S from naphtha hydrodesulphurization and a unit for the adsorption of H2S. The results comparison between the prepared and commercial catalysts revealed that the chemical method can be used to prepare the catalyst with a very good activity.It has observed that the hydrogen sulfide removal over zinc oxide catalyst follows first order reaction kinetics with activation energy of 19.26 kJ/mole and enthalpy and entropy of activation of 14.49 kJ/mole and -220.41 J/mole respectively.

  18. Influence of preparation method on performance of a metal supported perovskite catalyst for combustion of methane

    Institute of Scientific and Technical Information of China (English)

    翟彦青; 熊杰明; 李翠清; 徐新; 罗国华

    2010-01-01

    A different method was employed for the preparation of a metal supported perovskite catalyst for the catalytic combustion of methane.The prepared metallic catalysts were characterized by means of X-ray diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and also by ultrasonic and thermal shock tests and catalytic activity.It was found that the process factors during the preparation,e.g.the preparation of the catalyst precursor and the coating slurry,the calcination te...

  19. Thermodynamics of hydrocracking and isomerization reaction of Fischer-Tropsch syncrude%费托合成油品加氢裂化异构化反应的热力学

    Institute of Scientific and Technical Information of China (English)

    吴建民; 孙启文; 张宗森; 庞利峰

    2014-01-01

    into account all the reactions.The occurrence of the hydrocracking and isomerization reaction of alkene is easier than that of alkane.The thermodynamic data obtained can provide the theoretical basis for the study of hydrocracking and isomerization reaction of Fischer-Tropsch syncrude process, reactor development and new catalyst preparation.

  20. Hydrocracking of heavy ends to light hydrocarbons for steam-crackers feed

    Energy Technology Data Exchange (ETDEWEB)

    Cesana, A.; Buzzoni, R. [Eni S.p.A., Research Centre for Non-Conventional Energies, Novara (Italy). Ist. Eni Donegani

    2010-12-30

    Low value aromatic fractions, i.e. heavy pygas and pyrolysis fuel oil from naphtha steamcrackers or heavy distillates and ends from refinery, can be conveniently upgraded as high quality steamcracker feeds by severe hydrocracking treatment at 450 -530 C, 6 MPa H{sub 2} employing Ni-Mo or Zn-Mo on H-USY zeolite as catalysts. The process mainly leads to linear C{sub 2}-C{sub 4} alkanes with a low yield to CH{sub 4}. The robust catalytic system allows upgrading fractions with a high content of sulfur and nitrogen. Catalyst life and industrial feasibility have been assessed by long life runs using genuine industrial feedstocks. (orig.)

  1. Application of Discrete Lumped Kinetic Modeling on Vacuum Gas Oil Hydrocracking

    Institute of Scientific and Technical Information of China (English)

    Han Longnian; Fang Xiangchen; Peng Chong; Zhao Tao

    2013-01-01

    The kinetic model of vacuum gas oil (VGO) hydrocracking based on discrete lumped approach was investigated, and some improvement was put forward at the same time in this article. A parallel reaction scheme to describe the conver-sion of VGO into products (gases, gasoline, and diesel) proposed by Orochko was used. The different experimental data were analyzed statistically and then the product distribution and kinetic parameters were simulated by available data. Fur-thermore, the kinetic parameters were correlated based on the feed property, reaction temperature, and catalyst activity. An optimization code in Matlab 2011b was written to ifne-tune these parameters. The model had a favorable ability to predict the product distribution and there was a good agreement between the model predictions and experiment data. Hence, the ki-netic parameters indeed had something to do with feed properties, reaction temperature and catalyst activity.

  2. PROPERTIES OF POLYMER SUPPORTED Ni-Cu BIMETALLIC CATALYSTS PREPARED BY SOLVATED METAL ATOM IMPREGNATION

    Institute of Scientific and Technical Information of China (English)

    WU Shihua; ZHU Changying; HUANG Wenqiang

    1996-01-01

    D-72 resin supported nickel-copper catalysts prepared by solvated metal atom impregnation (SMAI) were studied by magnetic measurements and X-ray photoelectron spectroscopy (XPS). The Ni particles on the catalysts are very highly dispersed and display superparamagnetic behaviour. Ni-Cu alloy clusters were found to be formed. The surface compositions are different from the bulk concentrations. In contrast with the surface enrichment in copper generally observed on conventional Ni-Cu catalysts, the surfaces of these catalysts are enriched in nickel. The nickel is in both zero and valent states, while copper is mainly in metallic state. Catalytic data show that the formation of Ni-Cu alloy clusters has a profound effect on the catalytic activities of the catalysts in the hydrogenation of furfural. The activity of the Ni:Cu ratio of one bimetallic catalysts is much higher than that of the Ni or Cu monometallic catalyst.

  3. PREPARATION OF CUO/γ-Al2O3 CATALYSTS FOR CATALYTIC COMBUSTION VOCS VIA PLASMA

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    CuO/γ-Al2O3 catalysts were prepared by plasma treatment and conventional impregnation methods. The catalytic combustion of two kinds of volatile organic compounds (VOCs), toluene and benzene, were carried out over these CuO/γ-Al2O3 catalysts. The surface properties of these catalysts were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The experimental results showed that in catalytic combustion the activity of the CuO/γ-Al2O3 catalyst prepared via plasma was much higher than that of the CuO/γ-Al2O3 catalyst prepared by conventional impregnation method. XRD results showed that an enhanced dispersion had been achieved with the plasma treatment. SEM results indicated that the size became much smaller and the surface became more uniform with the plasma treatment.

  4. Preparation Of KF-Modified Kaolinite As Green And Reusable Catalyst For Microwave Assisted Biodiesel Conversion

    Science.gov (United States)

    Fatimah, I.; Andiena, R. Z.; Yudha, S. P.

    2017-02-01

    Preparation of KF-modified kaolinite catalyst for microwave-assisted biodiesel conversion has been investigated. Kaolinite modification was conducted by solid-solid reaction between naturally occurring kaolinite mineral and KF salt followed by heating at 200oC for 2h. Prepared catalyst was characterized by using XRD, BET surface area analyzer, and SEM-EDX analysis and for catalytic activity tests, biodiesel conversion of jatropha oil was simulated. The comparison between microwave utilization and conventional method of biodiesel conversion were studied, moreover study on the catalyst reusability was performed. The results show that prepared catalyst gives the better physicochemical character of kaolinite as heterogeneous catalysts application as shown by the higher conversion and also reusability. Furthermore, the use of microwave irradiation exhibits the more time effectiveness. In general, the greener biodiesel conversion using presented methods is promising technique to be developed.

  5. Production of hydrogen from methanol over binary Cu/ZnO catalysts Part I. Catalyst preparation and characterisation

    NARCIS (Netherlands)

    Melián-Cabrera, Ignacio; Boutonnet, Magali; Agrell, Johan; Fierro, José L.G.

    2003-01-01

    Mixed copper–zinc oxide catalysts (Cu/ZnO) were prepared by two different techniques, i.e. from hydroxycarbonate precursors formed in aqueous solution and from oxalate precursors formed in water-in-oil microemulsion. Their physicochemical properties were characterised by nitrogen adsorption–desorpti

  6. Production of hydrogen from methanol over binary Cu/ZnO catalysts Part I. Catalyst preparation and characterisation

    NARCIS (Netherlands)

    Melián-Cabrera, Ignacio; Boutonnet, Magali; Agrell, Johan; Fierro, José L.G.

    2003-01-01

    Mixed copper–zinc oxide catalysts (Cu/ZnO) were prepared by two different techniques, i.e. from hydroxycarbonate precursors formed in aqueous solution and from oxalate precursors formed in water-in-oil microemulsion. Their physicochemical properties were characterised by nitrogen

  7. Comparison of Preparation Methods of Copper Based PGMFree Diesel-Soot Oxidation Catalysts

    Directory of Open Access Journals (Sweden)

    R. Prasad

    2011-05-01

    Full Text Available CuO-CeO2 systems have been proposed as a promising catalyst for low temperature diesel-soot oxidation. CuO-CeO2 catalysts prepared by various methods were examined for air oxidation of the soot in a semi batch tubular flow reactor. The air oxidation of soot was carried out under tight contact with soot/catalyst ratio of 1/10. Air flow rate was 150 ml/min, soot-catalyst mixture was 110 mg, heating rate was 5 0C/min. Prepared catalysts were calcined at 500 0C and their stability was examined by further heating to 800 0C for 4 hours. It was found that the selectivity of all the catalysts was nearly 100% to CO2 production. It was observed that the activity and stability of the catalysts greatly influenced by the preparation methods. The strong interaction between CuO and CeO2 is closely related to the preparation route that plays a crucial role in the soot oxidation over the CuO-CeO2 catalysts. The ranking order of the preparation methods of the catalysts in the soot oxidation performance is as follows: sol-gel > urea nitrate combustion > Urea gelation method > thermal decomposition > co-precipitation. Copyright © 2011 BCREC UNDIP. All rights reserved.(Received: 27th June 2010, Revised: 7th August 2010; Accepted: 13rd October 2010[How to Cite: R. Prasad, V.R. Bella. (2011. Comparison of Preparation Methods of Copper Based PGMFree Diesel-Soot Oxidation Catalysts. Bulletin of Chemical Reaction Engineering and Catalysis, 6(1: 15-21. doi:10.9767/bcrec.6.1.822.15-21][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.1.822.15-21 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/822 | View in 

  8. Chemical Preparation of Supported Bimetallic Catalysts. Gold-Based Bimetallic, a Case Study

    OpenAIRE

    Louis, Catherine

    2016-01-01

    International audience; This review focuses on the chemical methods used to prepare supported bimetallic heterogeneous catalysts, i.e., bimetallic nanoparticles deposited on a support. The review is limited to the preparation of gold-based bimetallic catalysts and moreover to bimetallic nanoparticles supported on powder inorganic supports, i.e., on the surface or in the porosity, and not on model supports such as single crystals.

  9. Preparation of Pt/C Catalyst with Solid Phase Reaction Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Pt/C catalyst was prepared with solid phase reaction method (Pt/C(S)) for the first time. Its performances were compared with that prepared by the traditional liquid phase reaction method. The results demonstrate that the electrocatalytic activity of Pt/C catalyst with solid phase reaction method for methanol oxidation is higher than that with liquid phase reaction method. XRD and TEM measurements indicate that the Pt/C(S) possesses low crystalline extent and small particle size.

  10. Preparation of carbon supported Pt-P catalysts and its electrocatalytic performance for oxygen reduction

    Energy Technology Data Exchange (ETDEWEB)

    Ma Juan [Institute of Chemical Power Sources, Soochow University, Suzhou 215006 (China); Tang Yawen; Yang Gaixiu; Chen Yu [College of Chemistry and Material Science, Nanjing Normal University, Nanjing 210097 (China); Zhou Qun [Institute of Chemical Power Sources, Soochow University, Suzhou 215006 (China); Lu Tianhong [College of Chemistry and Material Science, Nanjing Normal University, Nanjing 210097 (China); Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Zheng Junwei, E-mail: jwzheng@suda.edu.cn [Institute of Chemical Power Sources, Soochow University, Suzhou 215006 (China)

    2011-05-15

    The carbon supported PtP (PtP/C) catalysts were synthesized from Pt(NO{sub 3}){sub 2} and phosphorus yellow at the room temperature. The content of P in the PtP/C catalysts prepared with this method is high and the average size of the PtP particles is decreased with increasing the content of P. The electrocatalytic performances of the PtP/C catalysts prepared with this method for the oxygen reduction reaction (ORR) are better than that of the commercial Pt/C catalyst. The promotion action of P for enhancing the electrocatalytic performance of the PtP/C catalyst for ORR is mainly due to that Pt and P form the alloy and then the electron density of Pt is decreased.

  11. Effect of preparation parameters on the microporous structure of Ni/SiO{sub 2} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Castillon, F.F.; Bodganchikova, N. [Centro de Investigacion Cientifica y de Educacion Superior, Ensenada (Mexico); Fuentes, S.; Avalos, M. [Univ. Nacional Autonoma de Mexico, Ensenada (Mexico). Inst. de Fisica

    1996-12-31

    In this work the authors report the synthesis of Ni/SiO{sub 2} catalysts promoted by group 2 (IIA) cations (calcium and barium) which are currently used as hydrogenation catalysts. The effect of the preparation parameters-aging, base agent, and type of cation, on the surface area of catalysts--is evaluated. Catalysts were prepared by precipitation of the precursor silicic acid, along with nickel nitrate and calcium and barium carbonates, with NaOH, NH{sub 4}OH and Na{sub 2}CO{sub 3} as precipitating agents. Catalysts were characterized by diffuse reflectance spectra (DRS) and by BET-surface area measurements. Results are discussed in terms of sol-gel chemistry.

  12. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANO-PARTICLE MIXED ALCOHOL CATALYSTS

    Energy Technology Data Exchange (ETDEWEB)

    Seetala V. Naidu; Upali Siriwardane; Akundi N. Murty

    2004-02-23

    The preparation of Cu, Co, Fe, Cu/Co, Cu/Fe and Co/Fe nano-particle metal loaded mesoporous 1 mm spherical granular {gamma}-Al{sub 2}O{sub 3} catalysts, by combined sol-gel/oil-drop methods followed by calcination and hydrogenation steps, is accomplished. Parameters for calcination process were optimized using DTA. The properties of metal loaded {gamma}-Al{sub 2}O{sub 3} granules were compared for the preparations starting with two precursors: aluminum tri-sec-butoxide (ALTSB) and aluminum tri-iso-propoxide (ALTIP). Three sol-gel/oil-drop catalyst preparation methods; (1) Metal nitrate solutions co-entrapped-sol-gel (2) nano-particle metal oxide co-entrapped-sol-gel, and (3) Metal impregnation on preformed alumina granules, were used. Structure and composition of metal-loaded-granules were investigated using XRD, SEM, EDX, and surface area measurements (BET method). The nano-particle nature of catalysts was confirmed using SEM and X-ray diffraction. The reduction efficiency of hydrogenation of catalysts was examined by magnetic studies using a vibrating sample magnetometer (VSM). Catalysts could be effectively calcined at 450 C and the surface area values obtained were between 200-350 m{sup 2}/g, indicating the mesoporous nature of catalyst support. Parameters affecting the metal loading process were also studied, and the optimum conditions were identified and reported for reproducible synthesis of the metal loaded {gamma}-alumina granular particles. The catalyst activities of Fe, Co, and Co/Fe on alumina for the conversion of CO/H{sub 2} and CO{sub 2}/H{sub 2} mixtures were investigated using Gas chromatography (GC) with N{sub 2} as a standard carrier gas. Both, slurry-phase-batch and gas-phase-continuous-flow, reactors were used. Magnetization studies on reduced, CO/H{sub 2} post-reaction catalyst in both gas and slurry phase were performed using vibrating sample magnetometer (VSM). Magnetic studies of post-reaction Co and Fe nano-catalysts showed that the

  13. Preparation and influence of performance of anodic catalysts for direct methanol fuel cell

    Institute of Scientific and Technical Information of China (English)

    WANG Zhenbo; YIN Geping; SHI Pengfei

    2007-01-01

    This research aims at increasing the utilization of platinum-ruthenium alloy (Pt-Ru) catalysts and thus lowering the catalyst loading in anodes for methanol electrooxidation.The direct methanol fuel cell's (DMFC) anodic catalysts,Pt-Ru/C,were prepared by chemical reduction with a reducing agent added in two kinds of solutions under different circumstances.The reducing agent was added in hot solution with the protection of inert gases or just air,and in cold solution with inert gases.The catalysts were treated at different temperatures.Their performance was tested by cyclic voltammetry and potentiostatic polarization by utilizing their inherent powder microelectrode in 0.5 mol/L CH3OH and 0.5 mol/L H2SO4 solution.The structures and micro-surface images ofthe catalysts were determined and observed by X-ray diffraction and transmission electron microscopy,respectively.The catalyst prepared in inert gases showed a better catalytic performance for methanol electrooxidation than that prepared in air.It resulted in a more homogeneous distribution of the Pt-Ru alloy in carbon.Its size is small,only about 4.5 nm.The catalytic performance is affected by the order of the reducing agent added.The performance of the catalyst prepared by adding the reductant at constant temperature of the solution is better than that prepared by adding it in the solution at 0℃ and then heating it up to the reducing temperature.The structure of the catalyst was modified,and there was an increase in the conversion of ruthenium into the alloyed state and an increase in particle size with the ascension of heat treatment temperature.In addition,the stability of the catalyst was improved after heat treatment.

  14. Preparation methods of mixed metal sulfide catalysts for deep hydrogenation of crude oils%原油深度加氢复合多金属硫化物催化剂的制备方法

    Institute of Scientific and Technical Information of China (English)

    蒋丽娟; 李来平; 张文钲

    2014-01-01

    复合多金属硫化物( MMS)催化剂主要用于原油的深度加氢,用于生产高十六烷值、低硫和低芳族化合物柴油。MMS催化剂包含NiMoS、NiWS、NiMoO、NiWO、NiMoWS和ZnMoWS催化剂等。综述MMS催化剂中二元复合金属硫化物催化剂和三元复合金属硫化物催化剂的制备方法,采用二步法即添加有机物作孔成形剂先制得催化剂前驱体,再由前驱体制得的MMS催化剂结构更松散,具有较大的比表面积(90 m2·g-1)和大孔容(大于0.3 cm3·g-1),因而具有更好的催化活性。对比不同MMS催化剂对重质柴油、焦油等的加氢裂解、加氢脱硫和加氢脱氮性能,认为NiMoW三元复合金属硫化物催化剂(50%Ni25%Mo25%W)的活性最优。%Mixed metal sulfide catalyst( MMS)catalysts are mainly used for deep hydroprocessing of refractory crudes to produce diesel oil with higher cetane number,lower sulfur and lower aromatic compounds. MMS catalysts include NiMoS,NiWS,NiMoO,NiWO,NiMoWS and ZnMoWS,etc. The preparation methods of MMS catalysts,including bi-metallic sulfide catalysts and tri-metallic sulfide catalysts,were summarized in this paper. The catalyst precursors were prepared by adding organic compounds as pore forming agents,and then the catalysts were prepared. The catalysts prepared by the two-steps method possessed dispersive structure. The attained catalyst with BET specific surface area of 90 m2·g-1 and pore volume of 0. 3 cm3 ·g-1 exhibited better catalytic activity. Compared with other several MMS catalysts,the hydrocracking,hydrodesulfurization and hydrodenitrification activities of NiMoW(50mol%Ni,25mol%Mo,25mol%W)tri-metallic sulfide catalysts for processing heavy diesel oil and tar were the best.

  15. CO oxidation on CuO/CeO{sub 2} catalyst prepared by solvothermal synthesis: influence of catalyst activation temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yuling; Mao, Dongsen, E-mail: dsmao@sit.edu.cn; Sun, Shuaishuai; Fu, Guangying [Shanghai Institute of Technology, Research Institute of Applied Catalysis, School of Chemical and Environmental Engineering (China)

    2015-12-15

    A series of CuO/CeO{sub 2} catalysts were prepared using a solvothermal method and a subsequent activation process. The influences of activation temperature (300–600 °C) on physicochemical properties and catalytic behavior of the prepared CuO/CeO{sub 2} catalysts have been investigated by XRD, SEM, Raman spectroscopy, S{sub BET} measurement, XPS surface analysis, H{sub 2}-TPR, CO-TPD techniques, and CO oxidation testing. The catalyst activated at 450 °C was found to have the highest catalytic activity, which can be ascribed to its higher dispersion of Cu species, higher concentration of oxygen vacancies, and larger amount of more active lattice oxygen. The lower activity of the CuO/CeO{sub 2} catalysts activated at lower (<450 °C) and higher (>450 °C) temperatures are attributed to the weaker interaction between CuO and CeO{sub 2}, and to the sintering of CuO nanoparticles, respectively.

  16. Cracking and hydrocracking of triglycerides for renewable liquid fuels: alternative processes to transesterification

    Energy Technology Data Exchange (ETDEWEB)

    Frety, Roger; Rocha, Maria da Graca C. da; Brandao, Soraia T., E-mail: frety@unifacs.b [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Pontes, Luiz A.M; Padilha, Jose F. [Universidade de Salvador (UNIFACS), BA (Brazil); Borges, Luiz E.P.; Gonzalez, Wilma A. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Quimica

    2011-07-01

    The most used industrial processes for the production of liquid fuels like diesel type are based on the methanolysis and ethanolysis of various oil reactants, such as palm, soybean and rapeseed oils, in the presence of homogeneous base catalysts. However, thermal and catalytic transformations of vegetable oils using available reactors and industrial processes are possible alternatives and deserve attention. In fact, three industrial processes are operating and new projects are announced. The present work analyses the experimental studies performed up to now by Brazilian researchers in the field of cracking, catalytic cracking and hydrocracking of pure or modified vegetable oils. From the published results, some research areas for the near future are suggested. (author)

  17. Catalyst deposition for the preparation of carbon nanotubes

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is a method of depositing islands of catalyst with a predetermined density, wherein in said method comprises the steps of: obtaining a diffusion barrier covered nano patterned surface comprising a plurality of plateaus, having a density of plateaus dependent on the predetermined density...... patterned surface is configured to ensure that no more than a single island of catalyst is formed on each plateau, so that a sub sequent growth of carbon nanotubes from the deposited islands result in that no more than a single carbon nanotube is grown from each plateau....

  18. Preparation of ZnNiMo/{gamma}-alumina catalysts from recycled Ni for hydrotreating reactions

    Energy Technology Data Exchange (ETDEWEB)

    Linares, Carlos F.; Lopez, Julio [Laboratorio de Catalisis y Metales de Transicion, Facultad de Ciencias y Tecnologia, Departamento de Quimica, Universidad de Carabobo, Valencia Edo Carabobo, Apartado Postal 3336 (Venezuela); Scaffidi, Adriana; Scott, Carlos E. [Centro de Catalisis, Petroleo y Petroquimica, Universidad Central de Venezuela, Facultad de Ciencias, Apartado 47102, Los Chaguaramos, Caracas (Venezuela)

    2005-09-18

    Ni, recovered from Ni-Cd cellular phone batteries, was used in the preparation of ZnNiMo/Al{sub 2}O{sub 3} catalysts. The catalysts were characterized by temperature programmed reductions (TPR), surface area determinations (BET) and chemical analysis. Vanadyl octaethyl porphyrin (VOOEP) hydrodeporphyrinization (HDP) and thiophene hydrodesulfurization (HDS) were used as catalytic tests. It was found that the addition of Zn increases the ratio between octahedral and tetrahedral Mo in ZnMo and ZnNiMo catalysts, and that Ni addition lowers the reduction temperature of Mo species. Both results induce a positive synergetic effect for HDP and HDS reactions. An activity maximum was found for the catalyst with a Zn/(Zn+Ni) atomic ratio equal to 0.29, for both reactions. Finally, the use of a possible pollutant (Ni-Cd batteries) to produce a catalyst to eliminate contaminants in fuels was shown to be feasible.

  19. Preparation and performance of rare earth Zr catalyst for reforming waste plastics cracking product

    Institute of Scientific and Technical Information of China (English)

    袁兴中; 曾光明; 陈晓青; 陈志勇; 鄢钢

    2003-01-01

    The rare earth Zr catalyst, whose carrier was Al2O3, was prepared by co-precipitation with Zr(NO3)2,Al(NO3 )3, and(NH2)2CO as the raw materials. The obtained catalyst was used to reform the waste plastic crackingproduct. As the Zr content in the catalyst increases, the yields of gasoline, gas, and the rate of carbon deposition in-crease, but the yields of diesel and heavy oil decrease. The optimum Zr content of the catalyst is 5%. At 290 ℃,with this most suitable catalyst, the yield of liquid fuel oil is the highest, about 86.10%, and research octance num-ber(RON) of the gasoline is 92.15.

  20. Comprehensive Utilization of Filter Residue from the Preparation Process of Zeolite-Based Catalysts

    Directory of Open Access Journals (Sweden)

    Shu-Qin Zheng

    2016-05-01

    Full Text Available A novel utilization method of filter residue from the preparation process of zeolite-based catalysts was investigated. Y zeolite and a fluid catalytic cracking (FCC catalyst were synthesized from filter residue. Compared to the Y zeolite synthesized by the conventional method, the Y zeolite synthesized from filter residue exhibited better thermal stability. The catalyst possessed wide-pore distribution. In addition, the pore volume, specific surface area, attrition resistance were superior to those of the reference catalyst. The yields of gasoline and light oil increased by 1.93 and 1.48 %, respectively. At the same time, the coke yield decreased by 0.41 %. The catalyst exhibited better gasoline and coke selectivity. The quality of the cracked gasoline had been improved.

  1. Catalysts for Redesigning Principal Preparation: A Courageous Journey

    Science.gov (United States)

    Buskey, Frederick; Jacobs, Jacqueline

    2009-01-01

    A review of the research, state legislative mandates, and education department requirements (Levin, 2005; Hess & Kelly, 2005; Marzano, Water, & McNulty, 2005; N.C. House Bill 536, 2007) shows different demands for the redesign of principal licensure programs. Program redesign always has some sort of catalyst. However, just because there is…

  2. Ordered mesoporous materials as model supports to study catalyst preparation

    NARCIS (Netherlands)

    Sietsma, J.R.A.

    2007-01-01

    Catalysts are indispensable to modern-day society because of their prominent role in petroleum refining, chemical processing, and the reduction of environmental pollution. The catalytically active component often consists of small metal (oxide) particles that are supported on a carrier such as silic

  3. Simple preparation of Pd-Pt nanoalloy catalysts for methanol-tolerant oxygen reduction

    Science.gov (United States)

    He, Wei; Liu, Juanying; Qiao, Yongjin; Zou, Zhiqing; Zhang, Xiaogang; Akins, Daniel L.; Yang, Hui

    Carbon-supported Pd-Pt bimetallic nanoparticles of different atomic ratios (Pd-Pt/C) have been prepared by a simple procedure involving the complexing of Pd and Pt species with sodium citrate followed by ethylene glycol reduction. As-prepared Pd-Pt alloy nanoparticles evidence a single-phase fcc disordered structure, and the degree of alloying is found to increase with Pd content. Both X-ray diffraction and transmission electron microscopy characterizations indicate that all the Pd-Pt/C catalysts possess a similar mean particle size of ca. 2.8 nm. The highest mass and specific activity of the oxygen reduction reaction (ORR) using the Pd-Pt/C catalysts are found with a Pd:Pt atomic ratio of 1:2. Moreover, all Pd-Pt alloy catalysts exhibit significantly enhanced methanol tolerance during the ORR than the Pt/C catalyst, ensuring a higher ORR performance while diminishing Pt utilization.

  4. Pt-Ru Catalysts Prepared by a Modified Polyol Process for Direct Methanol Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Junmin; ZHU Fangfang; ZHANG Kunhua; LIU Weiping; GUAN Weiming

    2012-01-01

    Supported PtRu/C catalysts used in direct methanol fuel cells (DMFCs) were prepared by a new modified polyol method.Transmission electron microscopy (TEM),X-ray diffraction (XRD) and cyclic voltammograms (CVs) were carried out to characterize the morphology,composition and the electrochemical properties of the PtRu/C catalyst.The results revealed that the PtRu nanoparticles with small average particle size (≈2.5 nm),and highly dispersed on the carbon support.The PtRu/C catalyst exhibited high catalytic activity and anti-poisoned performance than that of the JM PtRu/C.It is imply that the modified polyol method is efficient for PtRu/C catalyst preparation.

  5. Preparation of Ni/SiO2 catalyst in ionic liquids for hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Qingming FAN; Yingxin LIU; Yifan ZHENG; Wei YAN

    2008-01-01

    A series of silica supported nickel catalysts were prepared from nickel nitrate and tetraethyl orthosilicate by the sol-gel method with the imidazolium type ionic liquids as solvents. The catalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectro-scopy (EDS). Their catalytic performances for the selective hydrogenation of cinnamaldehyde to hydrocinnamalde-hyde were investigated. The results show that the Ni/ SiO2 catalyst prepared with 1-(2-hydroxyethyl)-3-methyl-imidazolc tetrafluoroborate ionic liquid as solvent exhibits the highest catalytic activity for the reaction. Under the optimal conditions of catalyst dosage (based on the mass of cinnamaldehyde used) 10%, reaction pressure 2 MPa, temperature 373 K and reaction time 2 h, the conversion of cinnamaldehyde and the selectivity to hydrocinnamal-dehyde can reach 97.6% and 98.8%, respectively.

  6. Preparation of Cyclodextrin-Based Carbonaceous Catalyst and Its Application in the Esterification

    Institute of Scientific and Technical Information of China (English)

    SHAN Chun; QIAN Guangren

    2011-01-01

    A new carbonaceous catalyst with sulfonic acid group (-SO3H) was prepared by incomplete carbonization of β-cyclodextrin followed by sulfonation. The sulfonated amorphous carbon was characterized by IR, elemental analysis, DSC-TGA and PXRD, and the catalytic activity was investigated to be an efficient catalyst for the esterification reactions with maximum yield of 87%. The sulfonated carbonaceous catalyst was readily separated from the reaction solution and keeps approximately equal catalytic activity. The results confirm that the active centre is the hydrophilic sulfonic acid functional group in the esterification reactions.

  7. XAFS analysis of unsupported $MoS_{2}$ catalysts prepared by two methods

    CERN Document Server

    Matsubayashi, N; Imamura, M; Yoshimura, Y; Nishijima, A; Calais, C; Geantet, C

    1999-01-01

    Structural analysis by XAFS method was applied to two kinds of unsupported molybdenum disulfide catalysts. Assuming a structural model consisting of crystalline and non-crystalline parts, curve fitting analysis was performed for the $9 catalysts. The residual XAFS after subtraction of the crystalline contribution showed that the structure of the non-crystalline part was significantly different between the catalysts prepared by the two methods. It was suggested that $9 EXAFS would give the average size of the micro-domains, while other methods such as TEM and TPR would give the size of macro- domains. (6 refs).

  8. The activity of ALD-prepared PtCo catalysts for ethanol oxidation in alkaline media

    OpenAIRE

    Santasalo-Aarnio, Annukka; Sairanen, Emma; Arán-Ais, Rosa M.; Figueiredo, Marta C.; Hua, Jiang; Feliu, Juan M.; Lehtonen, Juha; Karinen, Reetta; Kallio, Tanja

    2014-01-01

    Controlled bimetallic catalyst materials can be obtained using atomic layer deposition (ALD) method. In this paper, this method was applied to prepare Pt, PtCo, and PtCoPt nanoparticle catalysts on carbon support. Their activity for ethanol oxidation was studied by various electrochemical methods and the dependency of the reaction on temperature and mass transfer was evaluated. In addition, FTIR analysis was performed to confirm the reaction products. The results showed that bimetallic PtCo e...

  9. A novel process for heavy residue hydroconversion using a recoverable pseudo-homogenous catalyst PHC system

    Energy Technology Data Exchange (ETDEWEB)

    Romocki, S.M.; Rhodey, W.G. [Mobis Energy Inc., Calgary, AB (Canada)

    2008-10-15

    This paper described a pseudo-homogenous catalyst (PHC) designed to refine heavy hydrocarbon residues containing sulfur, nitrogen, metals, and asphaltene impurities known to clog pores and deactivate traditional hydrocrackers. The heavy residue hydroconversion (HRH) process incorporated a single particle, chemically generated PHC uniformly distributed in the feed. Thermal decomposition within the reaction system of a water-in-oil emulsion containing ammonium paramolybdate was used to form molybdenum oxide, which was then sulfided within the feed in order to create an ultra-dispersed suspension of catalytically active molybdenum disulfide particles measuring between 2 and 9 nm. A proprietary online catalyst recovery and regeneration step was used to maintain high catalyst activity. The molybdenum was then recovered from a purge stream and then reintroduced to the catalyst preparation area as a catalyst precursor. After being conditioned, the feed was combined with hydrogen and a water-oil catalyst emulsion and introduced into a furnace. Heavy components were cracked, hydrogenated and converted to lighter products. The high performance catalyst system was able to convert 95 per cent of residues at pressures below 7.3 Mpa and at reaction temperatures ranging between 400 and 460 degrees C. The catalyst was tested at a pilot plant using Athabasca vacuum bottoms. It was concluded that the HRH process is now being successfully used to produce 200 barrels of heavy oil per day. Designs for commercial installations are now being prepared. 4 refs., 2 tabs., 2 figs.

  10. Glow Discharge Plasma-Assisted Preparation of Nickel-Based Catalyst for Carbon Dioxide Reforming of Methane

    Institute of Scientific and Technical Information of China (English)

    Fang Guo; Wei Chu; Jun-qiang Xu; Lin Zhong

    2008-01-01

    A plasma-assisted method was employed to prepare Ni/γ-Al2O3 catalyst for carbon dioxide reforming of methane reaction. The novel catalyst possessed higher activity and better coke-suppression performance than those of the conventional calcination catalyst. To achieve the same CH4 conversion, the conventional catalyst needed higher reaction temperature, about 50 ℃ higher than that of the N2 plasma-treated catalyst.After the evaluation test, the deactivation rate of the novel catalyst was 1.7%, compared with 15.2% for the conventional catalyst. Different from the characterization results of the calcined catalyst, a smaller average pore diameter and a higher specific surface area were obtained for the plasma-treated catalyst.The variations of the reduction peak temperatures and areas indicated that the catalyst reducibility was promoted by plasma assistance. The dispersion of nickel was also remarkably improved, which was helpful for controlling the ensemble size of metal atoms on the catalyst surface. The modification effect of plasmaassisted preparation on the surface property of alumina supported catalyst was speculated to account for the concentration increase of absorbed CO2. An enhancement of CO2 adsorption was propitious to the inhibition of carbon formation. The coke amount deposited on plasma treated catalyst was much smaller than that on the conventional catalyst.

  11. Nanosized cobalt-based catalyst prepared by supercritical phase condition for Fischer-Tropsch synthesis

    Institute of Scientific and Technical Information of China (English)

    Jingmiao Li; Jingchang Zhang; Runduo Zhang; Weiliang Cao

    2009-01-01

    A series of nanosized Co/Zn/Mn/K composite catalysts for Fischer-Tropsch synthesis (FTS) were prepared by supercritical fluid drying (SCFD) method and common drying (CD) method. The nanosized cobalt-based catalysts were characterized by XRD,TEM and BET techniques. Their catalytic performances were tested in a slurry-bed reactor under FTS reaction conditions. The drying and crystallization were carded out simultaneously during SCFD,therefore,the catalysts prepared by SCFD method have ideal structure and show the FTS performance superior to the others prepared by CD method. The FTS activity and selectivity were improved via adding Zn,Mn and K promoters,and less CH_4 and CO_2 as well as higher yield of C~(5+) products were achieved. The optimal performance of a 92% CO conversion and a 65% C~(5+) product yield was obtained over a catalyst with the component of Co/Zn/Mn/K = 100/50/10/7. Furthermore,the catalytic performance was studied under the conditions of liquid-phase and supercriticai phase slurry-bed,and C~(5+) product yield were 57.4% and 65.4%,respectively. In summary,better catalytic performance was obtained using the nanosized catalyst prepared by SCFD method under supercritical reaction conditions,resulting in higher conversion of CO,less CO_2 byproduct,and higher yield of C~(5+) products,

  12. Study of structural and catalytic properties of Ni catalysts prepared from inorganic complex precursor for Fischer-Tropsch synthesis

    Science.gov (United States)

    Saheli, Sania; Rezvani, Ali Reza; Malekzadeh, Azim

    2017-09-01

    The silica- and alumina- supported Ni catalysts synthesized by thermal decomposition of inorganic precursors were evaluated for Fischer-Tropsch synthesis (FTS); the structural properties and performance of the catalysts were compared to those of samples constructed via impregnation method. The results revealed that the synthesized catalysts have higher catalytic activity comparison to those prepared via the conventional impregnation method. The effect of the preparation method on the structural properties shows that synthesizing the catalyst through inorganic precursor route is more appropriate. Characterization of catalysts is carried out using inductively coupled plasma (ICP), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET specific surface area.

  13. Modeling and simulation of a pseudo-two-phase gas-liquid column reactor for thermal hydrocracking of petroleum heavy fractions

    Directory of Open Access Journals (Sweden)

    E.M. Matos

    2002-07-01

    Full Text Available This work presents a model to predict the behavior of velocity, gas holdup and local concentration fields in a pseudo-two-phase gas-liquid column reactor applied for thermal hydrocracking of petroleum heavy fractions. The model is based on the momentum and mass balances for the system, using an Eulerian-Eulerian approach. Using the k-epsilon model,fluid dynamics accounts for both laminar and turbulent flows, with discrete small bubbles (hydrogen flowing in a continuous pseudohomogeneous liquid phase (oil and catalyst particles. The petroleum is assumed to be a mixture of pseudocomponents, grouped by similar chemical structural properties, and the thermal hydrocracking is taken into account using a kinetic network based on these pseudocomponents.

  14. Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons

    NARCIS (Netherlands)

    Zecevic, Jovana; Vanbutsele, Gina; de Jong, Krijn P.; Martens, Johan A.

    2015-01-01

    The ability to control nanoscale features precisely is increasingly being exploited to develop and improve monofunctional catalysts(1-4). Striking effects might also be expected in the case of bifunctional catalysts, which are important in the hydrocracking of fossil and renewable hydrocarbon source

  15. Dye degradation by green heterogeneous Fenton catalysts prepared in presence of Camellia sinensis.

    Science.gov (United States)

    Carvalho, Samira S F; Carvalho, Nakédia M F

    2017-02-01

    This work describes the synthesis and characterization of supported green iron catalysts, prepared with Camellia sinensis tea extract, and their application in heterogeneous Fenton degradation of pollutant dyes. The influence of the catalyst synthesis conditions in the iron and organic content were investigated by X-ray fluorescence and thermogravimetric analyses. Irregular, chain-like nanoparticles, in the size range of 20-100 nm, capped by polyphenolic natural compounds, were visualized by TEM micrographs. TEM-EDS revealed a high iron content in the nanoparticles as well as a high carbon content all over the catalyst surface, indicating the coverage by the polyphenolic compounds of the tea. X-ray powder diffraction revealed the amorphous nature of the nanoparticles, tentatively ascribed to iron(II)/(III) oxides and oxohydroxides composites. The Fenton degradation of different dyes was successfully accomplished, leading to complete decolourization in less than 3 h of reaction. Influence of hydrogen peroxide concentration, catalyst dosage, pH, temperature and catalyst support, were investigated. The catalysts prepared with black tea over silica furnished the higher iron contents and were the most actives for dye degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Preparation of rare-earth metal complex oxide catalysts for catalytic wet air oxidation

    Institute of Scientific and Technical Information of China (English)

    LI Ning; LI Guangming; YAO Zhenya; ZHAO Jianfu

    2007-01-01

    Catalytic wet air oxidation(CWAO)is one of the most promising technologies for pollution abatement.Developing catalysts with high activity and stability is crucial for the application of the CWAO process.The Mn/Ce complex oxide catalyrsts for CWAO of high concentration phenol containing wastewater were prepared by coprecipitation.The catalyst preparation conditions were optimized by using an orthogonal layout method and single-factor experimental analysis.The Mn/Ce serial catalysts were characterized by Brunauer-Emmett-Teller(BET)analysis and the metal cation leaching was measured by inductively coupled plasma torch-atomic emission spectrometry(ICP-AES).The results show that the catalysts have high catalytic activities even at a low temperature(80℃)and low oxygen partial pressure(0.5 MPa)in a batch reactor.The metallic ion leaching is comparatively low(Mn<6.577 mg/L and Ce<0.6910 mg/L,respectively)in the CWAO process.The phenol,CODCD and TOC removal efficiencies in the solution exceed 98.5% using the optimal catalyst(named CSP).The new catalyst would have a promising application in CWAO treatment of high concentration organic wastewater.

  17. Preparation and characterization of CuO catalyst for the thermolysis treatment of distillery wastewater.

    Science.gov (United States)

    Sharma, Deepak; Prajapati, Abhinesh Kumar; Choudhary, Rumi; Kaushal, Rajesh Kumar; Pal, Dharm; Sawarkar, Ashish N

    2017-08-16

    CuO catalyst was prepared from copper sulfate by alkali precipitation method followed by drying and calcination. Characterization of CuO catalyst using X-ray diffraction, Brunauer-Emmett-Teller, and Barrett-Joyner-Halenda surface area analysis envisaged the effectiveness of CuO as a catalyst for the treatment of biodigester effluent (BDE) emanated from distilleries. The catalytic thermolysis is an efficient advance treatment method for distillery biodigester effluent (BDE). CT treatment of BDE was carried out in a 0.5 dm(3) thermolytic batch reactor using CuO as a catalyst at different pH (1-9), temperatures (80-110°C), and catalyst loadings (1-4 kg/m(3)). With CuO catalyst, a temperature of 110°C, catalyst loading of 4 kg/m(3), and pH of 2 was found to be optimal, providing a maximum reduction in chemical oxygen demand of 65%. The settling characteristics at different temperatures of CT-treated sludge were also presented.

  18. Preparation and characterization of Mn/MgAlFe as transfer catalyst for SOx abatement

    Institute of Scientific and Technical Information of China (English)

    Ruiyu Jiang; Honghong Shan; Chunyi Li; Chaohe Yang

    2011-01-01

    A series of manganese-promoted MgAlFe mixed oxides,used as sulfur transfer catalysts,were prepared by acid-processed gelatin method and characterized by TGA-DTA,XRD,N2 adsorption-desorption and FT-IR techniques.It was found that the sulfur transfer catalysts with 0.5-3.0 wt% manganese showed its good dispersion in the precursor.The novel Mn/MgAlFe catalysts with 0.5-5.0 wt% manganese oxide showed a high oxidative adsorption rate and sulfur adsorption capacity,and 5.0 wt% Mn/MgAlFe sample was superior to the others for SO2 removal.Moreover,the presence of CO had no obvious effect on the adsorption activity of sulfur transfer catalysts for SO2 uptake.

  19. Study on Carbon Nanotubes Prepared from Catalytic Decomposition of CH4 over Lanthanum Containing Ni-Base Catalysts

    Institute of Scientific and Technical Information of China (English)

    Wang Minwei; Li Fengyi

    2004-01-01

    A series of lanthanum containing Ni-base catalysts were prepared by citric acid complex method.Carbon nanotubes (CNT) were synthesized bY catalytic decomposing CH4 over these catalysts and characterized by XRD, TEM and TGA.It is found that the addition of lanthanum can not increase the yield of carbon nanotube, but can make the diameter of carbon nanotube thinner and even.The more the lanthanum addsr, the thinner the diameter of CNTs becomes.With the CNTs prepared on Ni-Mg catalyst, the CNTs prepared on Ni-La-Mg catalyst has better crystallinity and thermal stability.

  20. Catalytic Oxidation of Phenol over Zeolite Based Cu/Y-5 Catalyst: Part 1: Catalyst Preparation and Characterization

    Directory of Open Access Journals (Sweden)

    K. Maduna Valkaj

    2015-01-01

    Full Text Available The necessity to remove organic pollutants from the industrial wastewater streams has forced the development of new technologies that can produce better results in terms of pollutant removal and process efficiency in combination with low investment and operating costs. One of the new emerging processes with a potential to fulfil these demands is catalytic wet peroxide oxidation, commonly known as the CWPO process. The oxidative effect of the hydrogen peroxide is intensified by the addition of a heterogeneous catalyst that can reduce the operating conditions to atmospheric pressure and temperatures below 383 K. Zeolites, among others, are especially appealing as catalysts for selective oxidation processes due to their unique characteristics such as shape selectivity, thermal and chemical stability, and benign effect on nature and the living world. In this work, catalytic activity, selectivity and stability of Cu/Y-5 zeolite in phenol oxidation with hydrogen peroxide was examined. Catalyst samples were prepared by ion exchange method of the protonic form of commercial zeolite. The catalysts were characterized with powder X-ray diffraction (XRD, scanning electron microscopy (SEM, and AAS elemental analysis, while the adsorption techniques were used for the measurement of the specific surface area. The catalytic tests were carried out in a stainless steel Parr reactor in batch operation mode at the atmospheric pressure and in the temperature range from 323 to 353 K. The catalyst was prepared in powdered form and the mass fraction of the active metal component on the zeolite was 3.46 %. The initial concentration of phenol solution was equal to 0.01 mol dm−3 and the concentration of hydrogen peroxide ranged from 0.01 to 0.10 mol dm−3. The obtained experimental data was tested to a proposed kinetic model for phenol oxidation r = k1 cF cVP and hydrogen peroxide decomposition rHP = k2 cHP. The kinetic parameters were estimated using the Nelder

  1. The Preparation of Cu-g-C3N4/AC Catalyst for Acetylene Hydrochlorination

    Directory of Open Access Journals (Sweden)

    Wenli Zhao

    2016-12-01

    Full Text Available A novel catalyst based on g-C3N4/activated carbon was prepared by adding CuCl2. The catalytic performance of the as-prepared catalyst was investigated in the acetylene hydrochlorination reaction. X-ray photoelectron spectroscopy, temperature programmed desorption, low temperature N2 adsorption/desorption (Brunauer–Emmett–Teller, and thermal gravity analysis showed that Cu-g-C3N4/AC significantly enhanced the catalytic performance of the original catalyst by increasing the relative pyrrolic N content. Cu-g-C3N4/AC also affected the adsorption of hydrogen chloride and acetylene, as well as inhibited the coke deposition during acetylene hydrochlorination.

  2. Pt-Rh/g Al2O3 Influence of Catalyst Preparation Methods on Metallic Particle Dispersion and Size Distribution

    Directory of Open Access Journals (Sweden)

    N.M. da Fonseca

    1998-06-01

    Full Text Available - Pt-Rh/Al2O3 catalysts were prepared by successive incipient impregnations or coimpregnation. Characterization was achieved by H2 chemisorption and transmission electron microscopy. It was verified that method of preparation, ratio of metal weights and sequence of deposition are factors that result in very distinct catalysts.

  3. Impregnation of mesoporous silica for catalyst preparation studied with differential scanning calorimetry

    NARCIS (Netherlands)

    Eggenhuisen, T.M.; van Steenbergen, M.J.; Talsma, H.; de Jongh, P.E.; de Jong, K.P.

    2009-01-01

    Aqueous impregnation of mesoporous silica as a first step in catalyst preparation was studied to investigate the distribution of the metal-precursor solution over the support. The degree of pore-filling after impregnation was determined using the freezing point depression of confined liquids. A sepa

  4. Space and Time Resolved Spectroscopy during the Preparation of Hydrogenation Catalyst Bodies

    NARCIS (Netherlands)

    Espinosa Alonso, L.|info:eu-repo/dai/nl/304837342

    2009-01-01

    The development of space and time resolved spectroscopic methods to image space and time dependent heterogeneities in catalyst bodies during preparation is of paramount importance for the development of more efficient and sustainable chemical processes. There are a large number of physicochemical

  5. PREPARATION OF MULTI-WALLED CARBON NANOTUBES USING NiO CATALYST SYNTHESIZED BY HYDROTHERMAL METHOD

    Institute of Scientific and Technical Information of China (English)

    Y.J. Zhu; Y.L. Chen; X.M. Xue; Y.M. Chen; C.Y. Wu; T.C. Kuang; S.H. Li; H. Y. Zhang

    2003-01-01

    The Ni(OH)2/SiO2 binary colloid was prepared using Ni(NO3)2.6H2O and (C2H5 O)4SiO4 as starting materials and was used to form NiO/SiO2 composite powder by hydrothermal method and desiccant method in open air respectively. Multiwalled carbon nanotubes (MWCNTs) were synthesized respectively by chemical vapor deposition using the NiO/SiO2 catalyst prepared by different methods. The phase and morphology of the catalysts and the morphology, output yield and purity of MWCNTs were compared by XRD, TEM and SEM. The results show that the catalyst powder prepared by hydrothermal method, compared with that by desiccant method, is smaller, better dispersion and has stronger catalytic activity. Pure MWCNTs with smaller tube diameter and narrow range could be obtained at a high yield using that NiO/SiO.2 powder prepared by hydrothermal method as catalyst.

  6. Preparation Methods and Applications of CuO-CeO2 Catalysts: A Short Review

    Directory of Open Access Journals (Sweden)

    Ram Prasad

    2010-10-01

    Full Text Available The CuO-CeO2 catalytic systems are getting popular for catalyzing very actively the various reactions of environmental, commercial and other importance. In recent years, many methods have been in use for the preparation of versatile CuO-CeO2 catalysts. Reviewing the useful preparation methods of such catalysts is thus the need of the time in view of the globally increasing interest towards all the low temperature redox reactions. This article presents a short review on seventeen different preparation methods of the copperceria catalysts, followed by critical discussions on the related redox properties and advancements accomplished with respect to their application aspect, including a systematic compilation of the concerned newer literature in a well-concievable tabular form. ©2010 BCREC UNDIP. All rights reserved(Received: 14th January 2010, Revised: 31st January 2010, Accepted: 1st February 2010[How to Cite: R. Prasad, G. Rattan. (2010. Preparation Methods and Applications of CuO-CeO2 Catalysts: A Short Review. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (1: 7-30. doi:10.9767/bcrec.5.1.7125.7-30][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.5.1.7125.7-30 || or local:   http://ejournal.undip.ac.id/index.php/bcrec/article/view/7125

  7. Preparation Methods and Applications of CuO-CeO2 Catalysts: A Short Review

    Directory of Open Access Journals (Sweden)

    Gaurav Rattan

    2010-10-01

    Full Text Available The CuO-CeO2 catalytic systems are getting popular for catalyzing very actively the various reactions of environmental, commercial and other importance. In recent years, many methods have been in use for the preparation of versatile CuO-CeO2 catalysts. Reviewing the useful preparation methods of such catalysts is thus the need of the time in view of the globally increasing interest towards all the low temperature redox reactions. This article presents a short review on seventeen different preparation methods of the copperceria catalysts, followed by critical discussions on the related redox properties and advancements accomplished with respect to their application aspect, including a systematic compilation of the concerned newer literature in a well-concievable tabular form. ©2010 BCREC UNDIP. All rights reserved(Received: 14th January 2010, Revised: 31st January 2010, Accepted: 1st February 2010[How to Cite: R. Prasad, G. Rattan. (2010. Preparation Methods and Applications of CuO-CeO2 Catalysts: A Short Review. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (1: 7-30. doi:10.9767/bcrec.5.1.774.7-30][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.5.1.774.7-30

  8. Preparation of VPO Catalysts and Effect of Zirconium Promoter on the Selective Oxidation of Pentane

    Institute of Scientific and Technical Information of China (English)

    Chen Shengli; Lao Lihua; Shao Hancheng

    2006-01-01

    This study focuses on the effects of reducing solvents used in the preparation of vanadyl pyrophosphate (VPO), and ZrO2 and (ZrO)2P2O7 promoters on the structure and catalytic performance of VPO catalysts. The VPO catalysts were prepared by the following steps: 1) Formation of vanadium phosphate by the reaction of V2O5 and H3PO4, 2) Synthesis of VPO precursor through the reduction of vanadium phosphate by reducing solvents, and 3) Activation of the precursor. For Zr promoted VPO, Zr was added to the precursor before activation. The P/V atomic ratios of different VPO catalysts, which were prepared by using different reducing solvents, were different. The precursor prepared by using isobutanol or isobutanol-benzyl alcohol contained VO(H2PO4)2 and VOHPO4×0.5H2O. The precursor prepared by using hexanol also contained VO(H2PO4)2 and VOHPO4×0.5H2O crystal phases, but the amount of VOHPO4×0.5H2O was much less than that of VO(H2PO4)2. After activation, all the VPO catalysts, prepared by using different reducing solvents, contained only the (VO)2P2O7 crystal phase. The VPO prepared by using isobutanol-petroleum ether as reducing solvent was the most active, while the VPO prepared by using hexanol had the lowest activity. Nevertheless, their total selectivity to phthalic and maleic anhydrides was almost the same. Both ZrO2 and (ZrO)2P2O7 promoters increased the activity and selectivity of VPO, but ZrO2 promoter increased the activity of VPO more drastically than (ZrO)2P2O7 promoter.

  9. Preparation and characterization of inexpensive heterogeneous catalysts for air pollution control. Two case studies

    Energy Technology Data Exchange (ETDEWEB)

    Utsumi, Shigenori; Vallejos-Burgos, Fernando E.; Garcia, Ximena; Gordon, Alfredo L. [Department of Chemical Engineering, University of Concepcion, Concepcion (Chile); Campos, Claudia M.; Pecchi, Gina [Department of Physical Chemistry, University of Concepcion, Concepcion (Chile); Radovic, Ljubisa R. [Department of Chemical Engineering, University of Concepcion, Concepcion (Chile); Department of Energy and Geo-Environmental Engineering, The Pennsylvania State University, University Park, PA 16802 (United States)

    2007-05-30

    Relatively inexpensive heterogeneous catalysts for two reactions of great importance in air pollution control, NO reduction and VOC combustion, were prepared and characterized. Apart from their common practical goal and the frequent need for simultaneous removal of air pollutants, these reactions share a similar redox mechanism, in which the formulation of more effective catalysts requires an enhancement of oxygen transfer. For NO reduction, supported catalysts were prepared by adding a metal (Cu, Co, K) using ion exchange (IE) and incipient wetness impregnation (IWI) to chars obtained from pyrolysis of a subbituminous coal. The effects of pyrolysis temperature, between 550 and 1000 C, on selected catalyst characteristics (e.g., BET surface area, XRD spectrum, support reactivity in O{sub 2}) are reported. For IE catalysts, the surface area increased in the presence of the metals while the opposite occurred for IWI catalysts. For the Co-IE catalysts, the highest surface area was obtained at 700 C. The XRD results showed that, except for Cu (which exhibited sharp Cu{sup 0} peaks), the catalysts may be highly dispersed (or amorphous) on the carbon surface. For the C-O{sub 2} reaction the order of (re)activity was K >> Co > Cu for IE catalysts and K > Cu > Co for IWI catalysts. For NO reduction the orders were K > Co > Cu (IE catalysts) and Cu > Co > K (IWI catalysts). In all cases the catalytic (re)activity for NO reduction was lower than that exhibited for the C-O{sub 2} reaction. The K-IE and Cu-IWI catalysts appeared to be the most promising ones, although further improvements in catalytic activity will be desirable. Some surprising results regarding CO and CO{sub 2} selectivity are also reported, especially for Co catalysts. In VOC combustion, the effect of the nature of ion B (Fe and Ni) on the partial substitution of ion A (Ca for La) in ABO{sub 3} perovskites (e.g., LaFeO{sub 3} and LaNiO{sub 3}) and on their catalytic activity was studied. The perovskite

  10. Multi-Directional Growth of Aligned Carbon Nanotubes Over Catalyst Film Prepared by Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Zhou Kai

    2010-01-01

    Full Text Available Abstract The structure of vertically aligned carbon nanotubes (CNTs severely depends on the properties of pre-prepared catalyst films. Aiming for the preparation of precisely controlled catalyst film, atomic layer deposition (ALD was employed to deposit uniform Fe2O3 film for the growth of CNT arrays on planar substrate surfaces as well as the curved ones. Iron acetylacetonate and ozone were introduced into the reactor alternately as precursors to realize the formation of catalyst films. By varying the deposition cycles, uniform and smooth Fe2O3 catalyst films with different thicknesses were obtained on Si/SiO2 substrate, which supported the growth of highly oriented few-walled CNT arrays. Utilizing the advantage of ALD process in coating non-planar surfaces, uniform catalyst films can also be successfully deposited onto quartz fibers. Aligned few-walled CNTs can be grafted on the quartz fibers, and they self-organized into a leaf-shaped structure due to the curved surface morphology. The growth of aligned CNTs on non-planar surfaces holds promise in constructing hierarchical CNT architectures in future.

  11. TiO2 preparation by improved homogeneous precipitation and application in SCR catalyst

    Institute of Scientific and Technical Information of China (English)

    姚杰; 仲兆平

    2016-01-01

    Ultrasonic treatment and hydrothermal method were applied in the traditional homogeneous precipitation for nano-TiO2 preparation, which was used as carrier material for the production of honeycomb selective catalytic reduction (SCR) catalyst. The influence rules of the two improved methods on characterization of TiO2 samples, denitration activity and mechanical strength of honeycomb SCR catalyst samples were mainly focused on. The results indicate that the specific surface area, particle size and uniformity of TiO2 samples are significantly improved by both of the ultrasonic and hydrothermal treatments compared with the traditional homogeneous precipitation. Also, the denitration activities of catalyst samples are enhanced by the two improved methods (the NOx reduction ratio increases from 88.89% to 95.45% by ultrasonic homogeneous precipitation process, and to 94.12% by hydrothermal homogeneous precipitation process). On the other hand, because of good spherical shape and high particle distribution of TiO2 sample from hydrothermal homogeneous precipitation process, the corresponding honeycomb catalyst samples get the best mechanical strength, which is even higher than that of the reference sample from commercial nano-TiO2. So, it is concluded that the hydrothermal homogeneous precipitation can be a feasible and effective preparation method of TiO2 carrier for the honeycomb SCR catalyst production.

  12. Activity Enhancement of Vanadium Catalysts with Ultrasonic Preparation Process for the Oxidation of Sulfur Dioxide

    Institute of Scientific and Technical Information of China (English)

    Zhenxing Chen; Honggui Li; Lingsen Wang

    2003-01-01

    The effect of ultrasonic cavitations on the activity of vanadium catalysts at low temperatures for the oxidation of sulfur dioxide, in which refined carbonized mother liquor had been added, was investigated.Twenty minutes were needed to produce obvious cavitations when the catalyst raw material was treated in the 50 W ultrasonic generator. However, only 10 minutes would be needed in a 150 W ultrasonic generator.The higher the temperature of the wet material, the less time was needed to produce cavitations, and the optimal temperature was 60 ℃. The water content in the wet material mainly affected the quantity of cavitations. Ls-8 catalyst was prepared using ultrasonic. Its activity for conversion of SO2 reached to 52.5% at 410 ℃ and 4.2% at 350 ℃. The differential thermal analyses indicate that both endothermic peaks and exothermic peaks noticeably shifted forward compared with Ls catalyst prepared without ultrasonic, and SEM results show a uniform pore size distribution for Ls-8 catalyst.

  13. Preparation of Molecular Sieve Catalyst and Application in the Catalytic Oxidation Treatment of Waste Water

    Institute of Scientific and Technical Information of China (English)

    WANG RongMin; XIE Xin; HE YuFeng; WANG YunPu; HE NaiPu; ZHANG ZhengLin; SONG PengFei; LIU WenJun

    2001-01-01

    @@ Citric acid is an important additive in foods, cosmetics, medicine and so on, but it discharges about 10 ton of factory effluent when 1 ton of citric acid is produced. The COD of the factory effluent is near 20000 mg/L. The treatment of citric acid factory effluent is a serious problem in environmental chemistry. It is found that molecular sieve support metal complexes have high catalytic activity in aerobic oxidation of alkene [1,2]. In this paper, a kind of molecular sieve catalyst was prepared. The catalyst was used for the treatment of citric acid factory effluent by method of catalytic oxygen oxidation.

  14. The curious case of zeolite-clay/binder interactions and their consequences for catalyst preparation

    OpenAIRE

    Whiting, Gareth T.; Chowdhury, Abhishek Dutta; Oord, R. van; Paalanen, Pasi; Weckhuysen, Bert M.

    2016-01-01

    Zeolite-based catalyst bodies are commonly employed in a range of important industrial processes. Depending on the binder and shaping method chosen, vast differences in the reactivity, selectivity and stability are obtained. Here, three highly complementary micro-spectroscopic techniques were employed to study zeolite ZSM-5-binder interactions in SiO2-, Al2O3-, SiO2 : Al2O3- (2 : 1 mix) and kaolinite-bound catalyst pellets. We establish how their preparation influences the zeolite-clay/binder...

  15. Preparation of highly active AlSBA-15-supported platinum catalyst for thiophene hydrodesulfurization

    OpenAIRE

    KANDA, Yasuharu; AIZAWA, Tomohiro; Kobayashi, Takao; UEMICHI, Yoshio; NAMBA, Seitaro; SUGIOKA, Masatoshi

    2007-01-01

    The catalytic activities of various noble metals (Pt, Pd, Rh, and Ru) supported on siliceous SBA-15 and Al-containing SBA-15 (AlSBA-15) for hydrodesulfurization (HDS) of thiophene at 350 C were investigated. AlSBA-15 was prepared by a grafting method using aluminum isopropoxide (Al(OC3H7)3) hexane solution. The HDS activity of Pt/AlSBA-15 catalyst was the highest among those of various supported noble metal catalysts, and this activity was higher than that of commercial CoMo/Al2O3 HDS catalys...

  16. Preparation and photocatalytic activity of B, Y co-doped nanosized TiO_2 catalyst

    Institute of Scientific and Technical Information of China (English)

    石中亮; 刘富梅; 姚淑华

    2010-01-01

    The catalysts of un-doped, single-doped and co-doped titanium dioxide (TiO2) powders were prepared by sol-gel method with Ti(OC4H9)4 as a raw material. The photocatalytic decomposition of phenol in aqueous solution under UV light was used as a probe reaction to evaluate their photocatalytic activities. The effects of B, Y co-doping on the crystallite sizes, crystal pattern, surface composition, and optical property of the catalyst were investigated by thermogravimetric differential thermal analysis, X-ray d...

  17. Preparation of microcapsule-supported palladium catalyst using SPG (Shirasu Porous Glass) emulsification technique

    Institute of Scientific and Technical Information of China (English)

    Ying Liu; Xiu Juan Feng; De Cai Bao; Kai Xiao Li; Ming Bao

    2010-01-01

    A new method for the preparation of microcapsule-supported palladium catalyst was described.The highly monodisperse crosslinked polystyrene microcapsules containing phosphine ligand were synthesized by the self-assembling of phase separated polymer(SaPSeP)method using diphenyl(4-vinylphenyl)phosphine and divinylbenzene as a monomer and crosslinking agent,respectively,and 2,2'-azobisisobutyronitrile(AIBN)as an initiator within the droplets of oil-in-water(O/W)emulsions,which were prepared by using the Shirasu Porous Glass(SPG)membrane emulsification technique.The prepared microcapsule-supported palladium catalyst exhibited high catalytic activity for Heck reaction and can be reused several times without loss of activity.

  18. Use of alumina spent catalyst and RFCC wastes from petroleum refinery to substitute bauxite in the preparation of Portland clinker.

    Science.gov (United States)

    Al-Dhamri, Hilal; Melghit, Khaled

    2010-07-15

    Bauxite was substituted with spent catalysts for clinker preparation. Three different clinkers were prepared: one with bauxite as a reference, one with spent alumina catalyst and another with reduced fluid cracking catalyst. Powder X-ray diffraction technique, thermal analysis and scanning electron microscope were used to characterize each clinker sample. Rietveld refinement shows that, in all clinkers prepared, alite was formed with hexagonal lattice and monoclinic belite has higher unit cell volume compared to the known beta-Ca(2)SiO(4). The physical and mechanical properties (specific area, setting time, heat of hydration, soundness and compressive strength) of the cement samples were studied. The results show that substitution of bauxite by spent catalysts gave close results in terms of chemical composition, physical and mechanical properties of the Portland clinker. Also it shows the spent catalysts do not affect the quality of the prepared cement. 2010 Elsevier B.V. All rights reserved.

  19. Use of alumina spent catalyst and RFCC wastes from petroleum refinery to substitute bauxite in the preparation of Portland clinker

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dhamri, Hilal [Chemistry Department, College of Science, Sultan Qaboos University, P.O. Box 36, Al-Khodh 123 (Oman); Melghit, Khaled, E-mail: melghit@squ.edu.om [Chemistry Department, College of Science, Sultan Qaboos University, P.O. Box 36, Al-Khodh 123 (Oman)

    2010-07-15

    Bauxite was substituted with spent catalysts for clinker preparation. Three different clinkers were prepared: one with bauxite as a reference, one with spent alumina catalyst and another with reduced fluid cracking catalyst. Powder X-ray diffraction technique, thermal analysis and scanning electron microscope were used to characterize each clinker sample. Rietveld refinement shows that, in all clinkers prepared, alite was formed with hexagonal lattice and monoclinic belite has higher unit cell volume compared to the known {beta}-Ca{sub 2}SiO{sub 4}. The physical and mechanical properties (specific area, setting time, heat of hydration, soundness and compressive strength) of the cement samples were studied. The results show that substitution of bauxite by spent catalysts gave close results in terms of chemical composition, physical and mechanical properties of the Portland clinker. Also it shows the spent catalysts do not affect the quality of the prepared cement.

  20. Preparation of Carbon Nanotubes from Methane on Ni/Cu/A1 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Renzhong Wei; Fengyi Li; Yan Ju

    2005-01-01

    A series of Ni/Cu/Al catalyst samples were prepared by the co-precipitation method. Carbon nanotubes with large inner diameters are successfully synthesized from methane on Ni/Cu/Al catalyst by adding sodium carbonate. The effects of the copper content and amounts of sodium carbonate on the morphology and microstructures of carbon nanotubes were investigated by CO adsorption and TEM technique. The experimental results showed that copper can influence both the catalytic activity and catalyst life. Best result was obtained when the copper content was 15%. Addition of sodium carbonate favors the formation of carbon nanotubes with large inner diameters. The growth mechanism of carbon nanotubes with large inner diameter is discussed.

  1. Removal and Conversion of Tar in Syngas from Woody Biomass Gasification for Power Utilization Using Catalytic Hydrocracking

    Directory of Open Access Journals (Sweden)

    Jiu Huang

    2011-08-01

    Full Text Available Biomass gasification has yet to obtain industrial acceptance. The high residual tar concentrations in syngas prevent any ambitious utilization. In this paper a novel gas purification technology based on catalytic hydrocracking is introduced, whereby most of the tarry components can be converted and removed. Pilot scale experiments were carried out with an updraft gasifier. The hydrocracking catalyst was palladium (Pd. The results show the dominant role of temperature and flow rate. At a constant flow rate of 20 Nm3/h and temperatures of 500 °C, 600 °C and 700 °C the tar conversion rates reached 44.9%, 78.1% and 92.3%, respectively. These results could be increased up to 98.6% and 99.3% by using an operating temperature of 700 °C and lower flow rates of 15 Nm3/h and 10 Nm3/h. The syngas quality after the purification process at 700 °C/10 Nm3/h is acceptable for inner combustion (IC gas engine utilization.

  2. Process for converting hydrocarbon oils and catalyst for use in such a process

    Energy Technology Data Exchange (ETDEWEB)

    Huizinga, T.; Schaper, H.; Hoek, A.

    1990-05-08

    This invention is directed at increasing the utilization of residual oil found in currently available crude oil feedstocks. The process of the invention is particularly suitable for hydrocracking, and comprises contacting a hydrocarbon oil in the presence of hydrogen with a hydrocracking catalyst. Suitable feedstocks include tar oils, vacuum gas oil, deasphalted oils, long and short residues, catalytically cracked cycle oils, thermally cracked gas oils, and synthetic crudes, or combinations of various such oils. Suitable process conditions comprise temperatures from 200 to 500{degree}C, hydrogen pressures up to 300 bar, space velocities of 0.1-10 kg feed per liter of catalyst per hour, and gas/feed ratios of 100-5000 Nl/kg feed. The catalyst used in the process comprises zeolite Y particles, with an average size in the range of 0.8 to 5.0 mm, and a unit cell size preferably from 24.19 to 24.35 {angstrom}. Preference is given to zeolite Y having a silica/alumina molar ratio of 8-15. The zeolite is combined with a hydrogenation component of a Group VI and/or VIII metal, preferably nickel and tungsten. Alumina is the preferred binder. The catalyst contains 60-85% zeolite and 15-40% binder, based on the total amount of zeolite and binder. The products of the process include gaseous material (in general C1-4 hydrocarbons), naphtha, and a middle distillate fraction. Experiments are described to illustrate the preparation of catalysts and the process of the invention. 1 tab.

  3. Using supported Au nanoparticles as starting material for preparing uniform Au/Pd bimetallic catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Villa, Alberto [Universita di Milano, Italy; Prati, Laura [Universita di Milano, Italy; Su, Dangshen [Fritz Haber Institute of the Max Planck Society, Berlin, Germany; Wang, Di [Fritz Haber Institute of the Max Planck Society, Berlin, Germany; Veith, Gabriel M [ORNL

    2010-01-01

    One of the best methods for producing bulk homogeneous (composition) supported bimetallic AuPd clusters involves the immobilization of a protected Au seed followed by the addition of Pd. This paper investigates the importance of this gold seed in controlling the resulting bimetallic AuPd clusters structures, sizes and catalytic activities by investigating three different gold seeds. Uniform Au-Pd alloy were obtained when a steric/electrostatic protecting group, poly(vinyl alcohol) (PVA), was used to form the gold clusters on activated carbon (AC). In contrast Au/AC precursors prepared using Au nanoparticles with only electrostatic stabilization (tetrakis(hydroxypropyl)phosphonium chloride (THPC)), or no stabilization (magnetron sputtering) produced inhomogeneous alloys and segregation of the gold and palladium. The uniform alloyed catalyst (Pd{at}Au{sub PVA}/AC) is the most active and selective catalyst, while the inhomogenous catalysts are less active and selective. Further study of the PVA protected Au clusters revealed that the amount of PVA used is also critical for the preparation of uniform alloyed catalyst, their stability, and their catalytic activity.

  4. Magnesium oxide prepared via metal-chitosan complexation method: Application as catalyst for transesterification of soybean oil and catalyst deactivation studies

    Science.gov (United States)

    Almerindo, Gizelle I.; Probst, Luiz F. D.; Campos, Carlos E. M.; de Almeida, Rusiene M.; Meneghetti, Simoni M. P.; Meneghetti, Mario R.; Clacens, Jean-Marc; Fajardo, Humberto V.

    2011-10-01

    A simple method to prepare magnesium oxide catalysts for biodiesel production by transesterification reaction of soybean oil with ethanol is proposed. The method was developed using a metal-chitosan complex. Compared to the commercial oxide, the proposed catalysts displayed higher surface area and basicity values, leading to higher yield in terms of fatty acid ethyl esters (biodiesel). The deactivation of the catalyst due to contact with CO2 and H2O present in the ambient air was verified. It was confirmed that the active catalytic site is a hydrogenocarbonate adsorption site.

  5. The mechanism of pyridine hydrogenolysis on molybdenum-containing catalysts : I. The monolayer MoO3-Al2O3 catalyst: Preparation and catalytic properties

    NARCIS (Netherlands)

    Sonnemans, J.; Mars, P.

    1973-01-01

    Preparation of a MoO3-Al2O3 catalyst with a monolayer of molybdenum oxide on the alumina was possible by adsorbing MoO2(OH)2 at 600°C from the gas phase. From the amounts of molybdenum adsorbed and the surface areas of the catalysts a characteristic value of 17Å2 was calculated for the area occupied

  6. Hydrogenolysis of Glycerol to Propylene Glycol on Nanosized Cu-Zn-Al Catalysts Prepared Using Microwave Process.

    Science.gov (United States)

    Kim, Dong Won; Ha, Sang Ho; Moon, Myung Jun; Lim, Kwon Taek; Ryu, Young Bok; Lee, Sun Do; Lee, Man Sig; Hong, Seong-Soo

    2015-01-01

    Cu-Zn-Al catalysts were prepared using microwave-assisted process and co-precipitation methods. The prepared catalysts were characterized by XRD, BET, XPS and TPD of ammonia and their catalytic activity for the hydrogenolysis of glycerol to propylene glycol was also examined. The XRD patterns of Cu/Zn/Al mixed catalysts show CuO and ZnO crystalline phase regardless of preparation method. The highest glycerol hydrogenolysis conversion is obtained with the catalyst having a Cu/Zn/Al ratio of 2:2:1. Hydrogen pre-reduction of catalysts significantly enhanced both glycerol conversions and selectivity to propylene glycol. The glycerol conversion increased with an increase of reaction temperature. However, the selectivity to propylene glycol increased with an increase of temperature, and then declined to 30.5% at 523 K.

  7. Preparation and characterization of Pd doped ceria–ZnO nanocomposite catalyst for methyl tert-butyl ether (MTBE) photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Seddigi, Zaki S. [Chemistry Department, Umm Al-Qura University, Makkah (Saudi Arabia); Bumajdad, Ali [Chemistry Department, Faculty of Science, Kuwait University (Kuwait); Ansari, Shahid P. [Chemistry Department, Umm Al-Qura University, Makkah (Saudi Arabia); Ahmed, Saleh A., E-mail: saleh_63@hotmail.com [Chemistry Department, Umm Al-Qura University, Makkah (Saudi Arabia); Danish, Ekram Y. [Chemistry Department, King Abdulaziz University, Jeddah (Saudi Arabia); Yarkandi, Naeema H. [Chemistry Department, Umm Al-Qura University, Makkah (Saudi Arabia); Ahmed, Shakeel [Center for Refining and Petrochemicals, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2014-01-15

    Highlights: • Novel Pd supported ceria–ZnO photocatalysts were prepared with different amounts of palladium. • The photocatalytic activity of these catalysts was evaluated for degradation of MTBE in water. • Near complete removal of MTBE was achieved using 1% Pd doped ceria–ZnO catalyst and UV irradiation. • Highest rate constant was obtained in case of 1% Pd doped ceria–ZnO catalyst. • Shape and size of pores are important factors for high photoactivity of catalyst. -- Abstract: A series of binary oxide catalysts (ceria–ZnO) were prepared and doped with different amounts of palladium in the range of 0.5%–1.5%. The prepared catalysts were characterized by SEM, TEM, XRD and XPS, as well as by N{sub 2} sorptiometry study. The XPS results confirmed the structure of the Pd CeO{sub 2−x}-ZnO. The photocatalytic activity of these catalysts was evaluated for degradation of MTBE in water. These photocatalyst efficiently degrade a 100 ppm aqueous solution of MTBE upon UV irradiation for 5 h in the presence of 100 mg of each of these photocatalysts. The removal of 99.6% of the MTBE was achieved with the ceria–ZnO catalyst doped with 1% Pd. In addition to the Pd loading, the N{sub 2} sorptiometry study introduced other factors that might affect the catalytic efficiency is the catalyst average pore sizes. The photoreaction was determined to be a first order reaction.

  8. THE INFLUENCE OF Pd IMPREGNATION INTO Al-MCM-41 ON THE CHARACTERS AND ACTIVITY FOR BIOGASOLINE PRODUCTION BY CATALYTIC HYDROCRACKING OF FAMEs FROM NYAMPLUNG SEED OIL (Calophyllum Inophyllum

    Directory of Open Access Journals (Sweden)

    Hendro Juwono

    2013-08-01

    Full Text Available Biogasoline have been synthesized through catalytic hydrocracking reaction against FAMEs compounds (fatty acid methyl esters obtained from the transesterification of Nyamplung seed oil. The performance of Al-MCM-41 and Pd/Al-MCM-41 as the catalytic hydrocracking was compared. In this research, the influence of Pd impregnation into Al-MCM-41 catalyst on the characters and catalytic activity has been evaluated. The characters determined were crystallinity by using X-Ray Diffractometer (XRD, Si/Al ratio by Inductively Coupled Plasma (ICP, the acidity by pyridine adsorption, the surface area and pore volume by surface area analyzer and the morphology by Scanning Electron Microscopy (SEM. Catalytic activity was examined for hydrocracking of free fatty acid methyl esters (FAMEs produced from the transesterification of Nyamplung seed oil, by Hydrogen flowing. The research result showed that impregnation of Pd into Al-MCM-41 has been successfully carried out, which did not destroy the structural morphology of the catalyst. It was also discovered that the Pd impregnation could increase Si/Al ratio and the acidity but it leads to decrease in the catalyst surface area and the volume. Furthermore, Pd impregnated Al-MCM-41 showed superior activity compared to Al-MCM-41 for FAMEs hydrocracking. The superiority was indicated by higher effectiveness and yields selectiveness, that were 100% hydrocarbon composed of C9-C18 that was dominated by C12 emerging the gasoline fraction, compared of that by the results used Al-MCM-41 catalyst that were 97% hydrocarbon consisted of C8-C20 with equal abundance.

  9. A New Humidity-Sensitive Material Based on PPBT Prepared with Palladium Complex Catalyst

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Soluble Poly(propargyl benzoate) (PPBT) with p -conjugated structure was synthesized using a novel bis(triphenylphosphine)-bisacetylide palladium complex catalyst [Pd(PPh3)2(Co CCH2OOCPh)2] (PPB). An interdigital gold electrode was covered by screen printing films of doped PPBT (DPPBT) to prepare a resistance-type humidity sensor, which exhibits electrical response towards relative humidity (RH%) variations in the range 11%-96%. PPBT shows promise as a new humidity-sensitive material.

  10. Hydrocarbon oxidation over catalysts prepared by the molecular layer deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Koltsov, S.I.; Smirnov, V.M.; Postnov, V.N.; Postnova, A.M.; Aleskovskii, V.B.

    1980-01-01

    By depositing consecutive uniform monolayers of phosphorus pentoxide and vanadium pentoxide on a large-surface-area (240 sq m/g) silica gel, active and selective catalysts for hydrocarbon oxidation were obtained. Thus, in piperylene oxidation by air at 330/sup 0/-430/sup 0/C and 2000-18,000/hr space velocity, a productive capacity of 220 g/l./hr with 41 mole % each maleic anhydride yield and selectivity was achieved over a SiO/sub 2/-P/sub 2/O/sub 5//P/sub 2/O/sub 5//V/sub 2/O/sub 5/ catalyst (120 sq cm/g surface area), compared with 80 g/l./hr for a P/sub 2/O/sub 5/-V/sub 2/O/sub 5/ catalyst prepared by impregnation. In benzene oxidation, maleic anhydride yields of 52 and 60% and selectivities of 63 and 79% were achieved over SiO/sub 2/-P/sub 2/O/sub 5//V/sub 2/O/sub 5/ and SiO/sub 2/-P/sub 2/O/sub 5//P/sub 2/O/sub 5//P/sub 2/O/sub 5//V/sub 2/O/sub 5/ catalysts, respectively, compared with a 6% yield and very low selectivity over the impregnated P/sub 2/O/sub 5/-V/sub 2/O/sub 5/ catalyst. The molecular-layer catalysts retained their total activity for 100 hr on stream and permitted to reduce the oxidation temperature by 50/sup 0/-70/sup 0/C.

  11. Iron Fischer-Tropsch Catalysts Prepared by Solvent-Deficient Precipitation (SDP: Effects of Washing, Promoter Addition Step, and Drying Temperature

    Directory of Open Access Journals (Sweden)

    Kyle M. Brunner

    2015-07-01

    Full Text Available A novel, solvent-deficient precipitation (SDP method for catalyst preparation in general and for preparation of iron FT catalysts in particular is reported. Eight catalysts using a 23 factorial design of experiments to identify the key preparation variables were prepared. The catalysts were characterized by electron microprobe, N2 adsorption, TEM, XRD, and ICP. Results show that the morphology of the catalysts, i.e., surface area, pore volume, pore size distribution, crystallite sizes, and promoter distribution are significantly influenced by (1 whether or not the precursor catalyst is washed, (2 the promoter addition step, and (3 the drying condition (temperature. Consequently, the activity, selectivity, and stability of the catalysts determined from fixed-bed testing are also affected by these three variables. Unwashed catalysts prepared by a one-step method and dried at 100 °C produced the most active catalysts for FT synthesis. The catalysts of this study prepared by SDP compared favorably in activity, productivity, and stability with Fe FT catalysts reported in the literature. It is believed that this facile SDP approach has promise for development of future FT catalysts, and also offers a potential alternate route for the preparation of other catalysts for various other applications.

  12. Preparation and application of zirconium sulfate supported on SAPO-34 molecular sieve as solid acid catalyst for esterification

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Dongyan, E-mail: xdy0156@sina.com; Ma, Hong; Cheng, Fei

    2014-05-01

    Graphical abstract: - Highlights: • SAPO-34 supported zirconium sulfate solid acid catalyst was prepared. • Esterification of acetic acid with ethanol can be catalyzed by ZS/SAPO-34. • The hydration of ZS is vital to the acidic property and catalytic performance. • The ZS/SAPO-34 catalyst treated at 200 °C shows good reusability. - Abstract: Zirconium sulfate (ZS) was supported on SAPO-34 molecular sieve by using an incipient wetness impregnation method with zirconium sulfate as the precursor. The as-prepared catalysts were used as solid acid catalyst for esterification reaction of acetic acid with ethanol. The influence of calcination temperature on the acidic property, catalytic activity, and reusability of ZS/SAPO-34 catalysts were mainly investigated. FT-IR, SEM, EDS and TG analysis have been carried out to demonstrate the characteristics of ZS/SAPO-34 catalysts. It was found that the 30 wt%ZS/SAPO-34 catalysts display the property of superacid irrespective of calcination temperature. The ZS/SAPO-34 catalyst treated at 200 °C can enhance the interaction between the supported ZS and SAPO-34 and keep the catalyst remaining substantially active after several reaction cycles. However, further increasing calcination temperature will cause the transfer of ZS from hydrate to anhydrous phase, and thus the decrease of activity.

  13. CO2 as a regulator for the controllable preparation of highly dispersed chitosan-supported Pd catalysts in ionic liquids.

    Science.gov (United States)

    Xue, Zhimin; Sun, Xiaofu; Li, Zhonghao; Mu, Tiancheng

    2015-07-11

    A controllable synthetic route has been developed for the preparation of chitosan supported Pd catalysts in an ionic liquid, 1-butyl-3-methylimidazolium acetate ([Bmim]OAc), by using compressed CO2 as the anti-solvent and regulator. It was found that the dispersion of Pd particles on chitosan and the catalytic activity of the as-prepared catalysts for the hydrogenation of styrene could be tuned by changing the pressure of CO2.

  14. Preparation and Performance of a Fixed Bed Catalyst for the Oxidation of Sodium Mercaptides

    Directory of Open Access Journals (Sweden)

    Heming Wang

    2014-07-01

    Full Text Available The activated-carbon supported cobalt pthalocyanine as a fixed bed catalyst (CoPc/C was prepared by impregnation method and its performance on the oxidation of sodium mercaptides in light oil sweetening was investigated. The FTIR, XRD, and SEM analysis indicated that the active component dispersed well on the carrier and the results of the TG analysis showed that CoPc/C has good thermostability. It was tested that the prepared catalyst has a high catalytic activity towards sodium mercaptides. The removal rate of n-C4H9SNa was up to 100 % and for t-C4H9SNa, was 87.5% at a reaction time of 30 min. With the reaction temperature raised from 20 °C to 60 °C at intervals of ten degrees, the oxidation rate increased obviously, especially in the first ten minutes. A kinetic model mainly related to the transfer process was supposed. The catalyst CoPc/C had a good anti-loss performance of the active component both in water and alkali liquor when used. © 2014 BCREC UNDIP. All rights reservedSubmitted: 20th June 2013; Revised: 1st March 2014; Accepted: 22nd March 2014[How to Cite: Heming, W., Xianshang, L., Lijun, Z., Yulu, Z., Daohong, X., (2014. Preparation and Performance of a Fixed Bed Catalyst for the Oxidation of Sodium Mercaptides. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (2: 87-92.(doi:10.9767/bcrec.9.2.5113.87-92][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.2.5113.87-92] 

  15. Effect of catalyst preparation on the yield of carbon nanotube growth

    Energy Technology Data Exchange (ETDEWEB)

    Escobar, Mariano, E-mail: mescobar@df.uba.a [Dep. Quimica Inorganica, Analitica y Quimica Fisica, FCEyN, UBA, Ciudad Universitaria (1428), Bs As (Argentina); LP and MC, Dep. Fisica, FCEyN, UBA (Argentina); Rubiolo, Gerardo [Unidad de Actividad Materiales, CNEA, Av Gral Paz 1499, San Martin (1650), Bs As (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Candal, Roberto [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Instituto de Fisico-quimica de Materiales, Ambiente y Energia (INQUIMAE), CONICET - UBA (Argentina); Goyanes, Silvia [LP and MC, Dep. Fisica, FCEyN, UBA (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)

    2009-10-01

    Multi-wall carbon nanotubes (MWCNTs) were synthesized by catalytic chemical vapor deposition (CVD) on catalytic iron nanoparticles dispersed in a silica matrix, prepared by sol gel method. In this contribution, variation of gelation condition on catalyst structure and its influence on the yield of carbon nanotubes growth was studied. The precursor utilized were tetraethyl-orthosilicate and iron nitrate. The sols were dried at two different temperatures in air (25 or 80 deg. C) and then treated at 450 deg. C for 10 h. The xerogels were introduced into the chamber and reduced in a hydrogen/nitrogen (10%v/v) atmosphere at 600 deg. C. MWCNTs were formed by deposition of carbon atoms from decomposition of acetylene at 700 deg. C. The system gelled at RT shows a yield of 100% respect to initial catalyst mass whereas the yield of that gelled at 80 deg. C was lower than 10%. Different crystalline phases are observed for both catalysts in each step of the process. Moreover, TPR analysis shows that iron oxide can be efficiently reduced to metallic iron only in the system gelled at room temperature. Carbon nanotubes display a diameter of about 25-40 nm and several micron lengths. The growth mechanism of MWCNTs is base growth mode for both catalysts.

  16. Preparation of nitric humic acid by catalytic oxidation from Guizhou coal with catalysts

    Institute of Scientific and Technical Information of China (English)

    Yang Zhiyuan; Gong Liang; Ran Pan

    2012-01-01

    Nitric humic acid was prepared by catalytic oxidation between nitric acid and Guizhou coal,with added catalysts.We investigated catalytic oxidation processes and the factors that affect the reactions.The effects of different catalysts,including NiSO4 support on active carbon (AC-NiSO4),NiSO4 support on silicon dioxide (SiO2-NiSO4),composites of SO42-/Fe2O3,Zr-iron and vanadium-iron composite were studied.As well.we investigated nitric humic acid yields and the chemical structure of products by element analysis,FT-IR and E4/E6 (an absorbance ratio at wavelengths of 465 and 665 nm of humic acid alkaline extraction solutions).The results show that the catalytic oxidation reaction with added catalysts can increase humic acid yields by 18.7%,16.36%,12.94%,5.61% and 8.59%,respectively.The highest yield of humic acid,i.e.,36.0%,was obtained with AC-NiSO4 as the catalyst.The amounts of C and H decreased with the amount of nitrogen.The increase in the E4/E6 ratio in catalytic oxidation of (Guizhou) coal shows that small molecular weights and high yields of nitric humic acid can be obtained by catalytic oxidation reactions.

  17. Preparation of high dispersion and high performance PtRu/CNTs catalyst by an organic colloid method

    Institute of Scientific and Technical Information of China (English)

    王宁卡特; 刘军民; 廖世军; V.Birss

    2006-01-01

    A high dispersion and high performance PtRu catalyst supported on carbon nanotubes was prepared by an organic colloid method. The particle size of the active components could be as small as 1.0 nm,the active surface area was about 466 m2/g(Pt). The catalytic activity toward anodic oxidation of methanol was about 3 ~ 4 times higher than that of Johnson Matthey PtRu/XC-72R catalyst. The single testing showed that the performance of the prepared catalyst was higher than that of the commercial one.

  18. Effective VTeO/SBA-15 Catalyst Prepared by Precursor Method for the Selective Oxidation of Propane to Acrolein

    Institute of Scientific and Technical Information of China (English)

    FENG Mao-ying; HUANG Chuan-jing; WENG Wei-zheng; WAN Hui-lin; XU Qin; ZHOU Zhao-hui

    2008-01-01

    Precursor decomposition was used for the preparation of VTeO/SBA-15 catalyst for the selective oxidation of propane to acrolein.The catalyst shows a better performance compared with those prepared by conventional impregnant method.A yield of 9.3% of acrolein was achieved with 2% V Ioadings at 500℃.XRD,N2-adsorption,H2-TPR,Py-IR and XPS measurements were used to unclose the relationship between the structure and performance of the catalyst.

  19. CuO/CeO{sub 2} catalysts prepared with different cerium supports for CO oxidation at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chi-Yuan [School of Public Health, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Chang, Wen-Chi [Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Wey, Ming-Yen, E-mail: mywey@dragon.nchu.edu.tw [Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China)

    2013-08-15

    The activity of a catalyst depends on the nature of its support, its active site, and its preparation method. This study aimed to employ various types of CeO{sub 2} supports such as commercial CeO{sub 2} and self-prepared CeO{sub 2} for the preparation of copper catalysts. The CuO/CeO{sub 2} catalysts were prepared using the polyol process and impregnation method. The catalysts were characterized using Brunauer–Emmett–Teller analysis, scanning electron microscopy, and X-ray analysis, and their catalytic activity for CO removal was evaluated in a microcatalytic reactor. The experimental results showed that the catalytic activity of the CuO/CeO{sub 2} catalysts with different calcination temperatures decreased in the following order: 500 °C > 300 °C > 700 °C. Compared to the impregnation method, the polyol process generated well-dispersed metal particles over the support and showed higher CO removal efficiency with low activation energy. Compared to CuO/CeO{sub 2} catalysts with commercial CeO{sub 2}, those with CeO{sub 2} that was self-prepared by pyrolysis had a large pore volume and good crystal structure of CeO{sub 2} and showed good performance. The catalytic activity for CO removal was in the following order: CuO/CeO{sub 2}-P (pyrolysis) > CuO/CeO{sub 2}-C (commercial) > CuO/CeO{sub 2}-D (deposition precipitation). CuO/CeO{sub 2}-P catalysts showed good activity even at low temperature. The CuO/CeO{sub 2}-P(300)-P-120 min catalyst was found to possess the good CO removal rate when the oxygen content was 6%, CO concentration was 500 ppm, catalyst weighed 1.0 g, pollutant gas velocity was 500 mL min{sup −1}, SV was 3.7 × 10{sup 4} h{sup −1}, and reaction temperature was 150 °C. - Highlights: • CuO/CeO{sub 2} catalysts were prepared using polyol and impregnation methods. • The supports of catalyst were self-prepared cerium oxide and commercial cerium oxide. • Pyrolysis and deposition precipitation methods were used for cerium preparation.

  20. One Step Preparation of Sulfonated Solid Catalyst and Its Effect in Esterification Reaction

    Institute of Scientific and Technical Information of China (English)

    康世民; 常杰; 范娟

    2014-01-01

    A carbon-based sulfonated catalyst was prepared by direct sulfonation and carbonization (in moderate conditions:200 °C, 12 h) of red liquor solids, a by-product of paper-making process. The prepared sulfonated cata-lyst (SC) had aromatic structure, composed of carbon enriched inner core, and oxygen-containing (SO3H, COOH, OH) groups enriched surface. The SO3H, COOH, OH groups amounted to 0.74 mmol·g-1, 0.78 mmol·g-1, 2.18 mmol·g-1, respectively. The fresh SC showed much higher catalytic activity than that of the traditional solid acid catalysts (strong-acid 732 cation exchange resin, hydrogen type zeolite socony mobile-five (HZSM-5), sulfated zir-conia) in esterification of oleic acid. SC was deactivated during the reactions, through the mechanisms of leaching of sulfonated species and formation of sulfonate esters. Two regeneration methods were developed, and the catalytic activity can be mostly regenerated by regeneration Method 1 and be fully regenerated by regeneration Method 2, respectively.

  1. The effect of preparation method on Pt/Nb{sub 2} O{sub 5} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Eleuterio, A.; Passos, F.B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Engenharia Quimica]. E-mail: fbpassos at telecom.uff.br; Aranda, D.A.G.; Schmal, M. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica. Dept, de Engenharia Quimica]. E-mail: donato@h2o.eq.ufrj.br; schmal@peq.coppe.ufrj.br; Santos, J.F.

    1998-06-01

    The use of the ion exchange method and the addition of lithium to Pt/NB{sub 2}O{sub 5} catalysts were investigated in this work, using techniques of temperature-programmed reduction, H{sub 2} and CO chemisorption, UV - Vis diffuse reflectance spectroscopy and the conversion of n-heptane as a catalytic test. The superficial precursor present after the calcination step is platinum oxide, as previously observed for Pt/Nb{sub 2} O{sub 5} catalysts prepared by the incipient wetness method. For some of the samples, auto reduction was observed during the calcination step, with the formation of low dispersion metallic platinum. The Pt/Nb{sub 5}O{sub 5} catalysts prepared by ion exchange showed a high yield of olefins, as compared to aromatics, in the conversion of n-heptane. However, a high yield of hydrogenolysis products was also observed. For some of the lithium-containing samples, there was a suppression of dehydrogenation and aromatization reactions, with an increase in central C-C bond hydrogenolysis. (author)

  2. Preparation and characterization of ultrafine Fe-Cu-based catalysts for CO hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Yunlai Su; Yingli Wang; Zhongmin Liu

    2008-01-01

    The ultrafine particles of a new style Fe-Cu-based catalysts for CO hydrogenation were prepared by impregnating the organic sol of Fe(OH)3 and Cu(OH)2 onto the activated Al2O3, in which the organic sol of Fe(OH)3 and Cu(OH)2 were pre-pared in the microemulsion of dodecylbenzenesulfonic acid sodium(S)/n-butanol(A)/toluene(O)/water with V(A)/V(O) = 0.25 and W(A)/W(S)=1.50. This catalyst was characterized by particle size analysis, XRD and TG. The results of particle size analysis showed that Fe(OH)3 particles with a mean size of 17.1 nm and Cu(OH)2 particles with an average size of 6.65 μm were obtained. TG analysis and XRD patterns suggested that 673 K is the optimal calcination temperature. CO hydrogenation produced C+2 OH with a high selectivity above 58 wt% by using the ultrafine particles as catalyst, and the total alcohol yield of 0.250 g·ml-1·h-1 was obtained when the contents of Al2O3 and K were 88.61 wt% and 1.60 wt%, respectively.

  3. Highly Active Non-PGM Catalysts Prepared from Metal Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Heather M. Barkholtz

    2015-06-01

    Full Text Available Finding inexpensive alternatives to platinum group metals (PGMs is essential for reducing the cost of proton exchange membrane fuel cells (PEMFCs. Numerous materials have been investigated as potential replacements of Pt, of which the transition metal and nitrogen-doped carbon composites (TM/Nx/C prepared from iron doped zeolitic imidazolate frameworks (ZIFs are among the most active ones in catalyzing the oxygen reduction reaction based on recent studies. In this report, we demonstrate that the catalytic activity of ZIF-based TM/Nx/C composites can be substantially improved through optimization of synthesis and post-treatment processing conditions. Ultimately, oxygen reduction reaction (ORR electrocatalytic activity must be demonstrated in membrane-electrode assemblies (MEAs of fuel cells. The process of preparing MEAs using ZIF-based non-PGM electrocatalysts involves many additional factors which may influence the overall catalytic activity at the fuel cell level. Evaluation of parameters such as catalyst loading and perfluorosulfonic acid ionomer to catalyst ratio were optimized. Our overall efforts to optimize both the catalyst and MEA construction process have yielded impressive ORR activity when tested in a fuel cell system.

  4. Sheer加氢裂化技术——第一代Sheer加氢裂化技术开发%Sheer hydrocracking Process——Development of first-generation Sheer hydrocracking technologies

    Institute of Scientific and Technical Information of China (English)

    李立权; 陈崇刚

    2013-01-01

    Sheer加氢裂化技术是一项能量高效利用的综合技术,包括正常操作停运反应加热炉的加氢裂化专利技术、高温高压逆流传热技术、新型反应器内构件技术、微旋流分离技术、非直接接触在线防垢和除垢技术以及硫化态催化剂新型开工技术.第一代Sheer加氢裂化技术以某加氢裂化装置为基准的计算结果表明,能量转换和传输环节降低能耗2.2%~3.5%;能量利用环节降低能耗0.28%~0.39%;能量回收环节降低能耗7.0% ~ 19.6%.集成开发的第一代Sheer加氢裂化技术可使装置能耗降低9.48%~ 23.49%,SO2和CO2排放均降低9.48%~23.49%,装置工程投资减少6.32%~ 12.80%,实现装置低能耗、低投资、长周期运行.%Sheer hydrocracking process is a high-efficiency energy-saving process, which includes patented hydrocracking reactor furnace technology with no open fire, HT and HP counter-current heat transfer technology , state-of-art reactor internals technology, micro-swirl separation technology, non-direct-contact fouling prevention technology and new start-up technology for sulfided catalysts. The calculation results of first-generation Sheer hydrocracking process based upon a hydrocracking unit show that, the energy consumption in heat exchange and heat transfer is reduced by 2.2% -3.5%; the energy requirement in energy utilization is lowered by 0.28% ~0.39% ; the energy consumption in energy recovery is decreased by 7.0% ~ 19. 6%. The application of 1 st-generation Sheer hydrocracking process can reduce unit energy consumption by 9. 48% ~ 23.48% , lower SO2 and CO2 emissions by 9.48% -23, 48% and saves 6. 32% ~ 12. 8% project investment. The unit can be constructed with lower investment and operated reliably at low energy consumption.

  5. Synthesis and Electrochemical Evaluation of Carbon Supported Pt-Co Bimetallic Catalysts Prepared by Electroless Deposition and Modified Charge Enhanced Dry Impregnation

    OpenAIRE

    John Meynard M. Tengco; Bahareh Alsadat Tavakoli Mehrabadi; Yunya Zhang; Akkarat Wongkaew; John R. Regalbuto; Weidner, John W.; John R. Monnier

    2016-01-01

    Carbon-supported bimetallic Pt-Co cathode catalysts have been previously identified as higher activity alternatives to conventional Pt/C catalysts for fuel cells. In this work, a series of Pt-Co/C catalysts were synthesized using electroless deposition (ED) of Pt on a Co/C catalyst prepared by modified charge enhanced dry impregnation. X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM) characterization of the base catalyst showed highly dispersed particles. A basic E...

  6. Preparation of Molecular Sieve Catalyst and Application in the Catalytic Oxidation Treatment of Waste Water

    Institute of Scientific and Technical Information of China (English)

    WANG; RongMin

    2001-01-01

    Citric acid is an important additive in foods, cosmetics, medicine and so on, but it discharges about 10 ton of factory effluent when 1 ton of citric acid is produced. The COD of the factory effluent is near 20000 mg/L. The treatment of citric acid factory effluent is a serious problem in environmental chemistry.  It is found that molecular sieve support metal complexes have high catalytic activity in aerobic oxidation of alkene [1,2]. In this paper, a kind of molecular sieve catalyst was prepared. The catalyst was used for the treatment of citric acid factory effluent by method of catalytic oxygen oxidation.  ……

  7. Preparation and Electrocatalytic Characteristics of PdW/C Catalyst for Ethanol Oxidation

    Directory of Open Access Journals (Sweden)

    Qi Liu

    2015-06-01

    Full Text Available A series of PdW alloy supported on Vulcan XC-72 Carbon (PdW/C with total 20 wt. % as electrocatalyst are prepared for ethanol oxidation by an ethylene glycol assisted method. Transmission electron microscopy (TEM characterization shows that PdW nanoparticles with an average size of 3.6 nm are well dispersed on the surface of Vulcan XC-72 Carbon. It is found that the catalytic activity and stability of the PdW/C catalysts are strongly dependent on Pd/W ratios, an optimal Pd/W composition at 1/1 ratio revealed the highest catalytic activity toward ethanol oxidation, which is much better than commercial Pd/C catalysts.

  8. Preparation of hierarchical mesoporous Zn/HZSM-5 catalyst and its application in MTG reaction

    Institute of Scientific and Technical Information of China (English)

    Youming Ni; Aiming Sun; Xiaoling Wu; Guoliang Hai; Jianglin Hu; Tao Li; Guangxing Li

    2011-01-01

    The hierarchical mesoporous Zn/ZSM-5 zeolite catalyst was prepared by NaOH treatment and Zn impregnation, and its application in the conversion of methanol to gasoline (MTG) was studied. N2 adsorption-desorption results showed that the mesopores with sizes of 2-20 nm in HZ5/0.3AT was formed by 0.3 M NaOH alkali treatment. The zeolite samples after modification were also characterized by XRF, AAS,XRD, SEM and NH3-TPD methods. Zn impregnated catalyst Zn/HZ5/0.3AT exhibited dramatic improvements in catalytic lifetime and liquid hydrocarbons yield. The selectivity of aromatic hydrocarbons was also improved after Zn impregnation. It is suggested that the mesopores of Zn/HZ5/0.3AT enhanced the synergetic effect of Zn species and acid sites and the capability to coke tolerance, which were confirmed by the results of catalytic test and TGA analysis, respectively.

  9. Methanol Reforming over Cobalt Catalysts Prepared from Fumarate Precursors: TPD Investigation

    Directory of Open Access Journals (Sweden)

    Eftichia Papadopoulou

    2016-02-01

    Full Text Available Temperature-programmed desorption (TPD was employed to investigate adsorption characteristics of CH3OH, H2O, H2, CO2 and CO on cobalt-manganese oxide catalysts prepared through mixed Co-Mn fumarate precursors either by pyrolysis or oxidation and oxidation/reduction pretreatment. Pyrolysis temperature and Co/Mn ratio were the variable synthesis parameters. Adsorption of methanol, water and CO2 was carried out at room temperature. Adsorption of H2 and H2O was carried out at 25 and 300 °C. Adsorption of CO was carried out at 25 and 150 °C. The goal of the work was to gain insight on the observed differences in the performance of the aforementioned catalysts in methanol steam reforming. TPD results indicated that activity differences are mostly related to variation in the number density of active sites, which are able to adsorb and decompose methanol.

  10. Fischer-Tropsch Synthesis over Iron Manganese Catalysts: Effect of Preparation and Operating Conditions on Catalyst Performance

    Directory of Open Access Journals (Sweden)

    Ali A. Mirzaei

    2009-01-01

    molar basis which is the most active catalyst for the conversion of synthesis gas to light olefins. The effects of different promoters and supports with loading of optimum support on the catalytic performance of catalysts are also studied. It was found that the catalyst containing 50%Fe/50%Mn/5 wt.%Al2O3 is an optimum-modified catalyst. The catalytic performance of optimal catalyst has been studied in operation conditions such as a range of reaction temperatures, H2/CO molar feed ratios and a range of total pressures. Characterization of both precursors and calcined catalysts is carried out by powder X-ray diffraction (XRD, scanning electron microscopy (SEM, BET specific surface area and thermal analysis methods such as TGA and DSC.

  11. Preparation of Ag/C catalysts for the O{sub 2} electrode by the Ag(I) SCRM

    Energy Technology Data Exchange (ETDEWEB)

    Han Jiajun, E-mail: hanjj20032000@yahoo.com.cn [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Li Ning; Liu Deli [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)

    2009-06-15

    Ag/C catalysts with different Ag particle-size distribution were prepared by Ag(I) single crystal reduction method (Ag(I) SCRM) and physically characterized. Their electrochemical performances were investigated by using Ag/C as O{sub 2} reduction catalysts in alkaline electrolyte. The results showed that the electrocatalytic activity of Ag/C catalysts prepared by the Ag(I) SCRM was significantly enhanced compared with that of Ag/C catalysts prepared by Ag{sub 2}O reduction method (Ag{sub 2}O RM) under the same content of Ag. The cyclic voltammetry indicate that the larger Ag particles are favourable to the four-electron reduction of O{sub 2}, the finer Ag particles are favourable to the two-electron reduction of O{sub 2}; the overpotential of four-electron reduction is higher, the overpotential of two-electron reduction is lower.

  12. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANO-PARTICLE MIXED ALCOHOL CATALYSTS

    Energy Technology Data Exchange (ETDEWEB)

    Seetala V. Naidu; Upali Siriwardane

    2005-01-14

    We have developed effective nanoparticle incorporated heterogeneous F-T catalysts starting with the synthesis of Fe, Co, Cu nanoparticles using Fe(acac){sub 3}, Co(acac){sub 2}, and Cu(acac){sub 2} precursors and incorporating the nanoparticles into alumina sol-gel to yield higher alkanes production. SEM/EDX, XRD, BET, VSM and SQUID experimental techniques were used to characterize the catalysts, and GC/MS were used for catalytic product analysis. The nanoparticle oxide method gave the highest metal loading. In case of mixed metals it seems that Co or Cu interferes and reduces Fe metal loading. The XRD pattern for nanoparticle mixed metal oxides show alloy formation between cobalt and iron, and between copper and iron in sol-gel prepared alumina granules. The alloy formation is also supported by DTA and VMS data. The magnetization studies were used to estimate the catalyst activity in pre- and post-catalysts. A lower limit of {approx}40% for the reduction efficiency was obtained due to hydrogenation at 450 C for 4 hrs. About 85% of the catalyst has become inactive after 25 hrs of catalytic reaction, probably by forming carbides of Fe and Co. The low temperature (300 K to 4.2 K) SQUID magnetometer results indicate a superparamagnetic character of metal nanoparticles with a wide size distribution of < 20 nm nanoparticles. We have developed an efficient and economical procedure for analyzing the F-T products using low cost GC-TCD system with hydrogen as a carrier gas. Two GC columns DC 200/500 and Supelco Carboxen-1000 column were tested for the separation of higher alkanes and the non-condensable gases. The Co/Fe on alumina sol-gel catalyst showed the highest yield for methane among Fe, Co, Cu, Co/Fe, Cu/Co, Fe/Cu. The optimization of CO/H{sub 2} ratio indicated that 1:1 ratio gave more alkanes distribution in F-T process with Co/Fe (6% each) impregnated on alumina mesoporous catalyst.

  13. Cracking vegetable oil from Callophylluminnophyllum L. seeds to bio-gasoline by Ni-Mo/Al2O3 and Ni-Mo/Zeolite as micro-porous catalysts

    Science.gov (United States)

    Savitri, Effendi, R.; Tursiloadi, S.

    2016-02-01

    Natural minerals such as zeolite are local natural resources in the various regions in Indonesia. Studies on the application of natural mineral currently carried out by national research institutions, among others, as a filler, bleaching agent, or dehydration agent. However, not many studies that utilize these natural minerals as green catalysts material which has high performance for biomass conversion processes and ready to be applied directly by the bio-fuel industry. The trend movement of green and sustainable chemistry research that designing environmentally friendly chemical processes from renewable raw materials to produce innovative products derived biomass for bio-fuel. Callophylluminnophyllum L. seeds can be used as raw material for bio-energy because of its high oil content. Fatty acid and triglyceride compounds from this oil can be cracked into bio-gasoline, which does not contain oxygen in the hydrocarbon structure. Bio-gasoline commonly is referred to as drop-in biofuel because it can be directly used as a substitute fuel. This paper focused on the preparation and formulation of the catalyst NiMo/H-Zeolite and Ni-Mo/Al2O3 which were used in hydro-cracking process of oil from Callophylluminnophyllum L. seeds to produce bio-gasoline. The catalysts were analyzed using XRD, BET and IR-adsorbed pyridine method. The results of hydro-cracking products mostly were paraffin (C10-C19) straight chain, with 59.5 % peak area based on GC-MS analysis.

  14. Monolitni katalizatori i reaktori: osnovne značajke, priprava i primjena (Monolith catalysts and reactors: preparation and applications

    Directory of Open Access Journals (Sweden)

    Tomašić, V.

    2004-12-01

    used in the preparation of monolithic catalysts are described. Several commercial applications of monolithic catalysts are presented. New applications and the associated technical challenges for the monolithic catalyst and reactors are discussed as well.

  15. Preparation of immobilized coating Fenton-like catalyst for high efficient degradation of phenol.

    Science.gov (United States)

    Wang, Jiankang; Yao, Zhongping; Wang, Yajing; Xia, Qixing; Chu, Huiya; Jiang, Zhaohua

    2017-03-06

    In this study, solid acid amorphous Fe3O4/SiO2 ceramic coating decorated with sulfur on Q235 carbon steel as Fenton-like catalyst for phenol degradation was successfully prepared by plasma electrolytic oxidation (PEO) in silicate electrolyte containing Na2S2O8 as sulfur source. The surface morphology and phase composition were characterized by SEM, EDS, XRD and XPS analyses. NH3-TPD was used to evaluate surface acidity of PEO coating. The results indicated that sulfur decorated amorphous Fe3O4/SiO2 ceramic coatings with porous structure and higher acid strength had the similar pore size and the surface became more and more uneven with the increase of Na2S2O8 in the silicate electrolyte. The Fenton-like catalytic activity of sulfur decorated PEO coatings was also evaluated. In contrast to negligible catalytic activity of sulfur undecorated PEO coating, catalytic activity of sulfur decorated PEO coating was excellent and PEO coating prepared with 3.0 g Na2S2O8 had the highest catalytic activity which could degrade 99% of phenol within 8 min under circumneutral pH. The outstanding performance of sulfur decorated PEO coating was attributed to strong acidic microenvironment and more Fe(2+) on the surface. The strong acid sites played a key factor in determining catalytic activity of catalyst. In conclusion, rapid phenol removal under circumneutral pH and easier separation endowed it potential application in wastewater treatment. In addition, this strategy of preparing immobilized solid acid coating could provide guidance for designing Fenton-like catalyst with excellent catalytic activity and easier separation.

  16. Effects of preparation variables of supported-cobalt catalysts on the selective hydrogenation of. alpha. ,. beta. -unsaturated aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Nitta, Yuriko; Hiramatsu, Yoshifumi; Imanaka, Toshinobu (Osaka Univ., Toyonaka (Japan))

    1990-11-01

    The effects of starting salts, supports, added amount of Na{sub 2}CO{sub 3}, and other precipitation variables on catalytic properties of supported cobalt catalysts were studied for the hydrogenation of cinnamaldehyde and crotonaldehyde by using TGA, XRD, and XPS. The catalysts prepared from cobalt chloride always exhibited high selectivities to unsaturated alcohols irrespective of the support employed. The amount of surface chlorine remaining after H{sub 2}-reduction of the Co/SiO{sub 2} precursors prepared from cobalt chloride decreased with increasing amount of Na{sub 2}CO{sub 3} added as the precipitant, and both activity and selectivity reached maxima at around Cl/Co = 0.2 in the catalyst surface. The enhanced selectivity of the catalyst prepared from cobalt chloride was explained by the effects of residual chlorine both in the H{sub 2}-reduction stage and in the reaction stage; the former leads to a favorable crystallite size distribution (CDS) of cobalt and the latter depresses the hydrogenation of C{double bond}C double bond. The difference in activities and selectivities of various supported catalysts prepared from cobalt nitrate was discussed based on the difference in the strength of metal-support interaction which leads to different CDSs of cobalt in theses catalysts.

  17. Radiolytically prepared Ni-Pd sols as catalysts for water photoreduction

    Energy Technology Data Exchange (ETDEWEB)

    Amouyal, E.; Georgopoulos, M.; Delcourt, M.O. (Paris-11 Univ., 91 - Orsay (FR). Lab. de Physico-Chimie des Rayonnements)

    1989-07-01

    Ni-Pd sols containing 10% Pd, prepared via radiolytic reduction, display a catalytic activity notably enhanced, compared to pure nickel sols, towards the water photoreduction to hydrogen. The test system is Ru(bipy){sub 3}{sup 2+}/methylviologen/N-phenylglycine: a favourable pH effect is shown at pH 2.5. Hydrogen evolution rate is not far from the optimal values obtained with platinum sols in acidic medium. These Ni-Pd aggregates are the first example of an aqueous colloid metal catalyst being improved by alloying effect.

  18. Preparation of catalyst for a polymer electrolyte fuel cell using a novel spherical carbon support

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, Mika; Okubo, Atsuhiko; Kobayashi, Yoshio [Department of Biomolecular Functional Engineering, Faculty of Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Yamamoto, Shun [Material and Biological Sciences, Graduate School of Science and Engineering, Faculty of Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Kikuchi, Mayuko; Nishitani-Gamo, Mikka [Department of Applied Chemistry, Faculty of Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585 (Japan); Uno, Katsuhiro [Department of Media and Telecommunications Engineering, Faculty of Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Ando, Toshihiro [National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2010-09-15

    In this study, the support Pt catalyst was supported by a novel spherical carbon using a convenient technique. Two different preparation methods utilizing a nanocolloidal solution method without heat treatment were developed (methods 1 and 2). The scanning electron microscope (SEM) and transmission electron microscope (TEM) observations showed that the Pt nanoparticles (particle size) were supported, with higher dispersion being achieved with method 2 than method 1. The peak of the Pt metal was confirmed from the X-ray diffraction (XRD) measurement. Based on the inductively coupled plasma mass spectrometry (ICP-MS) measurements, Pt loading was 19.5 wt.% in method 1 and approximately 50 wt.% in method 2. The Pt specific surface area of the Pt/novel spherical carbon catalyst calculated from the cyclic voltammetry (CV) measurement result was larger than that of the commercially available Pt/Ketjen catalyst. These results indicated that the Pt nanoparticles were supported in high dispersion without heat treatment using novel spherical carbon as a carbon support. (author)

  19. Preparation and characterization of Pd/C catalyst obtained in NH 3-mediated polyol process

    Science.gov (United States)

    Li, Huanqiao; Sun, Gongquan; Jiang, Qian; Zhu, Mingyuan; Sun, Shiguo; Xin, Qin

    Vulcan XC-72R carbon supported Pd nanoparticles was obtained in a NH 3-mediated polyol process without any protective agent and characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM) techniques. The added NH 3 species is found to have a strong complex ability to Pd, which not only avoids the formation of Pd hydroxide precipitate resulted from Pd hydrolysis, but also restrains the further complete reduction of Pd. Temperature-programmed reduction equipped with a mass spectrometry (TPR-MS) is employed to study the reductive behavior of unreduced Pd complex in Pd/C catalyst and the results show that the post-treatment in a reductive atmosphere at higher temperature is needed to ensure the complete reduction of Pd. XRD patterns show the heat-treated Pd/C sample in a reductive atmosphere has a face centered cubic crystal structure and TEM image indicates that the dispersion of Pd nanoparticles on the carbon support is uniform and in a narrow particle size range. Thermodynamic data analysis is carried out to elucidate the possible reaction pathway for the preparation of Pd/C catalyst in this process. The obtained Pd/C catalyst shows high activity to formic acid oxidation and high selectivity to oxygen reduction reaction (ORR) with the presence of methanol.

  20. Catalytic ozonation of sulfamethazine antibiotics using Ce0.1Fe0.9OOH: Catalyst preparation and performance.

    Science.gov (United States)

    Bai, Zhiyong; Yang, Qi; Wang, Jianlong

    2016-10-01

    Iron oxyhydroxides (FeOOH) are common crystalline forms of iron which play an important role in catalysis through a series of reduction-oxidation reactions. In this paper, Ce substituted goethite (Ce0.1Fe0.9OOH) was prepared by isomorphous substitution method, characterized by XRD, SEM, TEM-EDS, FTIR, and used for the catalytic ozonation of sulfamethazine (SMT). The results showed that the catalyst can significantly enhance the mineralization of SMT, and more than 42.1% SMT were mineralized in the presence of the catalyst, which is 1.74 times higher than ozonation alone. Moreover, with addition of catalyst, more ozone was dissolved into solution. The solution pH decreased due to small-molecule organic acids formation. The catalytic activity decreased slightly during the repeated batch experiments, due to the corrosion of the catalyst and the adsorption of the residual intermediates on the catalyst surface.

  1. Preparation and characterization of biomass carbon-based solid acid catalyst for the esterification of oleic acid with methanol.

    Science.gov (United States)

    Liu, Tiantian; Li, Zhilong; Li, Wei; Shi, Congjiao; Wang, Yun

    2013-04-01

    A solid acid catalyst, prepared by sulfonating carbonized corn straw, was proved to be an efficient and environmental benign catalyst for the esterification of oleic acid and methanol. Various synthetic parameters, such as carbonization temperature and time were systematically examined. It was found that the catalyst exhibited the highest acid density of 2.64 mmol/g by NaOH titration. A quantitative yield (98%) of ester was achieved, using the most active sulfonated catalyst at 333 K with a 7 wt.% catalyst/oleic acid ratio for 4h, at a 7:1 M ratio of methanol/oleic acid, while the commercial available Amberlyst-15 only gave 85% yield under the same reaction condition.

  2. Preparation, structural characterization of a novel egg-shell palladium sulfide catalyst and its application in selective reductive alkylation reaction

    Institute of Scientific and Technical Information of China (English)

    Qun Feng Zhang; Xiao Nian Li; Jia Chun Wu; Chang Su; Feng Feng; Qiao Ling Ding; Zhao Lian Yuan; Hong Wang; Lei Ma; Chun Shan Lu

    2012-01-01

    A novel egg-shell Pd-S catalyst with palladium metal as the core and a membrane of palladium sulfide as the surface has been prepared by sulphidizing Pd/C with H2S.This catalyst is effective for the reductive alkylation of p-amino diphenylamine (PADPA)and methylisobutyl ketone (MIBK) to afford N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenedianine (DBPPD) with conversion up to 99.42% and selectivity to 97.46%.Comparing with the other common palladium sulfide catalysts,the membrane of palladium sulfide on the surface and the core of palladium metal cause the Pd on the surface of the new catalyst in a lower sulfur coordination,which improves its activity.Our result indicates that this new egg-shell Pd-S/C is an efficient hydrogenation catalyst.

  3. Preparation and characterization of Ir/TiC catalyst for oxygen evolution

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Lirong [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Institute of Fuel Cell, Shanghai Jiao Tong University, Shanghai 200240 (China); Sui, Sheng [Institute of Fuel Cell, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhai, Yuchun [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China)

    2008-03-01

    Nano-sized titanium carbide (TiC) was employed as the support material for an iridium (Ir) electrocatalyst in a proton exchange membrane water electrolyser (PEMWE). The Ir/TiC electrocatalyst for the oxygen evolution reaction (OER) was prepared by chemical reduction and deposition with ultrasonic dispersion. The diameter of the Ir particles deposited on the TiC support is 10-40 nm. The Ir/TiC catalyst has a pore volume of 0.1425 cm{sup 3} g{sup -1}, which is about two times as high as that of the corresponding unsupported Ir. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis indicate that the Ir particles are nearly uniformly deposited on the surface of the TiC and exhibit remarkably fine variable crystallites and crystal lattice defects, which enhance the density of active sites and greatly improves the catalytic activity of the Ir/TiC catalyst. Cyclic voltammograms (CVs) reveal that the peak current density at 1.5 V versus SCE on the Ir/TiC is about nine times of that for the unsupported Ir black catalyst and potentiostatic analysis shows that the charge passed by the Ir/TiC after 600 s at 1.3 V versus SCE is about 15 times of that for the unsupported Ir catalyst. Electrochemical impedance spectroscopy (EIS) shows that the electrochemical polarization impedance of the Ir/TiC catalyst is about 50 {omega} cm{sup 2} per 0.02 mg as compared to 150 {omega} cm{sup 2} of the Ir black in the range of high frequency. The diffusion polarization impedances of the Ir/TiC form a semicircle and those of the Ir black are close to a straight line with a phase angle of 45 in the range of low frequency. Thus, the catalytic activity of the Ir/TiC for the OER is significantly higher than that of the unsupported Ir catalyst. The TiC support is chemically and electrochemically stable in the whole range of experimental potentials. (author)

  4. PREPARATION, CHARACTERIZATION AND CATALYTIC ACTIVITY TEST OF CoMo/ZnO CATALYST ON ETHANOL CONVERSION USING STEAM REFORMING METHOD

    Directory of Open Access Journals (Sweden)

    Wega Trisunaryanti

    2010-06-01

    Full Text Available Preparation, characterization and catalytic activity test of CoMo/ZnO catalyst for steam reforming of ethanol have been investigated. The catalysts preparation was carried out by impregnation of Co and/or Mo onto ZnO sample. Water excess was used in ethanol feed for steam reforming process under mol ratio of ethanol:water (1:10. Characterizations of catalysts were conducted by analysis of metal content using Atomic Absorption Spectroscopy (AAS. Determination of catalysts acidity was conducted by gravimetric method of adsorption of pyridine base. Catalytic activity test on ethanol conversion using steam reforming method was conducted in a semi-flow reactor system, at a temperature of 400 oC, for 1.5 h under N2 flow rate of 10 mL/min. Gas product was analyzed by gas chromatograph with TCD system. The results of catalysts characterizations showed that the impregnation of Co and/or Mo metals on ZnO sample increased its acidity and specific surface area. The content of Co in Co/ZnO and CoMo/ZnO catalysts was 1.14 and 0.49 wt%. The Mo content in CoMo/ZnO catalyst was 0.36 wt%. The catalytic activity test result on ethanol conversion showed that the ZnO, Co/ZnO, and CoMo/ZnO catalysts produced gas fraction of 16.73, 28.53, and 35.53 wt%, respectively. The coke production of ZnO, Co/ZnO, and CoMo/ZnO catalysts was 0.86, 0.24, and 0.08 wt%, respectively. The gas products consisted mainly of hydrogen.   Keywords: CoMo/ZnO catalyst, steam reforming, ethanol

  5. Preparation and Characterization of Anadara Granosa Shells and CaCO3 as Heterogeneous Catalyst for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Hadiyanto Hadiyanto

    2016-03-01

    Full Text Available Nowadays, the use of homogenous catalyst has been gradually reduced for its operational reason. The homogenous catalyst leads in difficulty of separation after the process completed and the life cycle is shorter. Therefore, most of researches are introducing heterogenous catalyst for its substitution. This research was aimed to evaluate the use of shell of Anadara granosa and CaCO3 as source of CaO based catalyst through impregnation method. The preparation of the catalyst was started by decomposition of shells and CaCO3 at temperature of 800 oC for 3 hours, followed by impregnation at 70 oC for 4 hours and then calcined at 800 oC for 2 hours. The CaCO3 based catalyst gained high yield of biodiesel (94% as compared to Anadara granoasa based catalyst (92%. The reusability study showed that these catalysts could be used until three times recycle with 40-60% yield of biodiesel. The CaO contents of catalyst decreased up to 90% after three times recycles. Copyright © 2016 BCREC GROUP. All rights reserved Received: 10th November 2015; Revised: 6th January 2016; Accepted: 6th January 2016 How to Cite: Hadiyanto, H., Lestari, S.P., Widayat, W. (2016. Preparation and Characterization of Anadara Granosa Shells and CaCO3 as Heterogeneous Catalyst for Biodiesel Production. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1: 21-26. (doi:10.9767/bcrec.11.1.402.21-26 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.402.21-26

  6. CO2 Reforming of CH4 over Nickel and Cobalt Catalysts Prepared from La-Based Perovskite Precursors

    Institute of Scientific and Technical Information of China (English)

    Jianjun Guo; Hui Lou; Yinghong Zhu; Xiaoming Zheng

    2003-01-01

    Four perovskite-type complex oxides (LaNiO3, La2NiO4, LaCoO3 and La2CoO4) were suc-cessfully prepared using two sol-gel methods, the Pechini method (PC) and the citric acid complexingmethod (CC). The catalysts were characterized by XRD and TPR. After reduction, the activity of thecatalysts in the CO2 reforming of methane was tested. Ni-based catalysts from La2NiO4 precursors werethe most active and stable catalyst after calcination above 850 ℃, which gave a methane conversion of0.025 mmol/(g@s) for those prepared by the PC method and 0.020 mmol/(g.s) by the CC method. Itwas proposed that the well-defined structure and lower reducibility is responsible for the unusual catalyticbehavior observed over the pre-reduced La2NiO4 catalyst.

  7. Steam reforming of ethanol for hydrogen production over Cu/Co-Mg-Al-based catalysts prepared by hydrotalcite route.

    Science.gov (United States)

    Homsi, Doris; Rached, Jihane Abou; Aouad, Samer; Gennequin, Cédric; Dahdah, Eliane; Estephane, Jane; Tidahy, Haingomalala Lucette; Aboukaïs, Antoine; Abi-Aad, Edmond

    2016-08-23

    The performances of different 5Cu/CoxMg6-xAl2 (x = 0; 2; 4; 6) catalysts prepared by the wet impregnation method were investigated in the ethanol steam-reforming reaction (ESR) at 450 °C during 4 h under a steam/ethanol ratio of 3 (S/E = 3). The best catalyst among the prepared solids was 5Cu/Co6Al2 as it showed a complete ethanol conversion and the highest hydrogen and carbon dioxide productivities. However, following 50 h of aging, the catalyst deactivated due to the formation of a high amount of carbonaceous products detected by differential scanning calorimetry/thermogravimetry. On the other hand, the 5Cu/Co2Mg4Al2 catalyst showed a much lower quantity of coke deposition with no deactivation due to the basic character conferred by the magnesium oxide phase.

  8. Selective hydrogenation of maleic anhydride over Pd/Al2O3 catalysts prepared via colloid deposition

    Indian Academy of Sciences (India)

    Hongjing Yuan; Chunlei Zhang; Weitao Huo; Chunli Ning; Yong Tang; Yi Zhang; Dequan Cong; Wenxiang Zhang; Jiahuan Luo; Su Li; Zhenlu Wang

    2014-01-01

    Pd/Al2O3 catalysts were prepared via colloid deposition and the performance of the catalysts was examined in the selective hydrogenation of maleic anhydride to succinic anhydride. When the reaction was carried on in a batch system with 1,4-dioxane as the solvent (353K and 1.0MPa), high conversion of maleic anhydride (>98%) and high selectivity (>99%) for succinic anhydride were observed after 5 h. The as-prepared Pd/Al2O3 catalyst also showed excellent performance in solvent-free system and fixed-bed systems. The maleic anhydride (MA) conversion was greater than 98%, and high selectivity (>99%) for succinic anhydride was obtained after 1600 h in a fixed bed reacter. The results showed that the activity of the Pd/Al2O3 catalysts was excellent due to its high active surface area.

  9. The construction of a hydrocracking installation at the Esso refinery in Rotterdam, Netherlands; Part 3. De bouw van een hydrocracker in het Esso raffinaderijcomplex in Rotterdam; Deel 3

    Energy Technology Data Exchange (ETDEWEB)

    Dijkgraaf, A.; Van Klooster, L.

    1993-03-01

    In three brief articles attention is paid to the title subject. The aim of the new hydrocracker is to produce sulfur-lean diesel oil. The first article highlights the composition of the project team, which consists of Esso employees, and the main contractor Fluor Daniels. Also important is to form a multi-disciplinary team of engineers. In the second article attention is paid to the importance of redundancy in the electric system of the hydrocracker. The chance of power supply failures is reduced considerably by means of a triple safety control with an error tolerance, which stops the hydrocracker when two of three meters report an error (Moonlight project). In this article the role of the process engineer in the design is highlighted. 1 fig.

  10. Catalytic activity vs. size correlation in platinum catalysts of PEM fuel cells prepared on carbon black by different methods

    Energy Technology Data Exchange (ETDEWEB)

    Nores-Pondal, F.J.; Granada, M.; Corti, H.R. [Departamento de Fisica de la Materia Condensada, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica (CNEA), General Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Vilella, I.M.J.; de Miguel, S.R.; Scelza, O.A. [Instituto de Investigaciones en Catalisis y Petroquimica (INCAPE), Facultad de Ingenieria Quimica (Universidad Nacional del Litoral) - CONICET, Santiago del Estero 2654, 3000 Santa Fe (Argentina); Troiani, H. [Departamento de Fisica, Centro Atomico Bariloche, Comision Nacional de Energia Atomica (CNEA), Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina)

    2009-10-15

    In this work nanoparticulated platinum catalysts have been prepared on carbon Vulcan XC-72 using three methods starting with chloroplatinic acid as a precursor: (i) formic acid as a reductor agent; (ii) impregnation method followed by reduction in hydrogen atmosphere at moderated temperature; and (iii) microwave-assisted reduction in ethylene glycol. The catalytic and size studies were also performed on a commercial Pt catalyst (E-Tek, De Nora). The characterization of the particle size and distribution was performed by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD). The characterizations of the catalytic and electrocatalytic properties of the catalysts were determined by studying the cyclohexane dehydrogenation reaction (CHD) and the behavior under cyclic voltammetry (CV) in sulfuric acid solutions. The measured electrochemical activity, along with the hydrogen chemisorption of the catalysts allows the estimation of effective particle sizes, which are much larger than those measured by TEM and XRD. The catalysts prepared by reduction with formic acid and ethylene glycol (microwave-assisted) show electrochemical activities very close to those of the commercial catalyst, and are almost insensitive to the Pt dispersion or Pt particle size. The chemical activity in CHD correlates well with the metallic dispersion determined by hydrogen chemisorption, indicating similar accesibility of H{sub 2} and cyclohexane to the catalyst surface. (author)

  11. Examining Rhodium Catalyst complexes for Use with Conducting Polymers Designed for Fuel Cells in Preparing Biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Carpio, M.M.; Kerr, J.B.

    2005-01-01

    Biosensing devices are important because they can detect, record, and transmit information regarding the presence of, or physiological changes in, different chemical or biological materials in the environment. The goal of this research is to prepare a biosensing device that is effective, quick, and low cost. This is done by examining which chemicals will work best when placed in a biosensor. The first study involved experimenting on a rhodium catalyst complexed with ligands such as bipyridine and imidazole. The rhodium catalyst is important because it is reduced from RhIII to RhI, forms a hydride by reaction with water and releases the hydride to react with nicotinamide adenine dinucleotide (NAD+) to selectively produce 1,4-NADH, the reduced form of NAD+. The second study looked at different types of ketones and enzymes for the enzyme-substrate reaction converting a ketone into an alcohol. Preliminary results showed that the rhodium complexed with bipyridine was able to carry out all the reactions, while the rhodium complexed with imidazole was not able to produce and release hydrides. In addition, the most effective ketone to use is benzylacetone with the enzyme alcohol dehydrogenase from baker’s yeast. Future work includes experimenting with bis-imidazole, which mimics the structure of bipyridine to see if it has the capability to reduce and if the reduction rate is comparable to the bipyridine complex. Once all testing is completed, the fastest catalysts will be combined with polymer membranes designed for fuel cells to prepare biosensing devices that can be used in a variety of applications including ones in the medical and environmental fields.

  12. Preparation of a Sulfonated Carbonaceous Material from Lignosulfonate and Its Usefulness as an Esterification Catalyst

    Directory of Open Access Journals (Sweden)

    Duckhee Lee

    2013-07-01

    Full Text Available Sulfonated carbonaceous material useful as a solid acid catalyst was prepared from lignosulfonate, a waste of the paper-making industry sulfite pulping process, and characterized by 13C-NMR, FT-IR, TGA, SEM and elemental analysis, etc. The sulfonic acid group density and total density of all acid groups in the sulfonated carbonaceous material was determined by titration to be 1.24 mmol/g and 5.90 mmol/g, respectively. Its catalytic activity in the esterification of cyclohexanecarboxylic acid with anhydrous ethanol was shown to be comparable to that of the ionic exchange resin Amberlyst-15, when they were used in the same amount. In the meantime, the sulfonic acid group was found to be leached out by 26%–29% after it was exposed to hot water (95 °C for 5 h. The catalytic usefulness of the prepared carbonaceous material was investigated by performing esterifications.

  13. Scalable preparation, characterization, and application of alkali-treated starch as a new organic base catalyst.

    Science.gov (United States)

    Tamaddon, Fatemeh; KazemiVarnamkhasti, MohammadTaghi

    2017-01-02

    Preparation, characterization, and application of alkali starch (AS) given by dry co-grinding of starch and alkali is described in this work. Grinding using a mortar (agate) and pestle or, more conveniently, a ball mill has been found to be satisfactory for the preparation of the AS. The AS products were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) and x-ray fluorescence (XRF) analyses. The base capacities of ASs were 4.25-4.45 mmol/g, respectively. AS is a low cost and easy to handle base catalyst that showed promising catalytic performance in the synthesis of a dihydroquinazoline-based antibacterial drug that involves tandem hydration or decarboxylative amidation, imination, and Aza-Michael reactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Biosyngas Fischer. Tropsch conversion by high Fe loaded supported catalysts prepared with ultrasound and microwave

    Energy Technology Data Exchange (ETDEWEB)

    Pirola, C.; Di Fronzo, A.; Boffito, D.C.; Bianchi, C. [Milano Univ. (Italy). Dipt. di Chimica; Di Michele, A. [Perugia Univ. (Italy). Dipt. di Fisica

    2012-07-01

    Catalysts with iron high loading of 30 wt%, promoted with K (2.0 wt%) and Cu (3.75 wt%), have been synthesized according to three different methods: (1) the traditional impregnation method (TR); (2) Ultrasound (US) assisted TR method; (3) Microwave (MW) assisted TR method. All the samples have been fully characterized by BET, ICP/OES, XRPD, TG-DTA, FT-IR, TPR, SEM and TEM and tested in a laboratory pilot plant for Fischer-Tropsch synthesis working at 220 C and 20 bar. The results of the catalysts characterization indicated that the morphology of the samples strongly depends on the method of preparation. The best FTS results in term of C{sub 2+} yield (41%) has been obtained using MW with a good value of the selectivity towards heavy hydrocarbons, while in term of CO conversion (58%), using US. The samples prepared with non-traditional methods show FTS better results, probably due to a more wide and uniform distribution of Fe in the medium during the synthesis phase. (orig.)

  15. Preferential Oxidation of CO in Excess Hydrogen over CuO-CeO2 Catalyst Prepared by Chelating Method

    Institute of Scientific and Technical Information of China (English)

    Zhigang Liu; Renxian Zhou; Xiaoming Zheng

    2007-01-01

    The CuO-CeO2 catalyst prepared by chelating method has a superior catalytic performance for the preferential oxidation of CO in rich hydrogen, compared with the CuO-CeO2 catalyst prepared by coprecipitation method. The CO conversions over these catalysts, at 120 ℃ and 120000 ml/(g.h) in the absence of CO2 and H2O, are 99.6% and 88.6%, respectively, and the selectivity of O2 over these catalysts is very close (i.e. 51.3% and 55.8%, respectively). The influence of certain factors such as hydrogen concentration, carbon monoxide concentration, H2O, O2/CO ratios, and space velocity on the catalytic performance of CuO-CeO2 catalyst prepared by chelating method is also studied. The results show that the addition of hydrogen and H2O has a negative effect on the catalytic performance of CuO-CeO2 catalyst,however, the variation of space velocity and the O2/CO ratio causes a comparatively slight influence.

  16. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANOPARTICLE MIXED ALCOHOL CATALYSTS

    Energy Technology Data Exchange (ETDEWEB)

    Seetala V. Naidu; Upali Siriwardane

    2005-05-24

    We have developed and streamlined the experimental systems: (a) Laser-induced solution deposition (LISD) photosynthesis, ball-milling, and chemical synthesis of Fe, Co, and Cu nanoparticle catalysts; (b) Sol-gel method for mesoporous {gamma}-Al{sub 2}O{sub 3}, SiO{sub 2}, hybrid alumina/silica granular supports; (c) Three sol-gel/oil-drop catalyst preparation methods to incorporate metal nanoparticles into mesoporous 1 mm granular supports; (d) Low-cost GC-TCD system with hydrogen as carrier gas for the determination of wide spectrum of alkanes produced during the F-T reactions; and (e) Gas-flow reactor and microchannel reactor for fast screening of catalysts. The LISD method could produce Co, Cu, and Fe (5 nm) nanoparticles, but in milligram quantities. We could produce nanoparticles in gram quantities using high-energy ball milling and chemical synthesis methods. Ball milling gave wide particle size distribution compared to the chemical synthesis method that gave almost uniform size ({approx}5 nm) particles. Metal nanoparticles Cu, Co, Fe, Cu/Co, Cu/Fe and Co/Fe were loaded (2-12 wt%) uniformly into {gamma}-Al{sub 2}O{sub 3}, SiO{sub 2}, or alumina/silica hybrid supports by combined sol-gel/oil-drop methods followed by calcination and hydrogenation steps, prior to syngas FT reaction studies. The properties of metal loaded {gamma}-Al{sub 2}O{sub 3} granules were compared for the two precursors: aluminum tri-sec-butoxide (ALTSB) and aluminum tri-iso-propoxide (ALTIP). The effect of solgel supports alumina, silica, and alumina/silica hybrid were examined on catalytic properties. Metal loading efficiencies for pure metal catalysts increased in the order Co, Cu and Fe in agreement with solubility of metal hydroxides. In case of mixed metals, Co and Cu seams to interfere and reduce Fe metal loading when metal nitrate solutions are used. The solubility differences of metal hydroxides would not allow precise control of metal loading. We have overcome this problem by

  17. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANOPARTICLE MIXED ALCOHOL CATALYSTS

    Energy Technology Data Exchange (ETDEWEB)

    Seetala V. Naidu; Upali Siriwardane

    2005-05-24

    We have developed and streamlined the experimental systems: (a) Laser-induced solution deposition (LISD) photosynthesis, ball-milling, and chemical synthesis of Fe, Co, and Cu nanoparticle catalysts; (b) Sol-gel method for mesoporous {gamma}-Al{sub 2}O{sub 3}, SiO{sub 2}, hybrid alumina/silica granular supports; (c) Three sol-gel/oil-drop catalyst preparation methods to incorporate metal nanoparticles into mesoporous 1 mm granular supports; (d) Low-cost GC-TCD system with hydrogen as carrier gas for the determination of wide spectrum of alkanes produced during the F-T reactions; and (e) Gas-flow reactor and microchannel reactor for fast screening of catalysts. The LISD method could produce Co, Cu, and Fe (5 nm) nanoparticles, but in milligram quantities. We could produce nanoparticles in gram quantities using high-energy ball milling and chemical synthesis methods. Ball milling gave wide particle size distribution compared to the chemical synthesis method that gave almost uniform size ({approx}5 nm) particles. Metal nanoparticles Cu, Co, Fe, Cu/Co, Cu/Fe and Co/Fe were loaded (2-12 wt%) uniformly into {gamma}-Al{sub 2}O{sub 3}, SiO{sub 2}, or alumina/silica hybrid supports by combined sol-gel/oil-drop methods followed by calcination and hydrogenation steps, prior to syngas FT reaction studies. The properties of metal loaded {gamma}-Al{sub 2}O{sub 3} granules were compared for the two precursors: aluminum tri-sec-butoxide (ALTSB) and aluminum tri-iso-propoxide (ALTIP). The effect of solgel supports alumina, silica, and alumina/silica hybrid were examined on catalytic properties. Metal loading efficiencies for pure metal catalysts increased in the order Co, Cu and Fe in agreement with solubility of metal hydroxides. In case of mixed metals, Co and Cu seams to interfere and reduce Fe metal loading when metal nitrate solutions are used. The solubility differences of metal hydroxides would not allow precise control of metal loading. We have overcome this problem by

  18. The effect of preparation factors on the structural and catalytic properties of mesoporous nanocrystalline iron-based catalysts for high temperature water gas shift reaction

    Energy Technology Data Exchange (ETDEWEB)

    Meshkani, Fereshteh; Rezaei, Mehran [University of Kashan, Kashan (Iran, Islamic Republic of)

    2015-07-15

    A systematic study was done on the effect of preparation factors on the structural and catalytic properties of mesoporous nanocrystalline iron-based catalysts in high temperature water gas shift reaction. The catalysts were prepared by coprecipitation method, and the effect of the main preparation factors (pH, refluxing temperature, refluxing time, concentration of the precursors solution) was studied. The catalysts were characterized by powder X-ray diffraction (XRD), N{sub 2} adsorption (BET), Temperature programmed reduction (TPR), transmission and scanning electron microscopies (TEM, SEM) techniques. The results revealed that the preparation factors affected the textural and catalytic properties of the Fe-Cr-Cu catalyst. The results showed that the prepared catalyst with the highest activity showed higher specific surface area compared to commercial catalyst and consequently exhibited higher activity in high temperature water gas shift reaction. The TEM analysis showed a nanostructure for this sample with crystallite size less than 20 nm.

  19. Mixed Oxide Supported MoO3 Catalyst: Preparation, Characterization and Activities in Nitration of o-xylene

    Directory of Open Access Journals (Sweden)

    S.M. Kemdeo

    2010-10-01

    Full Text Available TiO2-ZrO2 mixed oxide support was prepared and impregnated with 12 wt % MoO3 and calcined at various temperatures. The resultant catalyst systems were characterized by XRD, FT-IR, BET, SEM, NH3-TPD and pyridine adsorbed FT-IR methods to know the physico-chemical changes occurred in course of thermal treatment. Activities of these catalysts were tested by employing them in the nitration of o-xylene. Mostly, 500 oC calcined catalyst sample was found to be most active for nitration reaction. Catalyst calcined at higher temperatures showed the negative influence on o-xylene conversion and 4-nitro-o-xylene selectivity. Conversion can be correlated with the presence of strong Brönsted acid sites over the catalyst surface whereas change in selectivity was found attributed to the pore diameter of the catalyst. These catalysts also performed satisfactorily, when used for nitration of other aromatics. No use of corrosive sulfuric acid and efficient reusability of the catalyst make the process environmentally friendly and economic. ©2010 BCREC UNDIP. All rights reserved(Received: 9th February 2010, Revised: 5th March 2010; Accepted: 18th March 2010[How to Cite: S.M. Kemdeo, V.S. Sapkal, G.N. Chaudhari. (2010. Mixed Oxide Supported MoO3 Catalyst: Preparation, Characterization and Activities in Nitration of o-xylene. Bulletin of Chemical Reaction Engineering and Catalysis, 5(1: 39-49. doi:10.9767/bcrec.5.1.776.39-49][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.5.1.776.39-49 ]Cited by in: Taylor Francis |

  20. Mixed Oxide Supported MoO3 Catalyst: Preparation, Characterization and Activities in Nitration of o-xylene

    Directory of Open Access Journals (Sweden)

    S.M. Kemdeo

    2010-10-01

    Full Text Available TiO2-ZrO2 mixed oxide support was prepared and impregnated with 12 wt % MoO3 and calcined at various temperatures. The resultant catalyst systems were characterized by XRD, FT-IR, BET, SEM, NH3-TPD and pyridine adsorbed FT-IR methods to know the physico-chemical changes occurred in course of thermal treatment. Activities of these catalysts were tested by employing them in the nitration of o-xylene. Mostly, 500 oC calcined catalyst sample was found to be most active for nitration reaction. Catalyst calcined at higher temperatures showed the negative influence on o-xylene conversion and 4-nitro-o-xylene selectivity. Conversion can be correlated with the presence of strong Brönsted acid sites over the catalyst surface whereas change in selectivity was found attributed to the pore diameter of the catalyst. These catalysts also performed satisfactorily, when used for nitration of other aromatics. No use of corrosive sulfuric acid and efficient reusability of the catalyst make the process environmentally friendly and economic. ©2010 BCREC UNDIP. All rights reserved(Received: 9th February 2010, Revised: 5th March 2010; Accepted: 18th March 2010[How to Cite: S.M. Kemdeo, V.S. Sapkal, G.N. Chaudhari. (2010. Mixed Oxide Supported MoO3 Catalyst: Preparation, Characterization and Activities in Nitration of o-xylene. Bulletin of Chemical Reaction Engineering and Catalysis, 5(1: 39-49. doi:10.9767/bcrec.5.1.7126.39-49][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.5.1.7126.39-49 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/7126 ]Cited by in: Taylor Francis |

  1. Effect of preparation methods of aluminum emulsions on catalytic performance of copper-based catalysts for methanol synthesis from syngas

    Institute of Scientific and Technical Information of China (English)

    Lili Wang; Wen Ding; Yingwei Liu; Weiping Fang; Yiquan Yang

    2010-01-01

    Various Cu/ZnO/Al2O3 catalysts have been synthesized by different aluminum emulsions as aluminum sources and their performances for methanol synthesis from syngas have been investigated.The influences of preparation methods of aluminum emulsions on physicochemical and catalytic properties of catalysts were studied by XRD,SEM,XPS,N2 adsorption-desorption techniques and methanol synthesis from syngas.The preparation methods of aluminum emulsions were found to influence the catalytic activity,CuO crystallite size,surface area and Cu0 surface area and reduction process.The results show that the catalyst CN using the aluminum source prepared by addition the ammonia into the aluminum nitrate (NP) exhibited the best catalytic performance for methanol synthesis from syngas.

  2. Hydrogenation of Furfural to Furfuryl Alcohol over Co-B Amorphous Catalysts Prepared by Chemical Reduction in Variable Media

    Institute of Scientific and Technical Information of China (English)

    LI, Hui; CHAI, Wei-Mei; LUO, Hong-Shan; LI, He-Xing

    2006-01-01

    Five Co-B amorphous alloy catalysts were prepared by chemical reduction in different media, including pure water and pure ethanol as well as the mixture of ethanol and water with variable ethanol content. Their catalytic properties were evaluated using liquid phase furfural hydrogenation to furfuryl alcohol as the probe reaction. It was found that the reaction media had no significant influence on either the amorphous structure of the Co-B catalyst or the electronic interaction between metallic Co and alloying B. This could successfully account for the fact that all the as-prepared Co-B catalysts exhibited almost the same selectivity to furfuryl alcohol and the same activity per surface area ( RSH ), which could be considered as the intrinsic activity, since the nature of active sites remained unchanged. However, the activity per gram of Co ( RmH ) of the as-prepared Co-B catalysts increased rapidly when the ethanol content in the water-ethanol mixture used as the reaction medium for catalyst preparation increased. This could be attributed to the rapid increase in the surface area possibly owing to the presence of more oxidized boron species which could serve as a support for dispersing the Co-B amorphous alloy particles.

  3. A comparative study of differently prepared rare earths-modified ceria-supported gold catalysts for preferential oxidation of CO

    Energy Technology Data Exchange (ETDEWEB)

    Ilieva, L.; Ivanov, I.; Andreeva, D. [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Bl. 11, 1113 Sofia (Bulgaria); Pantaleo, G.; Venezia, A.M. [Istituto per lo Studio dei Materiali Nanostrutturati, CNR, I-90146 Palermo (Italy); Zanella, R. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico, Circuito Exterior S/N, Ciudad Universitaria, C.P. 04510, Mexico D. F. (Mexico)

    2009-08-15

    The preferential oxidation of CO in H{sub 2}-rich gas was studied over gold catalysts supported on ceria modified by rare earths (RE = La, Sm, Gd and Y). The ceria supports were prepared by mechanochemical activation or co-precipitation. The amount of RE{sub 2}O{sub 3} was 10 wt%. Gold (2 wt%) was added by the deposition-precipitation method. The samples were characterized using XRD, HRTEM, HAADF, TPR, and Raman spectroscopy. It was established that catalysts prepared by co-precipitation were more active than samples made by mechanochemical activation. A gold catalyst on yttrium-modified ceria, prepared by co-precipitation, exhibited the highest catalytic activity and selectivity, and high stability. No substantial differences in the size distribution and average size of the nanogold particles in the studied catalysts were observed. The main reason for the differences in PROX activity of these gold catalysts was searched into the role of the ceria supports, depending on the preparation method, and the nature of the modifier. (author)

  4. Influence of alcohol additives in the preparation of electrodeposited Pt-Ru catalysts on oxidized graphite cloths

    Energy Technology Data Exchange (ETDEWEB)

    Sieben, Juan Manuel, E-mail: jmsieben@uns.edu.ar [Instituto de Ingenieria Electroquimica y Corrosion, Universidad Nacional del Sur, B8000CPB Bahia Blanca (Argentina); Duarte, Marta M.E.; Mayer, Carlos E. [Instituto de Ingenieria Electroquimica y Corrosion, Universidad Nacional del Sur, B8000CPB Bahia Blanca (Argentina)

    2011-03-03

    Research highlights: > Pt-Ru catalysts were prepared by potential pulse electrodeposition from solutions containing EtOH or EG at pH 2 and 5. > The catalyst particle size, loading and dispersion were influenced by solution pH and alcohol addition. > The deposits prepared at pH 2 exhibited large irregular agglomerates while those prepared at pH 5 presented smaller globular particles. > Pt-Ru system prepared using EG at pH 5 exhibited the best performance for CH{sub 3}OH oxidation. - Abstract: Carbon supported Pt-Ru catalysts were prepared by multiple cycles of potentiostatic pulses from aqueous diluted chloroplatinic acid and ruthenium chloride solutions in the presence of ethanol or ethylene glycol at pH 2 and 5. SEM images showed that the metallic deposit prepared at pH 2 consisted of large irregular agglomerates, whereas smaller globular particles were obtained at pH 5. In addition, the average particle size was considerably decreased in the presence of the stabilizers. The supported Pt-Ru alloys were tested as catalysts for methanol electro-oxidation in acid media. Electrocatalytic activity measurements indicated that the most active electrode was obtained with ethylene glycol as additive at pH 5.

  5. Preparation of carbon alloy catalysts for polymer electrolyte fuel cells from nitrogen-containing rigid-rod polymers

    Energy Technology Data Exchange (ETDEWEB)

    Chokai, Masayuki [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Integrative Technology Research Institute, Teijin Ltd., 4-3-2, Asahigaoka, Hino, Tokyo 191-8512 (Japan); Taniguchi, Masataka; Shinoda, Tsuyoshi; Nabae, Yuta; Kuroki, Shigeki; Hayakawa, Teruaki; Kakimoto, Masa-aki [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Moriya, Shogo; Matsubayashi, Katsuyuki [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Business Development Division, Nisshinbo Holdings, Inc., 1-2-3, Onodai, Midori-ku, Chiba 267-0056 (Japan); Ozaki, Jun-ichi [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Department of Nanomaterial Systems, Graduate School of Engineering, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Miyata, Seizo [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); New Energy and Industrial Technology Development Organization, 1310 Omiya-cho, Saiwai-ku, Kawasaki, Kanagawa 212-8554 (Japan)

    2010-09-15

    Carbon alloy catalysts (CAC), non-precious metal catalysts for the oxygen reduction reaction (ORR), were prepared from various kinds of nitrogen-containing rigid-rod aromatic polymers, polyimides, polyamides and azoles, by carbonization at 900 C under nitrogen flow. The catalytic activity for ORR was evaluated by the onset potential, which was taken at a current density of -2 {mu}A cm{sup -2}. Carbonized polymers having high nitrogen content showed higher onset potential. In particular, CACs derived from azole (Az5) had an onset potential of 0.8 V, despite being was prepared without any metals. (author)

  6. Ni-Co/Mg-Al catalyst derived from hydrotalcite-like compound prepared by plasma for dry reforming of methane

    Institute of Scientific and Technical Information of China (English)

    Huali; Long; Yan; Xu; Xiaoqing; Zhang; Shijing; Hu; Shuyong; Shang; Yongxiang; Yin; Xiaoyan; Dai

    2013-01-01

    Ni-Co bimetallic catalysts with different Ni/Co content were derived from cold plasma jet decomposition and reduction of hydrotalcite-like compounds containing Ni,Co,Mg and Al,and their catalytic performance was investigated with dry reforming of methane.Experimental results showed that the hydrotalcite-like precursors could be completely decomposed and partly reduced by cold plasma jet,and the Nicontained catalysts exhibited much higher activity than the catalyst without Ni.Especially,the catalyst with Ni/Co ratio of 8/2 achieved not only the highest conversions of 80.3%and 69.3%for CH4 and CO2,respectively,but also the best stability in 100 h testing.The catalysts were characterized by XRD,XPS,TEM and N2 adsorption techniques,and the results showed that the better performance of the 8Ni2Co bimetallic catalyst was attributed to its higher metal dispersion,smaller metal particle size,as well as the interaction effect between Ni and Co,which were brought by the special catalyst preparation method.

  7. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANO-PARTICLE MIXED ALCOHOL CATALYSTS

    Energy Technology Data Exchange (ETDEWEB)

    Setala V. Naidu

    2003-01-01

    We have produced Co, Cu, and Fe nano-particles by Laser-induced solution deposition (LISD) as evidenced by TEM investigations. Sizes of the nano-particles created are in the order of 5 nm. The LISD system could generate nano-particles in quantities only in the order of a milligram. This may be mainly due to the limited photo induced reactions taking place on the surface of the solutions. We have designed experiments to use drop flow technique with LISD for nano-particle deposition on microreactors. Preliminary work has been done on Co and Fe thin film deposited microreactors. We are also investigating the catalytic properties of nano-particles of FeO and CoO prepared by ball milling and dispersed into sol-gel prepared alumina granules. We have continued our investigation of catalytic reactions of Cu, Co, Fe, Cu/Co, Cu/Fe and Co/Fe on alumina support. The metal oxides were first reduced with hydrogen and used for the conversion of CO/H{sub 2}. The surface area of the catalysts has been determined by nitrogen disorption. They are in the range of 200-300 m{sup 2}/g. Cu, Co, Fe, Co/Fe, Cu/Co and Cu/Fe showed increasing order of catalytic activity for CO/H{sub 2} conversion. We are also studying catalytic conversion rates for CO{sub 2}/H{sub 2} and CO/CO{sub 2}/H{sub 2} mixtures using these catalysts. Our investigations of Co and Fe thin film deposited microreactors showed higher CO/H{sub 2} conversion for Fe compared to Co. We have used vibrating sample magnetometer (VSM) to study the magnetic characteristics of as prepared, reduced, post-reaction catalysts. Comparative study of the ferromagnetic component of these samples gives the reduction efficiency and the changes in metal centers during catalytic reactions. Magnetic studies of post-reaction Co and Fe micro-reactors show that more carbide formation occurs for iron compared to cobalt.

  8. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANO-PARTICLE MIXED ALCOHOL CATALYSTS

    Energy Technology Data Exchange (ETDEWEB)

    Setala V. Naidu

    2003-01-01

    We have produced Co, Cu, and Fe nano-particles by Laser-induced solution deposition (LISD) as evidenced by TEM investigations. Sizes of the nano-particles created are in the order of 5 nm. The LISD system could generate nano-particles in quantities only in the order of a milligram. This may be mainly due to the limited photo induced reactions taking place on the surface of the solutions. We have designed experiments to use drop flow technique with LISD for nano-particle deposition on microreactors. Preliminary work has been done on Co and Fe thin film deposited microreactors. We are also investigating the catalytic properties of nano-particles of FeO and CoO prepared by ball milling and dispersed into sol-gel prepared alumina granules. We have continued our investigation of catalytic reactions of Cu, Co, Fe, Cu/Co, Cu/Fe and Co/Fe on alumina support. The metal oxides were first reduced with hydrogen and used for the conversion of CO/H{sub 2}. The surface area of the catalysts has been determined by nitrogen disorption. They are in the range of 200-300 m{sup 2}/g. Cu, Co, Fe, Co/Fe, Cu/Co and Cu/Fe showed increasing order of catalytic activity for CO/H{sub 2} conversion. We are also studying catalytic conversion rates for CO{sub 2}/H{sub 2} and CO/CO{sub 2}/H{sub 2} mixtures using these catalysts. Our investigations of Co and Fe thin film deposited microreactors showed higher CO/H{sub 2} conversion for Fe compared to Co. We have used vibrating sample magnetometer (VSM) to study the magnetic characteristics of as prepared, reduced, post-reaction catalysts. Comparative study of the ferromagnetic component of these samples gives the reduction efficiency and the changes in metal centers during catalytic reactions. Magnetic studies of post-reaction Co and Fe micro-reactors show that more carbide formation occurs for iron compared to cobalt.

  9. Continuous preparation of carbon-nanotube-supported platinum catalysts in a flow reactor directly heated by electric current

    Directory of Open Access Journals (Sweden)

    Alicja Schlange

    2011-10-01

    Full Text Available In this contribution we present for the first time a continuous process for the production of highly active Pt catalysts supported by carbon nanotubes by use of an electrically heated tubular reactor. The synthesized catalysts show a high degree of dispersion and narrow distributions of cluster sizes. In comparison to catalysts synthesized by the conventional oil-bath method a significantly higher electrocatalytic activity was reached, which can be attributed to the higher metal loading and smaller and more uniformly distributed Pt particles on the carbon support. Our approach introduces a simple, time-saving and cost-efficient method for fuel cell catalyst preparation in a flow reactor which could be used at a large scale.

  10. High efficient electrooxidation of formic acid at a novel Pt-indole composite catalyst prepared by electrochemical self-assembly

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Weiqiang [Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang 330013 (China); College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Wang, Chuanyi [Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Xu, Jingkun [Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang 330013 (China); Du, Yukou; Yang, Ping [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China)

    2011-02-01

    Self-assembly of Pt and indole into a novel composite catalyst on a glassy carbon electrode (GC) has been developed by a one-step electrodeposition in the presence of 3.0 mM H{sub 2}PtCl{sub 6} and 0.1 mM indole. Compared to Pt/GC and Pt/C, the novel Pt-indole composite catalyst exhibits higher catalytic activity and stronger poisoning tolerance for electrooxidation of formic acid. The adsorption strength of CO on the prepared Pt-indole composite catalyst is greatly weakened as demonstrated by CO stripping voltammograms. Because of its advantageous catalytic activity and poisoning tolerance, the novel Pt-indole composite catalyst is anticipated to find interesting applications in many important fields such as energy and catalysis. (author)

  11. Isobutane dehydrogenation over chromia alumina catalysts prepared from MIL-101:Insight into chromium species on activity and selectivity

    Institute of Scientific and Technical Information of China (English)

    Huahua Zhao; Huanling Song; Zhichao Miao; Lingjun Chou

    2014-01-01

    Various mesoporous chromia alumina catalysts were prepared by five different methods based on a metal-organic framework MIL-101 and their catalytic performances over isobutane dehydrogenation were investigated. The highly dispersed chromium species were produced on catalyst KCrAl-I1 with largest specific surface area of 198 m2·g−1 prepared with aluminium isopropoxide (Al(i-OC3H7)3) by ultrasonic im-pregnation method. However, the catalyst KCrAl-I2 synthesized by stirring impregnation possessed crystallineα-Cr2O3 phase, which was poorly dispersed. Two types of Cr-rich and Al-rich CrxAl2−xO3 solid solutions, designated as CrAl-I and CrAl-II phase, were formed over the catalysts KCrAl-I3 (prepared by Al(i-OC3H7)3 with nitric acid regulation), KCrAl-C4 (prepared by aluminium chloride hexahydrate) and KCrAl-N5 (prepared by aluminium nitrate nonahydrate). Catalytic evaluation results revealed that KCrAl-I1 exhibited the high isobutane con-version due to its highly dispersed chromium species. However, KCrAl-I3, KCrAl-C4 and KCrAl-N5 showed the higher isobutene selectivity (95.2%−96.4%) on account of the formation of chromia alumina solid solutions in the catalysts. Moreover, the solid solution over the chromia alumina catalysts could greatly suppress the coke formation.

  12. Preparation and characterization of hydrophobic platinum-doped carbon aerogel catalyst for hydrogen isotope separation

    Indian Academy of Sciences (India)

    M K Singh; R Singh; A Singh; D K Kohli; U Deshpande; P K Gupta

    2014-10-01

    We report preparation of hydrophobic platinum-doped carbon aerogel (PtCA) catalyst and its characterization for catalytic exchange reactions between hydrogen isotopes. The PtCA powder was synthesized by sol–gel polymerization method, mixed with colloidal PTFE solution, and coated on Dixon rings to obtain hydrophobic catalyst. The Pt cluster size in PtCA powder was observed to vary from 3 to 5 nm for a change in resorcinol to alkali molar ratio in synthesis solution from 20 to 200. Transmission electron microscopy of powder showed that the Pt clusters were uniformally dispersed and Pt0 metallic content estimated by X-ray photoelectron spectroscopy (XPS) was found to be of ∼ 70%. The catalytic activity was found to depend on Pt cluster size and was higher for smaller cluster size. For the smallest achieved Pt cluster size of 3 nm, catalytic activity of ∼ 0.8 m3 (STP) s-1 m-3 was obtained for hydrogen isotope exchange in atmospheric pressure conditions.

  13. Preparation and characterization of zirconium dioxide catalyst supports modified with rare earth elements

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Masakuni; Kimura, Mareo (Toyota Central Research and Development Labs., Inc., Aichi (Japan))

    1991-08-15

    ZrO{sub 2} catlyst supports modified with rare earth elements were prepared by coprecipitation from an aqueous solution of zirconium oxychloride and rare earth chlorides. The crystallization of amorphous hydrous ZrO{sub 2} was inhibited by doping with rare earths; the crystallization temperature was elevated as the amount and ionic radius of the rare earth modifiers was increased. Only modification using cerium had no effect on the crystallization process. The behavior of cerium was different from that of other rare earth elements with valency +3. A metastable cubic phase was formed for ZrO{sub 2} modified with 10 mol.% lanthanum, neodymium and samarium by heating at 600degC. X-ray diffraction and Raman data indicated that the metastable phase had large microstrain and short-range ordering similar to tetragonal symmetry. Rare earth modified ZrO{sub 2} showed a large surface area and good thermal stability as a catalyst support. The carbon monoxide oxidation activity of iron was enhanced by modification with neodymium of ZrO{sub 2} supports. The results suggest the effectiveness of rare earth modified ZrO{sub 2} as catalyst supports. (orig.).

  14. Ceria Prepared by Flame Spray Pyrolysis as an Efficient Catalyst for Oxidation of Diesel Soot

    DEFF Research Database (Denmark)

    Christensen, Jakob Munkholt; Deiana, Davide; Grunwaldt, Jan-Dierk

    2014-01-01

    Ceria has been prepared by flame spray pyrolysis and tested for activity in catalytic soot oxidation. In tight contact with soot the oxidation activity (measured in terms of the temperature of maximal oxidation rate, Tmax) of the flame made ceria is among the highest reported for CeO2. This can...... to a significant degree be ascribed to the large surface area achieved with the flame spray pyrolysis method. The importance of the inherent soot reactivity for the catalytic oxidation was studied using various soot samples, and the reactivity of the soot was found to have a significant impact, as the Tmax......-value for oxidation in tight contact with a catalyst scaled linearly with the Tmax-value in non-catalytic soot oxidation. The Tmax-value in non-catalytic soot oxidation was in turn observed to scale linearly with the H/C ratio of the carbonaceous materials....

  15. Preparation of Fischer-Tropsch catalysts from cobalt/iron hydrotalcites

    Energy Technology Data Exchange (ETDEWEB)

    Howard, B.H.; Boff, J.J.; Zarochak, M.F. [Pittsburgh Energy Technology Center, PA (United States)] [and others

    1995-12-31

    Compounds with the (hydrotalcites) have properties that make them attractive as precursors for Fischer-Tropsch catalysts. A series of single-phase hydrotalcites with cobalt/iron atom ratios ranging from 75/25 to 25/75 has been synthesized. Mixed cobalt/iron oxides have been prepared from these hydrotalcites by controlled thermal decomposition. Thermal decomposition at temperatures below 600 {degrees}C typically produced a single-phase mixed metal oxide with a spinel structure. The BET surface areas of the spinal samples have been found to be as high as about 150 m{sup 2}/g. Appropriate reducing pretreatments have been developed for several of these spinels and their activity, selectivity, and activity and selectivity maintenance have been examined at 13 MPa in a fixed-bed microreactor.

  16. Preparation of MgO supported platinum nanoparticle catalyst using toluene dispersed platinum sol

    Science.gov (United States)

    Seth, Jhumur; Nepak, Devadutta; Chaudhari, Vijay R.; Prasad, Bhagavatula L. V.

    2017-10-01

    An effective way of anchoring Pt nanoparticles on MgO using toluene dispersed platinum nanoparticles (Pt-NPs) as one of the ingredient is demonstrated. The usage of particles dispersed in toluene allows the retention of size and size distribution of preformed Pt-NPs even after deposition on MgO support with high active surface area, which is crucial for heterogeneous catalysis. The catalyst thus prepared, displayed selective hydrogenation of cinnamaldehyde to cinnamyl alcohol with high turn on frequency (TOF - 105 h-1) with respect to the total Pt content. We attribute this efficient catalytic performance to the uniform distribution and deposition of Pt on the active MgO support and its better accessible surface as evidenced by the cyclic-voltammetry results.

  17. Development of a Method for the Preparation of Ruthenium Indenylidene-Ether Olefin Metathesis Catalysts

    Science.gov (United States)

    Jimenez, Leonel R.; Tolentino, Daniel R.; Gallon, Benjamin J.; Schrodi, Yann

    2012-01-01

    The reactions between several derivatives of 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and different ruthenium starting materials [i.e., RuCl2(PPh3)3 and RuCl2(pcymene)(L), where L is tricyclohexylphosphine di-t-butylmethylphosphine, dicyclohexylphenylphosphine, triisobutylphosphine, triisopropylphosphine, or tri-npropylphosphine] are described. Several of these reactions allow for the easy, in-situ and atom-economic preparation of olefin metathesis catalysts. Organic precursor 1-(3,5-dimethoxyphenyl)-1-phenyl-prop-2-yn-1-ol led to the formation of active ruthenium indenylidene-ether complexes, while 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and 1-(3,5-dimethoxyphenyl)-1-methyl-prop-2-yn-1-ol did not. It was also found that a bulky and strong σ-donor phosphine ligand was required to impart good catalytic activity to the new ruthenium complexes. PMID:22580400

  18. An alternative preparation method for ion exchanged catalysts: Solid state redox reaction

    DEFF Research Database (Denmark)

    Schneider, E.; Hagen, A.; Grunwaldt, J.-D.

    2004-01-01

    A new method for modifying zeolites with zinc is proposed. The solid state redox reaction between metallic zinc and ZSM-5 zeolites with different Si/Al ratios was investigated by temperature programmed hydrogen evolution (TPHE), X-ray absorption near edge structure (XANES) and diffuse reflectance...... infrared Fourier transform spectroscopy (DRIFTS). The evolution of hydrogen was detected at temperatures above 620 K. The source of hydrogen was the solid state redox reaction of the metal with protons of the support. The samples exhibit catalytic activity in ethane aromatization indicating that zinc...... should be located at the same sites as in catalysts prepared by conventional methods. Combination of XANES and catalytic activity point to zinc being mainly present in tetrahedral geometry under reaction conditions....

  19. Process for the preparation of composite crystalline aluminium silicates and their use as catalyst (carrier)

    Energy Technology Data Exchange (ETDEWEB)

    Van Erp, W.A.; Huizinga, T.; Seelen-Kruijssen, J.

    1989-01-31

    A process is presented for the preparation of a composite crystalline aluminum silicate by maintaining an aqueous alkaline starting mixture comprising one or more silicon compounds, one or more aluminium compounds, one or more compounds of metals from Group Ia of the Periodic Table and organic nitrogen compounds at an elevated temperature, until composite crystalline aluminium silicate has formed. Subsequently, crystalline silicate is separated from the mother liquor, wherein the various compounds are present in the starting mixture in defined molar ratios. These silicates can be used as catalyst or catalyst carrier in dewaxing hydrocarbon oils, to which process this invention further relates. To be used in such a process, the alkali metal content of the composite silicates must be reduced to less than 0.1 wt%. If desired, the performance of the silicates can be improved by using them simultaneously as carrier for one or more catalytically active metals from Groups VIb, VIIb and VIII8 of the Periodic Table or compounds thereof. The hydrocarbon oils which are to be dewaxed are preferably selected from the group consisting of lubricating oils and transformer oils (in order to reduce their pour point), and kerosenes and gas oils (in order to reduce their freezing point). Additionally, this invention relates to hydrocarbon oils which have been dewaxed according to the process of the invention. Furthermore, the invention relates to molecular sieves which comprise a composite crystalline aluminum silicate prepared as hereinbefore described, and to the application of such molecular sieves in a process for separating hydrocarbons. 5 tabs.

  20. The curious case of zeolite-clay/binder interactions and their consequences for catalyst preparation.

    Science.gov (United States)

    Whiting, Gareth T; Chowdhury, Abhishek Dutta; Oord, Ramon; Paalanen, Pasi; Weckhuysen, Bert M

    2016-07-04

    Zeolite-based catalyst bodies are commonly employed in a range of important industrial processes. Depending on the binder and shaping method chosen, vast differences in the reactivity, selectivity and stability are obtained. Here, three highly complementary micro-spectroscopic techniques were employed to study zeolite ZSM-5-binder interactions in SiO2-, Al2O3-, SiO2 : Al2O3- (2 : 1 mix) and kaolinite-bound catalyst pellets. We establish how their preparation influences the zeolite-clay/binder interactions. Using thiophene as an acid-catalyzed staining reaction, light absorbing oligomers produced in each sample were followed. To our surprise, kaolinite decreased the overall reactivity of the sample due to the phase change of the binder, creating a hard impenetrable outer layer. Aluminum migration to the zeolite was observed when Al2O3 was selected as a binder, creating additional Brønsted acid sites, which favored the formation of ring-opened thiophene oligomers compared to the larger oligomer species produced when SiO2 was used as a binder. In the latter case, the interaction of the Si-OH groups in the binder with thiophene was revealed to have a large impact in creating such large oligomer species. Furthermore, the combination of a SiO2 : Al2O3 mix as a binder enhanced the reactivity, possibly due to the creation of additional Brønsted acid sites between the two binder components during pellet preparation. It is evident that, independent of the shaping method, the intimate contact between the zeolite and binder heavily impacts the reactivity and product selectivity, with the type of binder playing a vital role.

  1. Preparation and characterization of Cu-Ce-La mixed oxide as water-gas shift catalyst for fuel cells application

    Institute of Scientific and Technical Information of China (English)

    ZHI Keduan; LIU Quansheng; ZHAO Ruigang; HE Runxia; ZHANG Lifeng

    2008-01-01

    Cu-Ce-La mixed oxides were prepared by three precipitation methods (coprecipitation, homogeneous precipitation, and deposition precipitation) with variable precipitators and characterized using X-ray diffraction, BET, temperature-programmed reduction, and catalytic reaction for the water-gas shift. The Cu-Ce-La mixed oxide prepared by coprecipitation method with NaOH as precipitator presented the highest activity and thermal stability. Copper ion substituted quadrevalent ceria entered CeO2 (111) framework was in favor of activity and thermal stability of catalyst. The crystallinity of fresh catalysts increased with the reduction process. La3+ or Ce4+ substituted copper ion entered the CeO2 framework during reduction process. The coexistence of surface copper oxide (crystalline) and pure bulk crystalline copper oxide both contributed to the high activity and thermal stability of Cu-Ce-La mixes oxide catalyst.

  2. Impact of heating rate and solvent on Ni-based catalysts prepared by solution combustion method for syngas methanation

    Directory of Open Access Journals (Sweden)

    Zeng Yan

    2014-12-01

    Full Text Available Ni-Al2O3 catalysts prepared by solution combustion method for syngas methanation were enhanced by employing various heating rate and different solvent. The catalytic properties were tested in syngas methanation. The result indicates that both of heating rate and solvent remarkably affect Ni particle size, which is a key factor to the catalytic activity of Ni-Al2O3 catalysts for syngas methanation. Moreover, the relationship between Ni particle size and the production rate of methane per unit mass was correlated. The optimal Ni-Al2O3 catalyst prepared in ethanol at 2°C/min, achieves a maximum production rate of methane at the mean size of 20.8 nm.

  3. Catalyzed oxidative degradation of methyl orange over Au catalyst prepared by ionic liquid-polymer modified silica

    Science.gov (United States)

    Wang, Y.; Guo, J. S.

    2015-07-01

    A new type of hybrid material was prepared by grafting an ionic liquid monomer, 1-(p-vinylbenzyl)-3-methylimidazolium chloride, on the surface of the porous silica which was synthesized via sodium silicate hydrolysis. The as-synthesized products were characterized by scanning electron microscope, nitrogen physisorption experiment, thermogravimetric analysis and Fourier transform infrared spectra. A catalyst with Au was prepared using the hybrid material as carrier. The experimental results show that the catalyst exhibits a better catalytic effect of hydrogen peroxide on the degradation of methyl orange. The reason may be that the metal component of the catalyst facilitated the dissociation of hydrogen peroxide to produce abundant highly active free radicals which can rapidly ruin the structure of methyl orange molecules in water. Finally, a probable catalytic degradation mechanism based on diffusion was discussed.

  4. Influence of Preparation Method on the Metal Cluster Size of Platinum/ZSM-5 Catalysts as studied with EXAFS.

    NARCIS (Netherlands)

    Koningsberger, D.C.; Kampers, F.W.H.; Engelen, C.W.R.; Hooff, J.H.C. van

    1990-01-01

    The size of Pt particles introduced into the channels of ZSM-5 zeolite by two different preparation methods has been studied with EXAFS. ZSM-5 was loaded with 2 wt 5% Pt by ion exchange and by impregnation. By careful calcination of the catalysts the dispersion was maintained. The EXAFS measurements

  5. An iron molybdate catalyst for methanol to formaldehyde conversion prepared by a hydrothermal method and its characterization

    NARCIS (Netherlands)

    Beale, A.M.; Jacques, S.D.M.; Sacaliuc-Parvulescu, E.; O'Brien, M.G.; Barnes, P.; Weckhuysen, B.M.

    2009-01-01

    A one-step, low-temperature hydrothermal method has been successfully employed to prepare iron molybdate catalysts with Mo:Fe ratios ranging from 1.5:1 to 3.0:1. The resulting materials were characterized using a number of techniques including: XRD, Raman, N2 adsorption, SEM/EDX, DTA, EDXRD and comb

  6. Bismuth molybdate catalysts prepared by mild hydrothermal synthesis: Influence of pH on the selective oxidation of propylene

    DEFF Research Database (Denmark)

    Schuh, Kirsten; Kleist, Wolfgang; Høj, Martin

    2015-01-01

    A series of bismuth molybdate catalysts with relatively high surface area was prepared via mild hydrothermal synthesis. Variation of the pH value and Bi/Mo ratio during the synthesis allowed tuning of the crystalline Bi-Mo oxide phases, as determined by X-ray diffraction (XRD) and Raman spectrosc...

  7. Hydrogen production by ethanol steam reforming over Cu-Ni/SBA-15 supported catalysts prepared by direct synthesis and impregnation

    Energy Technology Data Exchange (ETDEWEB)

    Carrero, A.; Calles, J.A.; Vizcaino, A.J. [Department of Chemical and Environmental Technology, Rey Juan Carlos University, Escuela Superior de Ciencias Experimentales y Tecnologia (ESCET), c/Tulipan s/n, 28933 Mostoles (Spain)

    2007-07-31

    Cu-Ni/SBA-15 supported catalysts prepared by the incipient wetness impregnation method were tested in the ethanol steam reforming reaction for hydrogen production. The effect of reaction temperature and metal loading was studied in order to maximize the hydrogen selectivity and the CO{sub 2}/(CO + CO{sub 2}) molar ratio. The best catalytic performance was achieved at 600 C. Products distribution was the result of the combined effects of metal particles size, metal content and Ni/Cu ratio on the catalyst. In addition, two catalysts were prepared by the method of direct insertion of Ni and Cu in the initial stage of the SBA-15 synthesis. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), N{sub 2}- adsorption and inductively coupled plasma atomic emission spectroscopy (ICP-AES) results evidenced that SBA-15 materials with long range hexagonal ordering were successfully synthesized in the presence of copper and nickel salts with the (Cu + Ni) contents around 4-6 wt.%. However, lower hydrogen selectivity as well as ethanol and water conversions were obtained with catalysts prepared by direct synthesis in comparison with those prepared by incipient wetness impregnation method. Particularly, the best catalytic results were achieved with a sample impregnated with 2 and 7 wt.% of copper and nickel, respectively. (author)

  8. Preparation of Uniform Ni-B Amorphous Alloy Catalyst on CNTs and its Performance for Acetylene Selective Hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Chang Yuan HU; Feng Yi LI; Rong Bin ZHANG; Li HUA

    2006-01-01

    Uniform Ni-B amorphous alloys about 14 nm have been prepared on CNTs-A support,named Ni-B/CNTs-A. In comparison with the Ni-B/CNTs amorphous catalyst, Ni-B/CNTs-A showed higher nickel loading, determined by ICP and better catalytic activity and ethylene selectivity in the acetylene hydrogenation reaction.

  9. Reverse microemulsion prepared Ni–Pt catalysts for methane cracking to produce COx-free hydrogen

    KAUST Repository

    Zhou, Lu

    2017-09-08

    A monodispersed 15 nm Ni9Pt1 catalyst synthesized via a reverse microemulsion method, shows a lower activation energy than both Ni and Pt catalysts during the methane cracking reaction. Thanks to the synergic effect of Ni–Pt alloy, this catalyst presents a stable H2 formation rate at 700 °C, and forms carbon nanotubes, anchoring the catalyst particles on top.

  10. Study of the performance of vanadium based catalysts prepared by grafting in the oxidative dehydrogenation of propane

    Energy Technology Data Exchange (ETDEWEB)

    Santacesaria, E.; Carotenuto, G.; Tesser, R.; Di Serio, M. [Naples Univ. (Italy). Dept. of Chemistry

    2011-07-01

    The oxidative dehydrogenation (ODH) of propane has been investigated by using many different vanadia based catalysts, prepared by grafting technique and containing variable amounts of active phase supported on SiO{sub 2} previously coated, by grafting in three different steps, with multilayer of TiO{sub 2}. A depth catalytic screening, conducted in a temperature range of 400-600 C, at atmospheric pressure and in a range of residence time W/F=0.08-0.33 ghmol{sub -1}, has shown that the vanadium oxide catalysts on TiO{sub 2}-SiO{sub 2} support, prepared by grafting have good performances in the ODH of propane. In particular, a preliminary study has demonstrated that higher selectivities can be obtained employing catalysts having a well dispersed active phase that can be achieved with a V{sub 2}O{sub 5} content lower than 10%{sub w}t. It is well known that, in the case of redox catalysts, an increase of the selectivity can be achieved not only by using an adequate catalytic system but also via engineering routes like decoupling catalytic steps of reduction and re-oxidation. In fact it has been observed that by operating in dehydrogenating mode, on the same catalysts, a higher selectivity is obtained although the catalyst is poisoned by the formation of coke on the surface. As consequence of the results obtained in dehydrogenation, in this work has been explored the possibility to feed low amounts of oxygen, below the stoichiometric level with the aim to keep clean the surface from coke but maintaining high the selectivity, because, dehydrogenation reaction prevails. In this work, the behavior of catalysts containing different amounts of V2O5 has been studied in the propane-propene reaction by using different ratios C{sub 3}H{sub 8}/O{sub 2} included in the range 0-2. (orig.)

  11. Alumina-Supported Manganese Catalysts for Soot Combustion Prepared by Thermal Decomposition of KMnO4

    Directory of Open Access Journals (Sweden)

    Agustin Bueno-López

    2012-09-01

    Full Text Available Alumina-supported manganese catalysts with cryptomelane and/or birnessite structure have been prepared using a simple method based on the thermal decomposition of potassium permanganate. The samples have been characterized by XRD, FTIR, TGA, DSC, N2 adsorption at −196 °C, SEM, H2-TPR and XPS, and their catalytic activity for soot combustion has been tested and compared to that of a reference Pt/alumina catalyst. The thermal decomposition of alumina-supported KMnO4 yields a mixture of supported birnessite and potassium manganate which is the most effective, among those prepared, to lower the soot combustion temperature. However, this material is not useful for soot combustion because the accelerating effect is not based on a catalytic process but on the oxidation of soot by potassium manganate. A suitable soot combustion catalyst is obtained after potassium manganate is removed by water washing, yielding only the birnessite phase on the γ-Al2O3 support. This birnessite phase can be transformed into cryptomelane by calcination at 600 °C. These two samples, γ-Al2O3-supported birnessite and cryptomelane are suitable catalysts for soot combustion in NOx/O2 mixtures, as their catalytic activity is based on the NO2-assited mechanism, that is, both catalysts accelerate the oxidation of NO to NO2 and NO2 promotes soot oxidation. The soot combustion temperatures obtained with these birnessite/cryptomelane alumina-supported catalysts are similar to that obtained with the reference Pt/alumina catalyst.

  12. EFFECTS OF CATALYST MORPHOLOGY ON HYDROTREATING REACTIONS

    Directory of Open Access Journals (Sweden)

    TYE CHING THIAN

    2008-08-01

    Full Text Available Due to the new environmental regulations for fuel quality, refineries need to process cleaner fuel. This requires an improvement in performance of hydrotreating catalysts. Improvements in catalyst activity require knowledge of the relationships between catalyst morphology and activity. Molybdenum sulfide, the generally agreed catalysts that give the best performance in hydrocracking and hydrotreating was investigated for its morphology effects on hydrotreating reactions. Three types of MoS2 catalysts with different morphology were studied. They are crystalline MoS2, exfoliated MoS2 and MoS2 derived from a precursor, molybdenum naphthenate. Exfoliated MoS2 with minimal long range order, with much higher rim edges has shown relative higher hydrogenation activity. Generally, results of MoS2 catalyst activities in hydrogenation, hydrodesulfurization, hydrodenitrogenation and hydrideoxy¬gena¬tion are in agreement with the rim-edge model.

  13. Preparation and characterization of planar Ni–Au bimetallic model catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Fan, E-mail: fan.yang@chem.tamu.edu; Yao, Yunxi; Yan, Zhen; Min, Hlaing; Goodman, D. Wayne

    2013-10-15

    Ni–Au bimetallic model catalysts were prepared as thin films on Re(0 0 0 1) or Ru(0 0 0 1) single crystal substrates. Surface compositions and electronic structures of the Ni–Au thin films were characterized by low energy ion scattering spectroscopy and X-ray photoelectron spectroscopy, respectively. Surface alloys were prepared by annealing Ni–Au thin films from 500 to 800 K, resulting in substantial surface enrichment of Au. Annealing a Ni–Au thin film with a 1:1 bulk composition ratio at 700 K for 10 min resulted in a surface alloy with 84% (atomic concentration) of Au in the outermost surface layer. The surface atomic structure was investigated using CO as probe molecules, which exclusively adsorbs on the Ni atoms rather than on the Au atoms at room temperature. Polarization modulation infrared reflection absorption spectroscopy of CO adsorption on Ni–Au surface alloys showed that CO adsorption on two-fold bridge sites decreased and finally disappeared with an increase of Au surface concentration. The absence of Ni bridge site CO adsorption indicated that Ni atoms were isolated by Au atoms on Ni–Au alloyed surface.

  14. Effects of preparation methods of support on the properties of nickel catalyst for hydrogenation of m-dinitrobenzene

    Institute of Scientific and Technical Information of China (English)

    LIU Yingxin; WEI Zuojun; CHEN Jixiang; ZHANG Jiyan

    2007-01-01

    Using tetraethyl orthosilicate(TEOS) as the precursor of silica,the silica aerogel and xerogel,which were used as supports of nickel-based catalysts for liquid hydrogenation of m-dinitrobenzene to m-phenylenediamine,were prepared by the sol-gel method combined with supercritical drying(SCD)and conventional drying,respectively.Then,a series of nickel-based catalyst samples supported on these supports were prepared by the incipient wetness impregnation method with an aqueous solution of nickel nitrate as well as lanthanum nitrate as impregnation liquids.Based on the characterization results of nitrogen adsorption-desorption (BET),X-ray diffraction(XRD),temperature programmed reduction(TPR),temperature-programmed desorption of hydrogen(H2-TPD),and catalytic activity evaluation,the physico-chemical properties and catalytic performances of the catalysts were investigated.The results show that the nickel crystallites on the binary nickel catalyst using silica aerogel as support are of smaller particle size.However,compared with the sample supported on silica xerogel,the nickel catalyst supported on the silica aerogel exhibits lower activity and selectivity for the hydrogenation of m-dinitrobenzene because it has a lesser amount of active sites and weaker absorption ability to reactants caused by sintering of the nickel crystallites.The addition of promoter La2O3 could increase the activity and selectivity of the catalysts.Among all the nickel-based catalyst samples prepared,the La2O3 promoted ternary nickel-based catalyst supported on silica xerogel exhibits the highest activity and selectivity for the hydrogenation of m-dinitrobenzene to m-phenylenediamine,which could be attributed to its highest active surfacc area and appropriate absorption strength to reactants.Over this promising catalyst,me conversion of m-dinitrobenzene and the yield of m-phenylenediamine could reach 97.0%and 93.1%,respectively,under proper reaction conditions of hydrogen pressure 2.6 MPa

  15. Non-Precious Metal Catalysts Prepared By Zeolitic Imidazolate Frameworks: The Ligand Influence to Morphology and Performance

    Energy Technology Data Exchange (ETDEWEB)

    Barkholtz, H. M.; Chong, L.; Kaiser, Z. B.; Liu, D. -J

    2016-08-01

    A new, “one-pot” synthesis to produce highly active non-PGM electrocatalysts for PEM fuel cells was previously developed by pyrolyzing Fe doped zeolitic imidazolate framework (ZIF) materials prepared by solid-state interaction. Excellent catalytic oxygen reduction reaction (ORR) activities were found through rotating ring-disk electrode (RRDE) and single fuel cell tests. In this study, we compared the ORR activities and structural properties of two catalysts derived from ZIFs containing imidazole and methyl imidazole ligands, respectively. Our results indicate that alkyl group substitution in the imidazolate ligand has a profound effect on the final catalyst performance.

  16. Comparative study of CuO-CeO{sub 2} catalysts prepared by wet impregnation and deposition-precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Gurbani, A.; Ayastuy, J.L.; Gonzalez-Marcos, M.P.; Gutierrez-Ortiz, M.A. [Departamento de Ingenieria Quimica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Bilbao 48080 (Spain); Unidad Asociada ' ' Tecnologias Quimicas para la Sostenibilidad Ambiental' ' , CSIC-UPV/EHU (Spain); Herrero, J.E.; Guil, J.M. [Instituto de Quimica Fisica ' ' Rocasolano' ' - CSIC, Madrid 28006 (Spain); Unidad Asociada ' ' Tecnologias Quimicas para la Sostenibilidad Ambiental' ' , CSIC-UPV/EHU (Spain)

    2009-01-15

    Two different preparation methods are used to synthesize wt. 7% CuO-CeO{sub 2} catalysts: a conventional wet impregnation method, and a deposition-precipitation (DP) method using Na{sub 2}CO{sub 3} as precipitating agent. Both samples are characterized by a series of techniques. CuO-CeO{sub 2} (Cu-Ce) prepared by DP shows a lower capacity to release the lattice oxygen to form CO{sub 2}. From CO-TPR results, it is demonstrated that this catalyst is not able to reduce copper clusters at low temperatures. Also, CO-TPD shows no CO{sub 2} formation. The activity results confirm the worse performance of Cu-Ce prepared by DP especially when oxygen is not in excess (PROX reaction with stoichometric oxygen). A copper particle size which is too small could create a stronger metal-support interaction, with lower Cu-Ce interface to react. (author)

  17. Ziegler-Natta catalyst for polypropylene and polyethylene nanocomposites preparation; Catalisador Ziegler-Natta para a obtencao de nanocompositos de polipropileno e polietileno

    Energy Technology Data Exchange (ETDEWEB)

    Silvino, Alexandre C.; Dias, Marcos L.; Bezerra, Ana Beatriz F., E-mail: mldias@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Profa. Eloisa Mano; Jaconis, Selma; Gambetta, Rossano; Fernandes, Rodrigo M. [Quattor Petroquimica S.A., Maua, SP (Brazil)

    2009-07-01

    Polypropylene and polyethylene nanocomposites are well known for their improved properties when compared with the neat polymers. In this work we report the preparation, characterization and the activity studies of a fourth generation Ziegler-Natta catalyst for the preparation of polyolefin/clay nanocomposites. The catalyst was prepared treating an organo-modified silicate with magnesium and titanium compounds. The content of titanium and that of the magnesium of the catalyst were determined by UV-vis spectroscopy and atomic absorption respectively. The first results show that the catalyst is active for propylene polymerization being suitable for polypropylene/clay nanocomposite preparation. The catalyst activity for ethylene polymerization was also investigated. The X-ray diffraction patterns of the polyethylene samples suggest the clay exfoliation occurs in the in situ polymerization, even with high clay loading (about 9 %) indicating that a nanocomposite was formed. (author)

  18. Preparation and Catalytic Application of Novel Water Tolerant Solid Acid Catalysts of Zirconium Sulfate/HZSM-5

    Institute of Scientific and Technical Information of China (English)

    JIANG Ya-jie; JUAN Joon Ching; MENG Xiu-juan; CAO Wei-liang; YARMO Mohd Ambar; ZHANG Jing-chang

    2007-01-01

    Esterification of acrylic acid(AA) to produce AA esters has widespread application in the chemical industry. A series of water tolerant solid acid catalysts was prepared, and characterized by XRD, nitrogen adsorption, TGA-DTA, XPS, and ammonia adsorption FTIR. The effects of Si/Al ratio, zirconium sulfate(ZS) loading on HZSM-5 and calcination temperature on the esterification were investigated. When 20%(mass fraction) ZS is loaded on HZSM-5, the conversion of AA reaches 100%. XRD analysis indicates that ZS is highly dispersed on HZSM-5 because no crystalline structure assigned to ZS is found. Catalytic activity and hydrophobicity of ZS supported on HZSM-5 are higher compared with those of parent ZS or HZSM-5. Results show that this kind of novel catalysts is an efficient water tolerant solid acid catalyst for esterification reactions.

  19. Preparation of Surface Organometallic Catalysts by Gas-Phase Ligand Stripping and Reactive Landing of Mass-Selected Ions

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Grant E.; Laskin, Julia

    2010-12-27

    Organometallic complexes immobilized on surfaces combine the high selectivity of homogeneous catalysts with the ease of separation of catalyst from products of heterogeneous materials. Here we report a novel approach for the highly controlled preparation of surface organometallic catalysts by gas-phase ligand stripping combined with reactive landing of mass-selected ions onto self assembled monolayer surfaces. Collision induced dissociation is used to generate highly reactive undercoordinated metal complexes in the gas-phase for subsequent surface immobilization. Complexes with an open coordination shell around the metal center are demonstrated to show enhanced activity towards reactive landing in comparison to fully ligated species. In situ TOF-SIMS analysis indicates that the immobilized complexes exhibit behaviour consistent with catalytic activity when exposed to gaseous reagents.

  20. Different outlet for preparing nano-TiO2 catalysts for the photodegradation of Black B dye in water

    Directory of Open Access Journals (Sweden)

    Ahmed K. Aboul-Gheit

    2014-09-01

    Full Text Available Two nano-titania catalysts were prepared using two economically varying titanium precursors: titanium tetrachloride (A and titanium isopropoxide (B. The catalysts were calcined at temperatures of 500 °C, 600 °C and 700 °C and characterized using X-ray diffraction (XRD, electron diffraction (ED, BET surface properties and high resolution transmission microscopy (HRTEM. The calcined catalysts were found to differ markedly in their physical characters and TiO2 phases produced as well as their photocatalytic activities. The anatase titania phase diminished from 100% to 83% in TiO2A but from 64% to zero in TiO2B via temperature increase from 500 °C to 700 °C, due to transforming anatase to rutile. The brookite TiO2 phase only appeared (17% in catalyst B500. In general, the catalyst of choice is A600 by virtue of many compositional, economical and catalytic advantages.

  1. Selective preparation of zeolite X and A from flyash and its use as catalyst for biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    Volli, Vikranth; Purkait, M.K., E-mail: mihir@iitg.ernet.in

    2015-10-30

    Highlights: • Flyash was utilized for zeolites preparation for transesterification. • Single phase and highly crystalline zeolite was obtained at flyash/NaOH ratio of 1:1.2. • Si/Al ratio of 2 resulted in the formation of zeolite X. • At 5 wt% of catalyst loading conversion was 84.6%. • The biodiesel obtained has a calorific value of 37.5 MJ/Kg. - Abstract: This work discusses the utilization of flyash for synthesis of heterogeneous catalyst for transesterification. Different types of zeolites were synthesized from alkali fusion followed by hydrothermal treatment of coal flyash as source material. The synthesis conditions were optimized to obtain highly crystalline zeolite based on degree of crystallinity and cation exchange capacity (CEC). The effect of CEC, acid treatment, Si/Al ratio and calcination temperature (800, 900 and 1000 °C) on zeolite formation was also studied. Pure, single phase and highly crystalline zeolite was obtained at flyash/NaOH ratio (1:1.2), fusion temperature (550 °C), fusion time (1 h), hydrothermal temperature (110 °C) and hydrothermal time (12 h). The synthesized zeolite was ion-exchanged with potassium and was used as catalyst for transesterification of mustard oil to obtain a maximum conversion of 84.6% with 5 wt% catalyst concentration, 12:1 methanol to oil molar ratio, reaction time of 7 h at 65 °C. The catalyst was reused for 3 times with marginal reduction in activity.

  2. Highly efficient nonprecious metal catalyst prepared with metal–organic framework in a continuous carbon nanofibrous network

    Science.gov (United States)

    Shui, Jianglan; Chen, Chen; Grabstanowicz, Lauren; Zhao, Dan; Liu, Di-Jia

    2015-01-01

    Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report here a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A⋅cm−3 at 0.9 V or 450 A⋅cm−3 extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed. PMID:26261338

  3. Highly Stereoselective Heterogeneous Diene Polymerization by Co-MFU-4l: A Single-Site Catalyst Prepared by Cation Exchange.

    Science.gov (United States)

    Dubey, Romain J-C; Comito, Robert J; Wu, Zhenwei; Zhang, Guanghui; Rieth, Adam J; Hendon, Christopher H; Miller, Jeffrey T; Dincă, Mircea

    2017-09-13

    Molecular catalysts offer tremendous advantages for stereoselective polymerization because their activity and selectivity can be optimized and understood mechanistically using the familiar tools of organometallic chemistry. Yet, this exquisite control over selectivity comes at an operational price that is generally not justifiable for the large-scale manufacture of polyfolefins. In this report, we identify Co-MFU-4l, prepared by cation exchange in a metal-organic framework, as a solid catalyst for the polymerization of 1,3-butadiene with high stereoselectivity (>99% 1,4-cis). To our knowledge, this is the highest stereoselectivity achieved with a heterogeneous catalyst for this transformation. The polymer's low polydispersity (PDI ≈ 2) and the catalyst's ready recovery and low leaching indicate that our material is a structurally resilient single-site heterogeneous catalyst. Further characterization of Co-MFU-4l by X-ray absorption spectroscopy provided evidence for discrete, tris-pyrazolylborate-like coordination of Co(II). With this information, we identify a soluble cobalt complex that mimics the structure and reactivity of Co-MFU-4l, thus providing a well-defined platform for studying the catalytic mechanism in the solution phase. This work underscores the capacity for small molecule-like tunability and mechanistic tractability available to transition metal catalysis in metal-organic frameworks.

  4. Preparation, structural characterization and catalytic properties of Co/CeO2 catalysts for the steam reforming of ethanol and hydrogen production

    Science.gov (United States)

    Lovón, Adriana S. P.; Lovón-Quintana, Juan J.; Almerindo, Gizelle I.; Valença, Gustavo P.; Bernardi, Maria I. B.; Araújo, Vinícius D.; Rodrigues, Thenner S.; Robles-Dutenhefner, Patrícia A.; Fajardo, Humberto V.

    2012-10-01

    In this paper, Co/CeO2 catalysts, with different cobalt contents were prepared by the polymeric precursor method and were evaluated for the steam reforming of ethanol. The catalysts were characterized by N2 physisorption (BET method), X-ray diffraction (XRD), UV-visible diffuse reflectance, temperature programmed reduction analysis (TPR) and field emission scanning electron microscopy (FEG-SEM). It was observed that the catalytic behavior could be influenced by the experimental conditions and the nature of the catalyst employed. Physical-chemical characterizations revealed that the cobalt content of the catalyst influences the metal-support interaction which results in distinct catalyst performances. The catalyst with the highest cobalt content showed the best performance among the catalysts tested, exhibiting complete ethanol conversion, hydrogen selectivity close to 66% and good stability at a reaction temperature of 600 °C.

  5. Preparation of novel CdS-incorporated special glass composite as photocatalyst material used for catalyst-fixed system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Maochang; Jing, Dengwei; Zhao, Liang; Guo, Liejin [State Key Laboratory of Multiphase Flow, Xi' an Jiaotong University, Xi' an 710049 (China)

    2010-07-15

    A novel catalyst-fixed way is present. And two series of novel CdS-incorporated special glass composite photocatalysts working under visible light were successfully prepared in this way by a two-step thermal sulfidation procedure for the use of catalyst-fixed system. One was by a high temperature way, and the other was by a low temperature way. The composite photocatalysts with different content of CdS prepared by the methods were found to show a good activity for the decomposition of water under visible light. The highest rate of H{sub 2} revolution is 1549 {mu}mol/(hg{sub CdS}) with wt1%-Pt loaded. The composites prepared by high and low temperature were characterized by X-ray diffraction (XRD), diffuse reflectance UV-vis spectra and scanning electron microscopy (SEM). The as-prepared photocatalysts exhibited different photochemical and photophysical properties for the combined way between glass-base and CdS. The photochemical and photophysical properties were very important in the catalyst-fixed system used for large-scale hydrogen production. (author)

  6. A Novel Way to Prepare γ-Al2O3 Supported SO42-/ZrO2 Solid Superacid Catalysts for n-Butane Isomerization

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Highly active solid superacid catalysts for n-butane isomerization, SZ/Al2O3-P, were prepared by supporting SO42-/ZrO2 (SZ) on γ-Al2O3 carrier using a precipitation method.The activities of some catalysts were enhanced significantly.The activity of the most active sample, 60%SZ/Al2O3-P, was even about 2 times more active than that of the SZ catalyst.

  7. Steam reforming of methane over Ni catalysts prepared from hydrotalcite-type precursors:Catalytic activity and reaction kinetics

    Institute of Scientific and Technical Information of China (English)

    Yang Qi; Zhenmin Cheng; Zhiming Zhou

    2015-01-01

    Ni/Mg–Al catalysts derived from hydrotalcite-type precursors were prepared by a co-precipitation technique and applied to steam reforming of methane. By comparison with Ni/γ-Al2O3 and Ni/α-Al2O3 catalysts prepared by in-cipient wetness impregnation, the Ni/Mg–Al catalyst presented much higher activity as a result of higher specific surface area and better Ni dispersion. The Ni/Mg–Al catalyst with a Ni/Mg/Al molar ratio of 0.5:2.5:1 exhibited the highest activity for steam methane reforming and was selected for kinetic investigation. With external and inter-nal diffusion limitations eliminated, kinetic experiments were carried out at atmospheric pressure and over a temperature range of 823–973 K. The results demonstrated that the overal conversion of CH4 and the conversion of CH4 to CO2 were strongly influenced by reaction temperature, residence time of reactants as wel as molar ratio of steam to methane. A classical Langmuir–Hinshelwood kinetic model proposed by Xu and Froment (1989) fitted the experimental data with excellent agreement. The estimated adsorption parameters were consistent thermodynamical y.

  8. Ag-Cu Bimetallic Nanoparticles Prepared by Microemulsion Method as Catalyst for Epoxidation of Styrene

    Directory of Open Access Journals (Sweden)

    Hong-Kui Wang

    2012-01-01

    Full Text Available Ag/Cu bimetallic nanocatalysts supported on reticulate-like γ-alumina were prepared by a microemulsion method using N2H4·H2O as the reducing agent. The catalysts were activated by calcination followed with hydrogen reduction at 873K, and the properties were confirmed using various characterization techniques. Compared with metal oxides particles, Ag-Cu particles exhibited smaller sizes (<5 nm after calcination in H2 at 873K. XPS results indicated that the binding energies changed with the Ag/Cu ratios, suggesting that increasing the copper content gave both metals a greater tendency to lose electrons. Furthermore, Ag-Cu bimetallic nanoparticles supported on γ-alumina showed better catalytic activity on the epoxidation of styrene as compared with the corresponding monometallic silver or copper. The styrene oxide selectivity could reach 76.6% at Ag/Cu molar ratio of 3/1, while the maximum conversion (up to 94.6% appeared at Ag/Cu molar ratio of 1/1 because of the maximum interaction between silver and copper.

  9. Development of a Method for the Preparation of Ruthenium Indenylidene-Ether Olefin Metathesis Catalysts

    Directory of Open Access Journals (Sweden)

    Yann Schrodi

    2012-05-01

    Full Text Available The reactions between several derivatives of 1-(3,5-dimethoxyphenyl-prop-2-yn-1-ol and different ruthenium starting materials [i.e., RuCl2(PPh33 and RuCl2(p-cymene(L, where L is tricyclohexylphosphine di-t-butylmethylphosphine, dicyclohexylphenylphosphine, triisobutylphosphine, triisopropylphosphine, or tri-n-propylphosphine] are described. Several of these reactions allow for the easy, in-situ and atom-economic preparation of olefin metathesis catalysts. Organic precursor 1-(3,5-dimethoxyphenyl-1-phenyl-prop-2-yn-1-ol led to the formation of active ruthenium indenylidene-ether complexes, while 1-(3,5-dimethoxyphenyl-prop-2-yn-1-ol and 1-(3,5-dimethoxyphenyl-1-methyl-prop-2-yn-1-ol did not. It was also found that a bulky and strong σ-donor phosphine ligand was required to impart good catalytic activity to the new ruthenium complexes.

  10. Preparation and Photocatalytic Properties of TiO2-Al2O3 Composite Loaded Catalysts

    Directory of Open Access Journals (Sweden)

    Jianzhong Pei

    2015-01-01

    Full Text Available This paper presents an experimental approach to study catalytic effects of Fe3+ modified nanometer titanium dioxide (TiO2 loaded on aluminium oxide (Al2O3. Sol-gel method was used to prepare modified TiO2 loaded on carrier. Purification tests were conducted in a self-developed instrument to study catalytic effects of TiO2 loaded on Al2O3 with different contents through degradation rate. The modification mechanism was studied by scanning electron microscope (SEM. Results showed that loading on Al2O3 improved photocatalytic effect of TiO2 modified with Fe3+. The best photocatalytic effect was achieved under catalytic action of Al2O3 loaded with 10% TiO2 composite; the degradation rates were 6.9%, 13.8%, 21.4%, and 49.2%, respectively, 0.7%, 3.9%, 1.3%, and 15.1% larger than unloaded TiO2. SEM results of four catalysts showed that nanometer TiO2 was coated in form of grain on the surface of Al2O3. The optimal loading content was 10% at which the nanometer TiO2 grains were coated on the surface of Al2O3 uniformly.

  11. Ultrafast and large scale preparation of superior catalyst for oxygen evolution reaction

    Science.gov (United States)

    Tian, Xianqing; Liu, Yunhua; Xiao, Dan; Sun, Jie

    2017-10-01

    The development of efficient and earth abundant catalyst for the oxygen evolution reaction (OER) is a key challenge for the renewable energy research community. Here, we report a facile and ultrafast route to immobilize nickel-iron layered double hydroxide (NiFe-LDH) nanoparticles on nickel foam (NF) via soaking the direct electroless deposited prussian blue analogue (PBA) on NF in 1 M KOH. This NiFe-LDH/NF electrode can be prepared in a few seconds without further treatments. It has three-dimensional interpenetrating network originated from its PBA precursor which facilitate the diffusion and ad/desorption of the reactants and producing for OER. And further characterization of the Faradaic efficiency and forced convection tests show direct evidence to demonstrate the formation of free intermediate(s) in the OER process. This electrode (typically NiFe-LDH-20s/NF) exhibits outstanding electrocatalytic activity with low overpotential of ∼0.240 V at 10 mA cm-2, low Tafel slope of 38 mV dec-1, and great stability. This feasible strategy affords a new strategy for the large scale manufacture of low-cost, effective and robust OER electrodes.

  12. Acetones Removal with Fe Doped Titanium Nano Tube Catalysts Prepared from Slag Iron in Steel Plant.

    Science.gov (United States)

    Lin, Yu-Jung; Wen-ZhiCao; Chang, Chang-Tang

    2016-01-01

    TiO₂ has been studied most commonly because it has high stability, non-toxicity, high catalytic activity, and highly conductivity. Many studies have shown that TiO₂ would generate electron-hole pairs illuminated with UV and surround more energy than that before being illuminated. However, the surface area of TiO₂ is not large enough and the adsorption capacity is small. In this study, the titanium nano tube (TNT) catalysts were prepared to increase the surface area and adsorption capacity. The Fe-TNT was also prepared from slag iron since many slag iron cause waste treatment problems. In this study, the effect of Fe loading, including 0.77%, 1.13%, 2.24% and 4.50%, on acetone removal was also assessed since TNT doped with transitional or precious metals can be used to improve catalytic reaction efficiency. Furthermore, four kinds of VOCs concentration, including 250, 500, 1000 and 1500 ppm were tested. Four kinds of retention time, including 0.4, 0.8, 4.0 and 6.0 sec, and four kinds of dosage, including 0.15, 0.25, 0.30 and 0.45 g cm⁻³, were also assessed. In this study, the adsorption capacity of Fe-TNT was 18.8, 23.3, 28.9 and 32.6 mg g⁻¹ for acetone of 250, 500, 1000 and 1500 ppm, respectively. Four kinds of temperature, including 150, 200, 250 and 300 °C were tested in catalytic reaction system. The results showed removal efficiency increased with increasing temperature. The efficiency can be reached 95% under the conditions with the dosage higher than 0.3 g cm⁻³, temperature higher than 270 °C and retention time higher than 270 °C. Reaction efficiency was 20, 31, 41 and 96% at the temperature of 150, 200, 250 and 300 °C, respectively.

  13. Preparation of Co-Mo catalyst using activated carbon produced from egg shell and SiO2 as support – A hydrogenation study

    Directory of Open Access Journals (Sweden)

    Adeniyi Sunday Ogunlaja

    2010-12-01

    Full Text Available The preparation of a series of cobalt-molybdenum (Co-Mo catalysts supported on SiO2 and carbonized egg shells were investigated using standard procedures; the catalysts were further calcined at the 500 oC temperature to generate the internally consistent set, and the metal atoms content were varied in a regular manner. The ratio 1:4 (Co2+: Mo6+ by weight was employed for the various catalysts prepared. The carbonized egg shells were divided into two parts: the first part was leached with HNO3, as the other one was not leached. Activity tests were run using these catalysts containing leached and unleached carbon for the hydrogenation of methyl orange; the changes in absorbance regarding the unhydrogenated methyl orange at a wavelength of 460 nm were respectively 0.07 and 0.067 when the catalyst containing the leached carbonized egg shell (catalyst A and the catalyst containing the unleached activated carbon (catalyst B were used for the hydrogenation reaction. This confirms that catalyst A is more efficient in hydrogenating methyl orange than catalyst B.

  14. Influence of complexing agents on the preparation of bimetallic platinum-ruthenium catalysts supported on O-functionalized graphite cloths

    Energy Technology Data Exchange (ETDEWEB)

    Sieben, J.M., E-mail: jmsieben@uns.edu.a [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Universidad Nacional del Sur., Av. Alem 1253, (B8000CPB) Bahia Blanca (Argentina); Duarte, M.M.E.; Mayer, C.E. [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Universidad Nacional del Sur., Av. Alem 1253, (B8000CPB) Bahia Blanca (Argentina)

    2010-02-18

    Electrodeposition of bimetallic Pt-Ru catalysts on O-functionalized graphite cloths from H{sub 2}PtCl{sub 6} and RuCl{sub 3} solutions containing trisodium citrate (Cit) and disodium dihydrogen ethylenediaminetetraacetate (Na{sub 2}H{sub 2}EDTA) was investigated. SEM analysis of the electrode prepared without complexant showed a relatively compact and rough deposit displaying a 'tree cortex' structure, whereas uniform size and globular shape particles regularly distributed over the support surface were obtained using citrate and Na{sub 2}H{sub 2}EDTA as complexants. In addition, XRD diffraction and EDX analysis revealed that the catalysts prepared using the complexants showed smaller size particles and lower Ru content. Electrocatalytic activity measurements indicated that the most active electrode for methanol oxidation was obtained with Na{sub 2}H{sub 2}EDTA as additive.

  15. Manganese-cerium oxide catalysts prepared by non-thermal plasma for NO oxidation: Effect of O2 in discharge atmosphere

    Science.gov (United States)

    Liu, Lu; Zheng, Chenghang; Wu, Shenghao; Gao, Xiang; Ni, Mingjiang; Cen, Kefa

    2017-09-01

    Non-thermal plasma with different O2 concentration in discharge atmosphere was applied to synthesize manganese and cerium mixed-oxides catalysts, which were compared in NO oxidation activity. Discharge atmosphere displayed a crucial influence on the performance of the catalysts prepared by plasma. Relatively low O2 concentration in discharge atmosphere allows synthesizing manganese-cerium oxides catalysts in a moderate environment and therefore is favorable for better physicochemical properties which lead to superior catalytic behavior. The best catalyst was obtained by treatment with 10% O2/N2 plasma and presented over 80% NO conversion in the temperature range of 275-325 °C, whereas catalyst prepared in pure O2 discharge atmosphere had the same activity with a catalyst prepared by calcinations. A correlation between the surface properties of the plasma prepared catalysts and its catalytic activity in NO oxidation is proposed. The amount of the surface adsorbed oxygen has an obvious linear correlation with the amount of Ce3+, the H2 consumption at low temperatures and the catalytic performance. The superior catalytic performance is mainly attributed to the stronger interaction between manganese oxides and ceria, and the formation of poorly crystallized Mn-O-Ce phase in the catalyst which resulted from the slow decomposition of nitrates and organics during plasma treatment. Catalysts prepared in relatively low O2 concentration have large specific surface area and is abundant in Ce3+ species and active oxygen species. The study suggests that plasma treatment with proper discharge gas components is a promising method to prepare effective manganese- cerium oxides catalyst for NO oxidation.

  16. In situ growth of carbon nanotubes on Ni/MgO: a facile preparation of efficient catalysts for the production of synthetic natural gas from syngas.

    Science.gov (United States)

    Fan, M T; Lin, J D; Zhang, H B; Liao, D W

    2015-11-07

    Ni/MgO-CNTs catalysts are prepared by in situ chemical vapor deposition growth of CNTs on Ni/MgO. These catalysts exhibit an improved performance for the production of synthetic natural gas from syngas, which is attributed to the formation of highly catalytic active interfaces among Ni, CNTs and MgO.

  17. Preparation and study of IrO2/SiC–Si supported anode catalyst for high temperature PEM steam electrolysers

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Tomás García, Antonio Luis; Petrushina, Irina;

    2011-01-01

    of the IrO2 particles, affecting the IrO2 particle size. The prepared catalysts were electrochemically characterised by cyclic voltammetry experiments at 25,80,120 and 150 °C. In accordance with the observed variation in particle size, a support loading of up to 20% improved the activity of the catalyst...

  18. Preparation and characterization of nano-sized Pt-Ru/C catalysts and their superior catalytic activities for methanol and ethanol oxidation.

    Science.gov (United States)

    Şen, Selda; Şen, Fatih; Gökağaç, Gülsün

    2011-04-21

    Carbon-supported PtRu nanoparticles (Ru/Pt: 0.25) were prepared by three different methods; simultaneous reduction of PtCl(4) and RuCl(3) (catalyst I) and changing the reduction order of PtCl(4) and RuCl(3) (catalysts II and III) to enhance the performance of the anodic catalysts for methanol and ethanol oxidation. Structure, microstructure and surface characterizations of all the catalysts were carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM) coupled with energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The results of the XRD analysis showed that all catalysts had a face-centered cubic (fcc) structure with different and smaller lattice parameters than that of pure platinum, showing that the Ru incorporates into the Pt fcc structure by different ratios in all the catalysts. The typical particle sizes of all catalysts were in the range of 2-3 nm. The most active and stable catalyst for methanol and ethanol oxidation is catalyst III, in which a large amount (more than 90%) of PtRu alloy formation was observed. It has been found that this catalyst is about 8.0 and 33.4 times more active at ∼0.60 V towards the methanol and ethanol oxidation reactions, respectively, compared to the commercial Pt catalyst.

  19. Preparation and Application of Carbon-Nanofiber Based Microstructured Materials as Catalyst Supports

    NARCIS (Netherlands)

    Chinthaginjala, J.K.; Seshan, K.; Lefferts, L.

    2007-01-01

    In the application of heterogeneous catalysts in liquid phase reactions, the rate of reaction as well as selectivity is often negatively influenced by mass transfer limitations in the stagnant liquid in the pores of the catalyst support. Internal mass transfer limitations can be reduced by maximizin

  20. Raney copper catalysts for the water-gas shift reaction: I. Preparation, activity and stability

    CSIR Research Space (South Africa)

    Mellor, JR

    1997-12-23

    Full Text Available at the stated conditions compared favourably to the co-precipitated and industrial catalyst alternatives due to a similar active phase composition and high metallic copper surface areas. Raney copper catalyst deactivation in a poison-free environment...

  1. Preparation of L-Butyl Lactate via Transesterification by Using Nafion-H Catalyst

    Institute of Scientific and Technical Information of China (English)

    Wei LI; Guo Rong ZHENG; Ping LU

    2005-01-01

    Optically pure L-butyl lactate was synthesized by normal transesterification using nafion-H catalyst in moderate yield. Various reaction conditions were investigated, including the reaction temperature, reaction time, ratio of the starting material and amount of the nafion catalyst.

  2. Preparation of Dendritic Carbosilane-supported Palladium Catalyst and Its Catalytic Activity in Hydrogenation of Organic Compounds

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The preparation of palladium complex from PdCl2·2H2O and earbosilane dendrimers with peripheral aminopropyl groups was described. The compound obtained was characterized by IR, 1H NMR, X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission spectrometric (ICP-AES) spectroscopy respectively. The metal complex was employed as catalyst in hydrogenation of organic compounds. The high activity of the complex was probably due to the formation of the eoordinatively unsaturated palladium.

  3. Thermal hydrocracking of indan. Effects of the hydrogen pressure on the kinetics and Arrhenius parameters

    NARCIS (Netherlands)

    Boven, van M.; Roskam, G.J.; Penninger, J.M.L.

    1975-01-01

    The kinetics of the thermal hydrocracking of indan were investigatedin a high-pressure flow reactor at temperatures from 470 to 530°C, total pressures of up to 300 atm, and molar ratios from 3 to 40. The effect of the hydrogen pressure was reflected especially in a change of the experimental rate eq

  4. Improvement of hydrogen solubility and entrainment in hydrocracker feedstocks. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Kabadi, V.N.

    1997-02-01

    The project consisted of two tasks: (1) development of a thermodynamic model for hydrogen solubility in hydrocarbons and extension of this model to predict solubility of hydrogen in hydrocracker feedstocks at conditions similar to those of hydrocracking operations, and (2) design and construction of a gas solubility apparatus to measure solubility of hydrogen in hydrocarbons and in hydrocracker feedstocks. The theoretical work proposed was fully accomplished by developing a sophisticated model for hydrogen solubility in hydrocarbons and in hydrocracker feedstocks at advanced temperatures and pressures. The proposed experimental work ran into a number of obstacles, especially to get the original and newly designed on-line sampling technique to function properly. A number of calibrations and tests for reproducibility were necessary to assure the accuracy of measured data. Although a very well designed gas solubility apparatus was built, not much time was left to generate significant hydrogen solubility data. The plans are to use the apparatus in future to measure hydrogen solubility data in liquid fuels to facilitate more efficient design of fuel conversion systems.

  5. Thermal hydrocracking of indan. Effects of the hydrogen pressure on the kinetics and Arrhenius parameters

    NARCIS (Netherlands)

    van Boven, M.; Roskam, G.J.; Penninger, J.M.L.

    1975-01-01

    The kinetics of the thermal hydrocracking of indan were investigatedin a high-pressure flow reactor at temperatures from 470 to 530°C, total pressures of up to 300 atm, and molar ratios from 3 to 40. The effect of the hydrogen pressure was reflected especially in a change of the experimental rate

  6. Preparation, characterization of Mo catalysts supported on Ni- containing calcium deficient hydroxyapatite and reactivity for the thiophene HDS reaction

    Directory of Open Access Journals (Sweden)

    Cherif A.

    2013-09-01

    Full Text Available Ni-containing Calcium Hydroxyapatite (NiCaHAp; 3.31 wt.% Ni was synthesized by coprecipitation and used as catalyst support. Molybdenum was supported on NiCaHAp by impregnation using ammonium heptamolybdate. The prepared catalysts Mo(x/NiCaHAp (x: 2 to 8 wt % in Mo were characterized by elemental analysis, XRD, FT-IR, N2 adsorption-desorption and TEM-EDX. The catalysts were sulfided in-situ at 673 K under flowing H2S/H2 (15 Vol.% H2S and tested in hydrodesulfurization (HDS of thiophene at 673 K. The main XRD peaks of hydroxyapatite CaHAp phase were observed in all samples and a peak due probably to crystalline MoO3 phase was also identified from the results. However, no crystalline phase of NiO was found for the catalysts, which showed its Ni species were highly dispersed. The sulfided catalysts Mo(x/NiCaHAp presented are active in HDS of thiophene, despite the presence of some large MoO3 crystallites and incomplete sulfidation. This activity may be due to interaction of NiO and MoO3 on CaHAp resulting in the formation of Ni-Mo-S phase under flowing H2S/H2. When the molybdenum content increased the HDS activity increasead slightly, which was caused by the agglomeration of MoO3. The Mo(8/NiCaHAp catalyst is about two times less active for thiophene HDS than the commercial NiMoP/Al2O3.

  7. In situ upgrading : coupled enhanced oil recovery with in situ upgrading : ultra dispersed catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Almao, P.P. [Calgary Univ., AB (Canada). Schulich School of Engineering]|[Alberta Ingenuity Centre for In Situ Energy, Edmonton, AB (Canada)

    2007-07-01

    This paper presented a research program that demonstrates the use of ultra dispersed (UD) catalysts as a means of improving the economics of oil sands processing. An outline of current processing techniques was provided. In situ upgrading options included the use of solvents, thermal methods, radiation methods, bio-upgrading, and thermo-catalytic methods. Enhanced oil recovery (EOR) is often combined with in situ upgrading to increase the efficiency of energy use in reservoirs where thermal methods are used. The use of diluents often reduces water usage as well as problems related to contamination and emissions. Recent studies have suggested that vis-breaking (VB) is the lowest investment residual conversion process currently available for in situ processing. UD catalyst formulations can be commercially prepared using nano-particle techniques, and can be used in portable configurations. UD catalysts are known to outperform conventional fixed bed types for both hydrogenation, hydrotreating, and hydrocracking. Research is currently being conducted at the Alberta Ingenuity Centre for In Situ Energy to examine issues related to particles recycling, deactivation and losses. Permeability studies are also being conducted to examine permeability rates of emulsions and nanoparticles through oil sands porous media. The short term financial rewards of various in situ upgrading technologies were also considered. refs., tabs, figs.

  8. Preparation of ZrO2/Al2O3-montmorillonite composite as catalyst for phenol hydroxylation

    Directory of Open Access Journals (Sweden)

    Is Fatimah

    2014-11-01

    Full Text Available Zirconium dispersed in aluminum-pillared montmorillonite was prepared as a catalyst for phenol hydroxylation. The effects of varying the Zr content on the catalyst’s physicochemical character and activity were studied with XRD, BET surface area analysis, surface acidity measurements and scanning electron microscopy before investigating the performance for phenol conversion. The zirconia dispersion significantly affects the specific surface area, the total surface acidity and surface acidity distribution related to the formation of porous zirconia particles on the surface. The prepared samples exhibited excellent catalytic activity during phenol hydroxylation.

  9. Al2O3-Cact-(CuO, Cr2O3, Co3O4 Adsorbents-Catalysts: Preparation and Characterization

    Directory of Open Access Journals (Sweden)

    Gitana DABRILAITĖ-KUDŽMIENĖ

    2013-03-01

    Full Text Available Al2O3-Cact-(CuO, Cr2O3 Co3O4 adsorbents-catalysts were prepared using Al2O3-Cact (alumina gel–activated carbon adsorbent and different amount of CuO, Cr2O3 and Co3O4. The active components were incorporated into wet alumina gel–carbon mixture using different conditions (by sol-gel method and mixing a milled metal oxides. Equilibrium adsorptive capacity measurements of alcohol vapours were carried out in order to determine the influence of preparation conditions on the stability of prepared adsorbents–catalysts. Specific surface area of the prepared adsorbents-catalysts were measured by BET method. It was established that for adsorbent-catalyst produced by sol-gel method SBET = 244.7 m2/g. Surface area SBET = 29.32 m2/g was obtained for adsorbent-catalyst with metal oxides. On the basis of these results it was assumed that active carbon was lost in this adsorbent-catalyst during the preparation process. Sol-gel derived adsorbent–catalyst was tested for the oxidation of methanol vapours. Catalytic oxidation was carried out in fixed-bed reactor. Experimental data indicate that adsorptive capacity of the adsorbent–catalyst is (3.232 – 3.259 mg/m3 CH3OH at relative air humidity is 40 % – 50 %. During a fast heating of CH3OH – saturated adsorbent-catalyst a part of adsorbate is converted to CO2 and H2O. Methanol conversion increases with increasing of adsorbent-catalyst heating rate.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3832

  10. Catalyst used in 1,2-epoxyalkane preparation is obtained by heating tetraalkyl ammonium salts, tetraalkyl siloxanes and amines, calcining and treating with a tetraalkoxy compound

    DEFF Research Database (Denmark)

    2001-01-01

    NOVELTY - The catalyst, used in 1,2-epoxyalkane preparation, is obtained by heat treating an aqueous composition comprising tetraalkyl ammonium salts, tetraalkyl siloxanes and amines, removing the template by calcining and treating with a tetraalkoxy compound......NOVELTY - The catalyst, used in 1,2-epoxyalkane preparation, is obtained by heat treating an aqueous composition comprising tetraalkyl ammonium salts, tetraalkyl siloxanes and amines, removing the template by calcining and treating with a tetraalkoxy compound...

  11. [Preparation of red mud loaded Co catalysts: optimization using response surface methodology (RSM) and activity evaluation].

    Science.gov (United States)

    Li, Hua-Nan; Xu, Bing-Bing; Qi, Fei; Sun, De-Zhi

    2013-11-01

    The removal efficiency of catalytic ozonation of bezafibrate (BZF) by red mud loaded Co catalysts (Co/RM) was used as the index value in statistical experimental designs. The most important factors influencing BZF degradation (P red mud, enhanced the catalytic activity. Moreover, the dissolved metal concentration in the solution for catalytic ozonation of BZF degradation by RM or Co/RM was determined by ICP-OES. The results showed that for both catalysts there was no leaching of catalytic active components into the solution, which could suggest that the two catalysts were safe and could have certain application prospect.

  12. Pt-free carbon-based fuel cell catalyst prepared from spherical polyimide for enhanced oxygen diffusion

    Science.gov (United States)

    Nabae, Yuta; Nagata, Shinsuke; Hayakawa, Teruaki; Niwa, Hideharu; Harada, Yoshihisa; Oshima, Masaharu; Isoda, Ayano; Matsunaga, Atsushi; Tanaka, Kazuhisa; Aoki, Tsutomu

    2016-03-01

    The development of a non-precious metal (NPM) fuel cell catalyst is extremely important to achieve globalization of polymer electrolyte fuel cells due to the cost and scarcity of platinum. Here, we report on a NPM cathode catalyst prepared by the pyrolysis of spherical polyimide nanoparticles that contain small amounts of Fe additive. 60 nm diameter Fe-containing polyimide nanoparticles were successfully synthesized by the precipitation polymerization of pyromellitic acid dianhydride and 1,3,5-tris(4-aminophenyl)benzene with Fe(acac)3 (acac = acetylacetonate) as an additive. The particles were subsequently carbonized by multistep pyrolysis to obtain the NPM catalyst while retaining the small particle size. The catalyst has good performance and promising durability for fuel cell applications. The fuel cell performance under a 0.2 MPa air atmosphere at 80 °C of 1.0 A cm‑2 at 0.46 V is especially remarkable and better than that previously reported.

  13. Cobalt based catalysts prepared by Pechini method for CO{sub 2}-free hydrogen production by methane decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Jana, Prabhas; de la Pena O' Shea, Victor A.; Coronado, Juan M. [Thermochemical Process Unit, Instituto IMDEA Energia, C/Tulipan s/n 28933, Mostoles, Madrid (Spain); Serrano, David P. [Thermochemical Process Unit, Instituto IMDEA Energia, C/Tulipan s/n 28933, Mostoles, Madrid (Spain); Department of Chemical and Environmental Technology, ESCET, Rey Juan Carlos University, c/ Tulipan s/n, 28933 Mostoles, Madrid (Spain)

    2010-10-15

    A variety of unsupported cobalt catalysts was synthesized using the Pechini method and tested for CO{sub 2}-free H{sub 2} production via methane decomposition. In order to study the influence of the synthesis conditions on the properties of cobalt materials, the Cobalt:Citric acid (Co:CA) ratio was varied systematically (from 1:2 to 1:20). In addition, a study of the effect of the activation process on the catalyst activity was performed by activating the catalyst with H{sub 2} or CH{sub 4}. In both the activation processes, metallic cobalt with fcc structure was obtained, but the particle morphology varied with the activation treatment. The catalytic behavior was highly influenced when the reduction procedure was performed under methane atmosphere. For the Co:CA ratios, the best results were obtained with the catalyst prepared with a Co:CA 1:20 ratio reduced in presence of methane, which shows a production of 6.47 mol of H{sub 2} per mol of cobalt even without deactivation behavior for 30 min of the reaction period. (author)

  14. Al 2O 3 supported Ru catalysts prepared by thermolysis of Ru 3(CO) 12 for catalytic wet air oxidation

    Science.gov (United States)

    Yu, Chaoying; Zhao, Peiqing; Chen, Gexin; Hu, Bin

    2011-06-01

    Low loading catalysts Ru/γ-Al 2O 3 and Ru-Ce/γ-Al 2O 3 were prepared by thermolysis of Ru 3(CO) 12 on γ-Al 2O 3. The catalysts were characterized by XPS, XRD and SEM. Two new Ru species (Ru A and Ru B) were detected during the Ru 3(CO) 12 decomposition process due to chemical interaction with the active OH groups on the surface of Al 2O 3 support, and the reduction of them can lead to more dispersed metallic phases. The sample was completely decomposed at 673 K in H 2, and RuO 2 was formed with minor amounts of Ru 0. When the temperature was increased to 773 K to heat the sample, the ratio of Ru 0 to RuO 2 increased. However, after the addition of CeO 2, only RuO 2 was detected on surface. The catalysts exhibited high activities in Catalytic Wet Air Oxidation (CWAO) of different organic compounds at high concentration such as isopropyl alcohol, phenol, acetic acids and N,N-dimethylformamide, which is attributed to the better dispersion of Ru particles and the addition of CeO 2 further enhanced number of effectively active sites on the cluster-derived catalyst surface.

  15. Ni/MgO catalyst prepared using atmospheric high-frequency discharge plasma for CO2 reforming of methane

    Institute of Scientific and Technical Information of China (English)

    Pan Qin; Huiyuan Xu; Huali Long; Yi Ran; Shuyong Shang; Yongxiang Yin; Xiaoyan Dai

    2011-01-01

    A new type of Ni/MgO catalyst was prepared using atmospheric high-frequency discharge cold plasma.The influences of conventional method,plasma method,and plasma plus calcination method on the catalytic activity were studied and the CO2 reforming of methane was chosen as the probe reaction.The catalysts were characterized by X-ray diffraction (XRD),transmission electron microscope (TEM),X-ray photoelectron spectroscopy,and CO2 temperature-programmed surface reaction techniques.The results suggested that the nickel-based catalyst prepared by plasma plus calcination method possessed a smaller particle size and a higher dispersion of active component,better low-temperature activity and enhanced anti-coking ability.The conversion of CO2 and CH4 was 90.70% and 89.37%,respectively,and the reaction lasted for 36 h without obvious deactivation under 101.325 kPa and 750 ℃ with CO2/CH4 =1/1.

  16. A Microwave-Sensitive Solid Acid Catalyst Prepared from Sweet Potato via a Simple Method

    Directory of Open Access Journals (Sweden)

    Hai-Ying Chen

    2016-12-01

    Full Text Available In this study, a microwave-sensitive solid acid catalyst was successfully synthesized from sweet potatoes via a simple process. The catalyst was proven to have superior microwave-sensitive and homogeneous properties. The physicochemical properties were characterized by Brunauer–Emmett–Teller (BET, X-ray diffraction (XRD, Fourier-transform infrared spectra (FT-IR, thermogravimetric (TGA, scanning electron microscope (SEM and elemental analysis (EA. Results showed that the total acid density and specific surface area for the catalyst were 6.35 mmol/g and 78.35 m2/g, respectively. The elemental sulfur content reached 7.449% after sulfonation and the catalytic activity could reach over 91% within 30 min with microwave power density of 1.0 W/mL. The catalytic reaction temperature should not exceed 200 °C, as shown in TGA curve, and the moisture content in the oil raw material should be within 1%–2%. The catalyst deactivated gradually to 64.38% after reutilization five times, but the catalytic activity could be simply regenerated by re-sulfonation, albeit slightly reduced (87.56%. The shift of diffraction peaks in the XRD patterns and new absorption peaks at 619.98 and 1190.49 cm−1 of FT-IR spectra demonstrated that the –SO3H group was effectively attached to the catalyst. The SEM images displayed a loose and porous amorphous structure in the end catalyst.

  17. Preparation and Characterization of Zirconia-Coated Nanodiamonds as a Pt Catalyst Support for Methanol Electro-Oxidation

    Directory of Open Access Journals (Sweden)

    Jing Lu

    2016-12-01

    Full Text Available Zirconia-coated nanodiamond (ZrO2/ND electrode material was successfully prepared by one-step isothermal hydrolyzing from ND-dispersed ZrOCl2·8H2O aqueous solution. High-resolution transmission electron microscopy reveals that a highly conformal and uniform ZrO2 shell was deposited on NDs by this simple method. The coating obtained at 90 °C without further calcination was mainly composed of monoclinic nanocrystalline ZrO2 rather than common amorphous Zr(OH4 clusters. The ZrO2/NDs and pristine ND powder were decorated with platinum (Pt nanoparticles by electrodeposition from 5 mM chloroplatinic acid solution. The electrochemical studies indicate that Pt/ZrO2/ND catalysts have higher electrocatalytic activity and better stability for methanol oxidation than Pt/ND catalysts in acid.

  18. Nickel-carbon nanocomposites prepared using castor oil as precursor: A novel catalyst for ethanol steam reforming

    Science.gov (United States)

    Carreño, Neftalí L. V.; Garcia, Irene T. S.; Raubach, Cristiane W.; Krolow, Mateus; Santos, Cláudia C. G.; Probst, Luiz F. D.; Fajardo, Humberto V.

    A novel and simple method to prepare nickel-based catalysts for ethanol steam reforming is proposed. The present method was developed using castor oil as a precursor. The results clarify that the nickel-carbon (Ni/C) catalyst has a high activity for ethanol steam reforming. It was observed that the catalytic behavior could be modified according to the experimental conditions employed. Moreover, it is interesting to note that the increase in the catalytic activity of the Ni/C nanocomposite over time, at 500 and 600 °C of reaction temperature, may be associated with the formation of filamentous carbon. The preliminary results indicate that the novel methodology used, led to the obtainment of materials with important properties that can be extended to applications in different catalytic process.

  19. Preparation of a new Fenton-like catalyst from red mud using molasses wastewater as partial acidifying agent.

    Science.gov (United States)

    Wei, Guangtao; Shao, Luhua; Mo, Jihua; Li, Zhongmin; Zhang, Linye

    2017-06-01

    Using molasses wastewater as partial acidifying agent, a new Fenton-like catalyst (ACRM sm ) was prepared through a simple process of acidification and calcination using red mud as main material. With molasses wastewater, both the free alkali and the chemically bonded alkali in red mud were effectively removed under the action of H2SO4 and molasses wastewater, and the prepared ACRM sm was a near-neutral catalyst. The ACRM sm preparation conditions were as follows: for 3 g of red mud, 9 mL of 0.7 mol/L H2SO4 plus 2 g of molasses wastewater as the acidifying agent, calcination temperature 573 K, and calcination time 1 h. Iron phase of ACRM sm was mainly α-Fe2O3 and trace amount of carbon existed in ACRM sm . The addition of molasses wastewater not only effectively reduced the consumption of H2SO4 in acidification of red mud but also resulted in the generation of carbon and significantly improved the distribution of macropore in prepared ACRM sm . It was found that near-neutral pH of catalyst, generated carbon, and wide distribution of macropore were the main reasons for the high catalytic activity of ACRM sm . The generated carbon and wide distribution of macropore were entirely due to the molasses wastewater added. In degradation of orange II, ACRM sm retained most of its catalytic stability and activity after five recycling times, indicating ACRM sm had an excellent long-term stability in the Fenton-like process. Furthermore, the performance test of settling showed ACRM sm had an excellent settleability. ACRMsm was a safe and green catalytic material used in Fenton-like oxidation for wastewater treatment.

  20. Effect of method of preparation on hydrodesulphurization activity of Co- or Ni-promoted MoS2/SBA-15 catalysts

    Indian Academy of Sciences (India)

    Shelu Garg; Kapil Soni; V V D N Prasad; Manoj Kumar; Thallada Bhaskar; J K Gupta; G Murali Dhar; C S Gopinath

    2014-03-01

    Ordered mesoporous material SBA-15 was synthesized and used as a support for the preparation of molybdenum sulphide catalysts through precipitation from homogeneous solution (PFHS) technique with the Mo content varying from 2-12 wt%. The prepared catalysts were evaluated for thiophene hydrodesulphurization catalytic activities at 400°RC. Catalysts prepared through PFHS method resulted in highly dispersed MoS2 catalysts, which were inferred from powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), low temperature oxygen chemisorptions (LTOC) and BET surface area analysis. The relationship between XPS intensity ratio, oxygen chemisorption and catalytic activities is discussed in terms of highly dispersed nano particles of MoS2 and its consequence in accommodating more promoted atoms at the edge sites.

  1. Influence of preparation methods on CuO-CeO2 catalysts in the preferential oxidation of CO in excess hydrogen

    Institute of Scientific and Technical Information of China (English)

    Zhigang Liu; Renxian Zhou; Xiaoming Zheng

    2008-01-01

    Influence of three different preparation methods, i.e. impregnation, coprecipitation, and inverse coprecipitation, on the preferential oxidation of CO in excess hydrogen (PROX) over CuO-CeO2 catalysts has been investigated and CuO-CeO2 catalysts are characterized using BET, XPS, XRD, UV Raman, and TPR techniques. The results show that the catalysts prepared by coprecipitation have smaller particle sizes, well-dispersed CuOx species, more oxygen vacancies, and are more active in the PROX than those prepared by the other methods. However, the inverse coprecipitation depresses the catalytic performance of CuO-CeO2 catalysts and causes the growth of CuO-CeO2 because of different pH value in the precipitation process.

  2. Selective catalytic reduction of NOx with NH3 over iron-cerium-tungsten mixed oxide catalyst prepared by different methods

    Science.gov (United States)

    Xiong, Zhi-bo; Liu, Jing; Zhou, Fei; Liu, Dun-yu; Lu, Wei; Jin, Jing; Ding, Shi-fa

    2017-06-01

    A series of magnetic Fe0.85Ce0.10W0.05Oz catalysts were synthesized by three different methods(Co-precipitation(Fe0.85Ce0.10W0.05Oz-CP), Hydrothermal treatment assistant critic acid sol-gel method(Fe0.85Ce0.10W0.05Oz-HT) and Microwave irradiation assistant critic acid sol-gel method(Fe0.85Ce0.10W0.05Oz-MW)), and the catalytic activity was evaluated for selective catalytic reduction of NO with NH3. The catalyst was characterized by XRD, N2 adsorption-desorption, XPS, H2-TPR and NH3-TPD. Among the tested catalysts, Fe0.85Ce0.10W0.05Oz-MW shows the highest NOx conversion over per gram in unit time with NOx conversion of 60.8% at 350 °C under a high gas hourly space velocity of 1,200,000 ml/(g h). Different from Fe0.85Ce0.10W0.05Oz-CP catalyst, there exists a large of iron oxide crystallite(γ-Fe2O3 and α-Fe2O3) scattered in Fe0.85Ce0.10W0.05Oz catalysts prepared through hydrothermal treatment or microwave irradiation assistant critic acid sol-gel method, and higher iron atomic concentration on their surface. And Fe0.85Ce0.10W0.05Oz-MW shows higher surface absorbed oxygen concentration and better dispersion compared with Fe0.85Ce0.10W0.05Oz-HT catalyst. These features were favorable for the high catalytic performance of NO reduction with NH3 over Fe0.85Ce0.10W0.05Oz-MW catalyst.

  3. Effect of substrate preparation on the structure and chemisorption properties of Pd/MgO model catalyst

    Science.gov (United States)

    Henry, C. R.; Poppa, H.

    1988-01-01

    Pd/MgO model catalysts are prepared by vapor deposition of Pd particles on MgO thin films which are deposited, at different temperatures, on UHV cleaved mica. MgO films and Pd particles are characterized in situ by Auger electron spectroscopy and energy-loss spectroscopy and ex situ by transmission electron microscopy. Succesive temperature programmed desorption (TPD) of CO shows a different evolution of the morphology of the Pd particles deposited on MgO films prepared at low and high temperature. In addition, on MgO prepared at low temperature, the smallest particles show a continuous decay of CO adsorption during TPD due to contamination by support species.

  4. Hydrogen Production by Steam Reforming of Liquefied Natural Gas (LNG) Over Nickel-Phosphorus-Alumina Xerogel Catalyst Prepared by a Carbon-Templating Epoxide-Driven Sol-Gel Method.

    Science.gov (United States)

    Bang, Yongju; Park, Seungwon; Han, Seung Ju; Yoo, Jaekyeong; Choi, Jung Ho; Kang, Tae Hun; Lee, Jinwon; Song, In Kyu

    2016-05-01

    A nickel-phosphorus-alumina xerogel catalyst was prepared by a carbon-templating epoxide-driven sol-gel method (denoted as CNPA catalyst), and it was applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). For comparison, a nickel-phosphorus-alumina xerogel catalyst was also prepared by a similar method in the absence of carbon template (denoted as NPA catalyst). The effect of carbon template addition on the physicochemical properties and catalytic activities of the catalysts in the steam reforming of LNG was investigated. Both CNPA and NPA catalysts showed excellent textural properties with well-developed mesoporous structure. However, CNPA catalyst retained a more reducible nickel aluminate phase than NPA catalyst. XRD analysis of the reduced CNPA and NPA catalysts revealed that nickel sintering on the CNPA catalyst was suppressed compared to that on the NPA catalyst. From H2-TPD and CH4-TPD measurements of the reduced CNPA and NPA catalysts, it was also revealed that CNPA catalyst with large amount of hydrogen uptake and strong hydrogen-binding sites showed larger amount of methane adsorption than NPA catalyst. In the hydrogen production by steam reforming of LNG, CNPA catalyst with large methane adsorption capacity showed a better catalytic activity than NPA catalyst.

  5. Metal segregation in supported bimetallic catalysts:. gamma. -Al/sub 2/O/sub 3/-supported CO hydrogenation catalysts prepared from RhOs/sub 3/, Rh/sub 4/, and FeOs/sub 3/ clusters

    Energy Technology Data Exchange (ETDEWEB)

    Budge, J.R.; Lucke, B.F.; Gates, B.C.; Toran, J.

    1985-02-01

    Al/sub 2/O/sub 3/-supported metals were prepared from (H/sub 2/RhOs/sub 3/(CO)/sub 10/(acetylacetonate)), (Rh/sub 4/(CO)/sub 12/), and (H/sub 2/FeOs/sub 3/(CO)/sub 13/). The samples were characterized by infrared spectroscopy after reaction with CO + H/sub 2/ and tested as catalysts for conversion of CO + H/sub 2/ in a flow reactor at 200 and 270/sup 0/C and 10 atm. Used catalysts were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, and elemental analysis. The catalyst lost Os during operation, presumably as a result of formation of volatile carbonyls. The catalytic reaction products were a nearly Schulz-Flory-Anderson distribution of hydrocarbons with small yields of dimethyl ether (formed from methanol). The performance of the catalyst prepared from the RhOs/sub 3/ clusters was closely similar to that of the catalyst prepared from the Rh/sub 4/ cluster. Characterization of the samples after treatment in CO + H/sub 2/ and after catalysis demonstrated that the RhOs/sub 3/ clusters broke apart, first giving triosmium clusters and mononuclear Rh complexes and then, at higher temperatures, giving Rh crystallites and mononuclear Os complexes. The catalytic activity for hydrocarbon synthesis is attributed to the Rh metal; the activity for methanol synthesis is tentatively associated with ionic Rh complexes. The FeOs/sub 3/ catalyst was two orders of magnitude less active than the Rh Os/sub 3/ catalyst, apparently consisting of small iron oxide particles and mononuclear Os complexes. The selectivity of this catalyst for dimethyl ether formation increased markedly with time onstream in the flow reactor; after 55 h, 36 mol% of the organic product was ether. 25 refs., 5 figs., 3 tabs.

  6. Preparation of carbon nanotubes by ethanol catalytic combustion technique using nickel salt as catalyst precursor

    Institute of Scientific and Technical Information of China (English)

    LI Fei; ZOU Xiao-ping; CHENG Jin; ZHANG Hong-dan; REN Peng-fei

    2006-01-01

    A simple growth technique of carbon nanotubes (CNTs) by combustion of ethanol was developed. In the experiment,copper plate was employed as substrate,nickel nitrate (Ni(NO3)2) and nickel chloride (NiCl2) as catalyst precursor,and ethanol as carbon source. The cleaned copper substrate was dipped into catalyst precursor solution for mounting catalyst precursor particles. The dip-coated substrate was then placed into ethanol flame for about 10 min after drying. The black wool-like production grown on copper plate was obtained. This route is called an ethanol catalytic combustion(ECC) process. The black powders were characterized by means of scanning electron microscopy(SEM),transmission electron microscopy(TEM),energy dispersive X-ray spectrometer(EDS) and Raman spectroscopy. The results show that the techique is much simpler and more economical to meet the future broader applications.

  7. Adsorption of heavy metal ion from aqueous solution by nickel oxide nano catalyst prepared by different methods

    Directory of Open Access Journals (Sweden)

    Amira M. Mahmoud

    2015-03-01

    Full Text Available Environmental pollution by heavy metal is arising as the most endangering tasks to both water sources and atmosphere quality today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. To limit the spread of the heavy metals within water sources, nickel oxide nanoparticles adsorbents were synthesized and characterized with the aim of removal of one of the aggressive heavy elements, namely; lead ions. Nano nickel oxide adsorbents were prepared using NaOH and oxalic acid dissolved in ethanol as precursors. The results indicated that adsorption capacity of Pb(II ion by NiO-org catalyst is favored than that prepared using NaOH as a precipitant. Nickel oxide nanoparticles prepared by the two methods were characterized structurally and chemically through XRD, DTA, TGA, BET and FT-IR. Affinity and efficiency sorption parameters of the solid nano NiO particles, such as; contact time, initial concentration of lead ions and the dosage of NiO nano catalyst and competitive adsorption behaviors were studied. The results showed that the first-order reaction law fit the reduction of lead ion, also showed good linear relationship with a correlation coefficient (R2 larger than 0.9.

  8. Effect of Preparation Methods on Al2O3 Supported CuO-CeO2-ZrO2 Catalysts for CO Oxidation

    Directory of Open Access Journals (Sweden)

    Gaurav Rattan

    2012-12-01

    Full Text Available To examine the effect of preparation methods, four catalyst samples having same composition (CuCe5.17Zr3.83Ox/g-Al2O3 (15wt% were prepared by four different methods for CO oxidation. The catalysts were prepared by co-impregnation, citric acid sol-gel, urea nitrate combustion and urea gelation co-precipitation methods, and characterized by BET, XRD, TGA/DSC and SEM. The The air oxidation of CO was carried out in a tubular fixed bed reactor under the following operating conditions: catalyst weight - 100 mg, temperature - ambient to 250 oC, pressure - atmospheric, 2.5% CO in air, total feed rate - 60 ml/min.  It was observed that the catalytic activity greatly influenced by the preparation methods. The highest activity of the catalyst prepared by the sol gel method appeared to be associated with its largest BET surface area. All the four catalysts were active for CO oxidation and did not show deactivation of catalytic activity for 50 hours of continuous runs. The ranking order of the preparation methods of the catalyst is as follows: sol-gel > co-impregnation > urea gelation > urea nitrate combustion. Copyright © 2012 by BCREC UNDIP. All rights reservedReceived: 14th June 2012, Revised: 8th September 2012, Accepted: 19th September 2012[How to Cite: G. Rattan, R. Prasad, R.C.Katyal. (2012. Effect of Preparation Methods on Al2O3 Supported CuO-CeO2-ZrO2 Catalysts for CO Oxidation. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 112-123. doi:10.9767/bcrec.7.2.3646.112-123] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.3646.112-123 ] | View in 

  9. RuO2 supported NaY zeolite catalysts: Effect of preparation methods on catalytic performance during aerobic oxidation of benzyl alcohol

    Science.gov (United States)

    Jung, Dasom; Lee, Sunwoo; Na, Kyungsu

    2017-10-01

    The effects of preparation method for RuO2 supported zeolite catalysts on the catalytic consequences during the aerobic oxidation of benzyl alcohol to benzaldehyde were investigated. Three preparation methods, i.e., (i) simultaneous crystallization of the zeolite framework in the presence of RuCl3 (Ru(SC)/NaY), (ii) post ion-exchange with RuCl3 on the zeolite framework (Ru(IE)/NaY), and (iii) post support of preformed Ru metal nanoparticles on the zeolite surface (Ru(PS)/NaY), were used to construct three different RuO2 supported NaY zeolite catalysts. The catalyst performance was investigated as functions of the reaction time and temperature, in correlation with the structural changes of the catalysts, as analyzed by X-ray diffraction (XRD). The results revealed that the catalytic consequences were dramatically affected by the preparation methods. Although similar conversion was achieved with all three catalysts, the turnover frequency (TOF) differed. The Ru(PS)/NaY catalyst exhibited the highest TOF (33-48 h-1), whereas the other catalysts produced much lower TOFs (9-12 h-1). The Ru(PS)/NaY catalyst also had the highest activation energy (Ea) of 48.39 kJ mol-1, whereas the Ru(SC)/NaY and Ru(IE)/NaY catalysts had Ea values of 18.58 and 24.11 kJ mol-1, respectively. Notably, the Ru(PS)/NaY catalyst yielded a significantly higher pre-exponential factor of 5.22 × 105 h-1, which is about 5 orders of magnitude larger than that of the Ru(SC)/NaY catalyst (7.15 × 100 h-1). This suggests that collision between benzyl alcohol and molecular oxygen was very intensive on the Ru(PS)/NaY catalyst, which explains the higher TOF of the Ru(PS)/NaY catalyst relative to the others in spite of the higher Ea value of the former. In terms of recyclability, the pristine crystallinity of the zeolite framework was maintained in the Ru(SC)/NaY catalyst and the RuO2 phase exhibited an insignificant loss of the initial activity up to three catalytic cycles, whereas Ru(PS)/NaY showed slight

  10. Single-crystalline C60 nanostructures by sonophysical preparation: tuning hollow nanobowls as catalyst supports for methanol oxidation.

    Science.gov (United States)

    Zhang, Yang; Jiang, Lang; Li, Hui; Fan, Louzhen; Hu, Wenping; Wang, Chunru; Li, Yongfang; Yang, Shihe

    2011-04-18

    Large-scale single-crystalline hollow nanobowls of pure C(60) were prepared by applying a sonophysical strategy in a binary organic solution. Through the simple adjustment of the concentration of the C(60) /m-xylene solution and the volume ratio of m-xylene to acetonitrile, C(60) nanorings, nanoplates, nanorods, and nanowires were also selectively synthesized. The promise of the C(60) hollow structures as Pt catalyst supports is heightened by the significantly enhanced catalytic activity toward methanol oxidation for a given amount of C(60) used, which demonstrates their potential application in fuel cells.

  11. The Comparison of Hydrochloric Acid and Phosphoric Acid Treatments in the Preparation of Montmorillonite Catalysts for RNA Synthesis

    Science.gov (United States)

    Aldersley, Michael Frank; Joshi, Prakash C.; Huang, Yixing

    2017-02-01

    The treatment of clay minerals with a preliminary acid wash and titration to pH 7 has proven to generate catalysts for the most interesting of oligomerization reactions in which activated RNA-nucleotides generate oligomers up to 40-mers. Significantly, not all clay minerals become catalytic following this treatment and none are catalytic in the absence of such treatment. The washing procedure has been modified and explored further using phosphoric acid and the outcomes are compared to those obtained when clay samples are prepared following a hydrochloric acid wash.

  12. Autothermal Reforming and Partial Oxidation of Methane in Fluidized Reactor over Highly Dispersed Ni Catalyst Prepared from Ni Complex

    Institute of Scientific and Technical Information of China (English)

    GAO Jing; HOU Zhao-Yin; SHEN Kai; LOU Hui; FEI Jin-Hua; ZHENG Xiao-Ming

    2006-01-01

    Highly dispersed Ni catalysts on spherical SiO2 were prepared by simple impregnation of Ni(acac)2, [Ni-(NH3)6-n(H2O)n]2+, [Ni(en)3]2+ and [Ni(EDTA)]2-. Pulse adsorption of H2 and TEM analysis results confirmed that Ni was dispersed very well on the surface of SiO2 even after calcination (4 h) and reduction (1 h) at high temperature of 800 ℃. These highly dispersed and uniquely sized Ni crystallites were more stable and more reactive for both autothermal reforming and partial oxidation of methane in fluidized reactor.

  13. Deposition-precipitation with Urea to prepare Au/Mg(OH){sub 2} catalysts: Influence of the preparation conditions on metal size and load

    Energy Technology Data Exchange (ETDEWEB)

    Milone, Candida, E-mail: cmilone@ingegneria.unime.it [Dipartimento di Chimica Industriale e Ingegneria dei Materiali, University of Messina, Messina, 98166 (Italy); Trapani, Mariachiara [Dipartimento di Chimica Industriale e Ingegneria dei Materiali, University of Messina, Messina, 98166 (Italy); Zanella, Rodolfo [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico, Mexico D.F., 04510 (Mexico); Piperopolulos, Elpida; Galvagno, Signorino [Dipartimento di Chimica Industriale e Ingegneria dei Materiali, University of Messina, Messina, 98166 (Italy)

    2010-12-15

    Deposition-precipitation with Urea method to prepare Au/Mg(OH){sub 2} was investigated. The preparation was carried out at 80 {sup o}C using an aqueous solution of HAuCl{sub 4} and Urea in presence of MgO as support precursor. The pH of the solution was 9.5-10 owing to the rapid hydration of MgO to Mg(OH){sub 2}. The influence of the preparation conditions (Urea concentration, preparation procedure, addition of magnesium citrate) on the gold load and particle size distribution was evaluated. The structural characterization of preparations was carried out by means of X-ray diffractometry and transmission electron microscopy. Among the parameters investigated, the preparation procedure, that is the control of the interaction between gold species and the support, is the main step for the deposition of the highest amount of gold (> 80% of the theoretical amount) having small size and a narrow distribution (d = 4.1 nm, {sigma} = {+-}1.1 nm). The synthesized catalysts were tested in the CO oxidation reaction.

  14. PREPARATION AND CHARACTERIZATION OF SPHERICAL PP/PB ALLOYS WITH MgCl2-SUPPORTED ZIEGLER-NATTA CATALYST

    Institute of Scientific and Technical Information of China (English)

    Ai-hua He; Yang-wei Shi; Guo-qing Liu; Wei Yao; Bao-chen Huang

    2012-01-01

    Polypropylene (PP)/polybutene-1 (PB) alloys within reactor were prepared by MgCl2-supported Ziegler-Natta catalyst with sequential two-stage polymerization technology.First,propylene homo-polymerizations were carried out to form isotactic polypropylene (iPP) particles containing active catalyst.Then,butene-1 was subsequently polymerized to form polybutene-1 phase inside the iPP particles.Finally,iPP/PB alloys with spherical shape and adjustable PB content were synthesized.The catalytic activity and catalytic stereospecificity of the Z-N catalyst in the two-stage polymerization process are discussed.The composition and physical properties of the PP alloys were characterized by FT-IR,13C-NMR,SEM,DSC and XRD.It was found that the in-reactor PP alloys are mainly composed of PP and PB with a little amount of poly(buteneco-propylene) random copolymers and poly(butene-block-propylene) block copolymers.SEM measurements verified that the PB phases with size in the range of 300-400 nm dispersed in the PP matrix uniformly.The incorporation of PB upon the PP matrix affects the properties of final products greatly.

  15. Preparation, characterization and catalytic properties of S2O82-/ZrOe-CeO2 solid superacid catalyst

    Institute of Scientific and Technical Information of China (English)

    FAN Guodong; SHEN Mao; ZHANG Zhao; JIA Farui

    2009-01-01

    A novel solid superacid catalyst S2O82-/ZrO2-CeO2 was prepared by a coprecipitation method and characterized by means of XRD, FTIR, BET, TEM and DSC/TG analysis methods. The results indicated that incorporation of appropriate amounts of Ce into the catalyst was beneficial to the formation of sole tetragonal ZrO2 and effectively prevented from the formation of monoclinic ZrO2, and restrained the loss of sulfated species. XRD revealed the presence of tetragonal Ceo0.16Zr0.84O2phase in the case of S2O82-/ZrO2-CeO2 calcined above 500 ℃. Catalytic activities of S2O82-/ZrO2-CEO2 for the estefification of lactic acid with n-butanol was studied. The results showed that the optimttrn conditions were as follows: calcination temperature of the catalyst 600 ℃, n(lactic acid):n(n-butyl alcohol)=1.0:3.0, w(S2O82-/ZrO2-CEO2)=12.0%, reaction temperature 145 ℃, and reaction time 2 h. The esterification efficiency of lactic acid was about 96.6%.

  16. Preparation of symmetric and asymmetric aromatic azo compounds from aromatic amines or nitro compounds using supported gold catalysts.

    Science.gov (United States)

    Grirrane, Abdessamad; Corma, Avelino; Garcia, Hermenegildo

    2010-03-01

    This protocol describes the aerobic oxidation of aromatic anilines to aromatic azo compounds using gold (Au) nanoparticles supported on TiO(2) as a catalyst. Yields above 98% are achieved under a few bars of oxygen pressure. It should be noted that the use of stoichiometric amounts of environmentally unfriendly reagents, e.g., transition metals and nitrites, commonly used in current syntheses of azo compounds, is avoided using this approach. The protocol is illustrated with the synthesis of parent azobenzene from aniline, and this reaction takes 22 h. Au on TiO(2) can also be used as a hydrogenation catalyst, making it possible to prepare azo compounds directly from nitroaromatics through a two-step (hydrogenation followed by aerobic oxidation), one-pot, one-catalyst reaction. In addition, the catalytic process is efficient for the synthesis of symmetric and a range of asymmetric aromatic azo compounds from the mixtures of two anilines substituted with electron-donor and electron-acceptor substituents.

  17. Size-Controlled Pd Nanoparticle Catalysts Prepared by Galvanic Displacement into a Porous Si-Iron Oxide Nanoparticle Host.

    Science.gov (United States)

    Kim, Taeho; Fu, Xin; Warther, David; Sailor, Michael J

    2017-02-21

    Porous silicon nanoparticles containing both Pd and iron oxide nanoparticles are prepared and studied as magnetically recoverable catalysts for organic reductions. The Pd nanoparticles are generated in situ by electroless deposition of Pd(NH3)4(2+), where the porous Si skeleton acts as both a template and as a reducing agent and the released ammonia ligands raise the local pH to exert control over the size of the Pd nanoparticles. The nanocomposites are characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, nitrogen adsorption, X-ray diffraction, superconducting quantum interference device magnetization, and dynamic light scattering. The nanocomposite consists of a porous Si nanoparticle (150 nm mean diameter) containing ∼20 nm pores, uniformly decorated with a high loading of surfactant-free Pd nanoparticles (12 nm mean diameter) and superparamagnetic γ-Fe2O3 nanoparticles (∼7 nm mean diameter). The reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride is catalyzed by the nanocomposite, which is stable through the course of the reaction. Catalytic reduction of the organic dyes methylene blue and rhodamine B is also demonstrated. The conversion efficiency and catalytic activity are found to be superior to a commercial Pd/C catalyst compared under comparable reaction conditions. The composite catalyst can be recovered from the reaction mixture by applying an external magnetic field due to the existence of the superparamagnetic iron oxide nanoparticles in the construct. The recovered particles retain their catalytic activity.

  18. Promotion Effect of Lantanum ions on Co/SiO2 Catalysts Prepared via Solvated Metal Atom Impregnation Method

    Institute of Scientific and Technical Information of China (English)

    吴世华; 张守民; 黄维平; 李保庆; 石娟

    2004-01-01

    In order to assess the promotional effects of La3+ on CO hydrogenation of Co/SiO2 catalyst, solvated metal atom impregnation (SMAI) method was used to prepare unpromoted 10% (mass fraction) Co/SiO2 and a series of La3+-promoted 10% (mass fraction) Co/SiO2 catalyst with different La/Co atomic ratios (0.1, 0.3, 0.5). X-ray diffraction (XRD), and CO chemisorption measurements show that the cobalt particle size decreases as the La/Co ratios increase. X-ray photoelectron spectrescopy indicates that cobalt is in zero-valent state for all the samples. Catalytic test shows that the catalytic activity of La3+-promoted Co/SiO2 in CO hydrogenation is higher than that of unpromoted Co/SiO2, and enhances with the La/Co ratios increase. La3+ promotion also causes the enhanced selectivity of Co/SiO2 catalyst for higher hydrocarbon products.

  19. Unsupported NiPt alloy metal catalysts prepared by water-in-oil (W/O) microemulsion method for methane cracking

    KAUST Repository

    Zhou, Lu

    2016-05-18

    Unsupported NiPt metal catalyst with Ni/Pt molar ratio of 88/12 is prepared by water-in-oil (W/O) microemulsion method in this study. Compared to monometallic Ni and Pt catalysts, the NiPt catalyst exhibits superior activity and stability for methane cracking. By XRD (X-ray powder diffraction), XPS (X-ray photoelectron spectroscopy) and TEM (Transmission electron microscopy) analyses, the formation of Ni(0)Pt(0) alloy is believed to be the main reason for the reactivity improvement of this catalyst. Carbon nano tube (CNT) with Ni(0)Pt(0) particles anchored on the top of tube are found for the NiPt catalyst. © 2016 Elsevier Ltd.

  20. PREPARATION AND CATALYTIC ACTIVITY FOR ISOPROPYL BENZENE CRACKING OF Co, Mo AND Co/Mo-Al2O3-PILLARED MONTMORILLONITE CATALYSTS

    Directory of Open Access Journals (Sweden)

    Hasanudin Hasanudin

    2010-06-01

    Full Text Available It has been prepared Co, Mo and Co/Mo-Al2O3-pillared montmorillonite catalysts using montmorillonite clay  as raw material. The structure and porosity of the catalysts were determined using N2 adsorption-desorption and FT-IR spectroscopy analysis methods. Isopropyl benzene cracking using these catalysts were used to test the catalytic activity and performance of Co, Mo and Co/Mo-Al2O3-pillared montmorillonites.  Characterization results showed that pillarization resulted in the increase of the total pore volume and specific surface area of the clay. Meanwhile, transition metals (Co, Mo and Co/Mo loaded on Al2O3-pillared monmorillonites could increase the catalytic activity of the catalysts for isopropyl benzene cracking significantly.   Keywords: pillared monmorillonite, isopropyl benzene  and cracking catalyst

  1. HDS and deep HDS activity of CoMoS-mesostructured clay catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Carrado, K.A.; Castagnola, N. [Chemistry Division, 9700 S. Cass Avenue, Argonne National Laboratory, Argonne, IL 60439 (United States); Kim, J.H.; Song, C.S. [Clean Fuels and Catalysis Program, The Energy Institute and Department of Energy and Geo-Environmental Engineering, 206 Hosler Building, Pennsylvania State University, University Park, PA 16802 (United States); Marshall, C.L.; Schwartz, M.M. [Chemical Engineering Division, 9700 S. Cass Avenue, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2006-09-15

    The goal of this work is to identify more promising supports from synthetic clay materials to advance hydrotreating catalyst development. Silica sol can be used as the silicon-containing starting material when creating nanoporous layered silicate catalysts with a certain portion of unreacted sol particles incorporated into the final matrix. The resulting structure then has mesoporosity and a unique morphology. Hectorite-based clays have been prepared using different silica sols in order to ascertain the importance of sol characteristics on the final matrix. Several techniques have been applied to characterize the materials, including XRD, TGA, N{sub 2} porosimetry, and TEM. For hydrodesulfurization (HDS), the conversion of dibenzothiophene (DBT) to biphenyl was examined at 400{sup o}C using CoMoS-loaded mesostructured clay supports. No hydrogenation or hydrocracking was observed with any of the clay supports. The most active clay was derived from Ludox silica sol AS-30 with an activity of 65% DBT conversion and 100% selectivity to biphenyl (BP). For comparison, a reference commercial catalyst displayed 94% BP selectivity. For deep HDS, the conversion of 4,6-dimethyldibenzothiophene was tested at 325 and 350{sup o}C. At 325{sup o}C, conversions are 92% of commercial catalysts for a CoMoS-loaded mesostructured clay derived from Ludox AM-30 silica sol. A commercially available synthetic hectorite called laponite has very low activity, indicating that the unique morphology of the mesostructured clays is important. Hydrogenolysis vs. hydrogenation pathways are compared for the deep HDS reaction. HR-TEM of the most active deep HDS catalyst revealed a multilayered MoS{sub 2} morphology. (author)

  2. Controlled metal nitrate decomposition for the preparation of supported metal Catalysts

    NARCIS (Netherlands)

    Wolters, M.

    2010-01-01

    High surface area supported metal (oxide) catalysts are essential for the production of fuels, chemicals, pharmaceuticals and the abatement of environmental pollution. Impregnation of high surface area supports, often silica or alumina, followed by drying, calcination and reduction is one of the

  3. Permanganic acid: a novel precursor for the preparation of manganese oxide catalysts

    NARCIS (Netherlands)

    C. Kappenstein; T. Wahdan; D. Duprez; M.I. Zaki; D. Brands; E. Poels; A. Bliek

    1994-01-01

    Unsupported and ψ-alumina supported MnOx catalysts (1-10 wt-% Mn) were preparedfrom aqueous solutions of HMnO4 and compared with nitrate based samples. They were characterized by XRD, XPS, BET area, oxygen storage capacity and by their catalytic behaviour versus ammonia DeNOx reaction. The unsupport

  4. Preparation of Mg-doped Ce-Zr Solid Catalysts and Their Catalytic ...

    African Journals Online (AJOL)

    NICO

    Addition of MgO to the Ce-Zr mixed metal oxides affected both particle size and catalytic activity. KEYWORDS ... effect on vascular smooth muscle.6 2,4-TZD has an active methy- ... catalytic properties and for a given reaction the activity and selectivity of the ... heterogeneous catalysts for fine chemical synthesis under green.

  5. Sulfamic Acid as a Green and Reusable Catalyst for the Preparation of β-Enaminones

    Institute of Scientific and Technical Information of China (English)

    WANG, Lei; LU, Xiaohua; AN, Litao; ZOU, Jianping

    2009-01-01

    Sulfamic acid can effectively catalyze the reaction of β-diketones with arylamines to afford the β-enaminones. The present method offers several advantages, such as high yield, short reaction time, mild conditions, easy work-up and catalyst recyclability.

  6. The curious case of zeolite-clay/binder interactions and their consequences for catalyst preparation

    NARCIS (Netherlands)

    Whiting, Gareth T; Chowdhury, Abhishek Dutta|info:eu-repo/dai/nl/412438003; Oord, R.; Paalanen, Pasi|info:eu-repo/dai/nl/370602013; Weckhuysen, Bert M|info:eu-repo/dai/nl/285484397

    2016-01-01

    Zeolite-based catalyst bodies are commonly employed in a range of important industrial processes. Depending on the binder and shaping method chosen, vast differences in the reactivity, selectivity and stability are obtained. Here, three highly complementary micro-spectroscopic techniques were

  7. Conversion of furan derivatives for preparation of biofuels over Ni-Cu/C catalyst

    DEFF Research Database (Denmark)

    Fu, Zhaolin; Wang, Z.; Lin, Weigang

    2017-01-01

    Conversions of furfural and 5-hydroxymethylfurfural as model components in bio-oil were investigated over Ni-Cu/C catalyst with formic acid as hydrogen donor in isopropanol solvent to produce biofuels. The effects of reaction temperature, feed ratio, and reaction time were studied. A high yield...... biofuels from furan derivatives....

  8. Controlled metal nitrate decomposition for the preparation of supported metal Catalysts

    NARCIS (Netherlands)

    Wolters, M.

    2010-01-01

    High surface area supported metal (oxide) catalysts are essential for the production of fuels, chemicals, pharmaceuticals and the abatement of environmental pollution. Impregnation of high surface area supports, often silica or alumina, followed by drying, calcination and reduction is one of the mos

  9. Influence of double promotion on HDS catalysts prepared by urea-matrix combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Cortes, Sergio L. [Laboratorio de Cinetica y Catalisis, Departamento de Quimica, Facultad de Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela); Xiao, Tian-Cun; Lin, Tsung-Wu; Green, Malcolm L.H. [Wolfson Catalysis Centre, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom)

    2006-04-11

    The stringent environmental regulations in the US, Japan and Europe are requiring significant improvement in the quality of transportation fuels. A new strategy based on urea-matrix combustion method for the synthesis of alumina-supported molybdate-based mixed oxides (i.e., bimetallic and trimetallic oxides) has been applied. This permits to control the alumina-mixed oxide interaction and therefore the HDS catalytic behaviour. The oxidic and sulfurized states of the HDS catalysts were characterized by X-ray diffraction (XRD), laser Raman spectroscopy (LRS), temperature-programmed reduction (TPR) and high resolution transmission electron microscopy (HRTEM). Catalyst performance was evaluated using a tubular fixed-bed reactor and the hydrodesulfurization of thiophene under normal pressure as model reaction. It has been found that Ni-promoted alumina-supported MoO{sub 3} catalyst precursor presented a non well-ordered structure of Ni-Mo phase supported on alumina surface. However, when cobalt was added to Ni-Mo precursor the {beta}-isomorph stability was significantly improved and the formation of alumina-supported {beta}-Co{sub 0.5}Ni{sub 0.5}MoO{sub 4} was observed. The activation treatments markedly affect the catalyst structure and hence the HDS catalytic performance. The catalyst series pretreated in H{sub 2}S-H{sub 2} was 2-3 times more active than those C{sub 4}H{sub 4}S-H{sub 2}-pretreated catalysts and ca. 2-10 times more active than the pre-reduced samples. A significantly greater HDS activity of H{sub 2}S-H{sub 2}-pretreated Co{sub 0.5}Mg{sub 0.5}MoS{sub x}/{gamma}-Al{sub 2}O{sub 3} catalyst was observed, which is attributed to the fact that both promoters are into the same network interacting directly with the molybdenum. This feature hinders not only the segregation of cobalt sulfide, but also the formation of long MoS{sub 2} slabs. (author)

  10. Ni/SiO2 Catalyst Prepared with Nickel Nitrate Precursor for Combination of CO2 Reforming and Partial Oxidation of Methane: Characterization and Deactivation Mechanism Investigation

    OpenAIRE

    Sufang He; Lei Zhang; Suyun He; Liuye Mo; Xiaoming Zheng; Hua Wang; Yongming Luo

    2015-01-01

    The performance of Ni/SiO2 catalyst in the process of combination of CO2 reforming and partial oxidation of methane to produce syngas was studied. The Ni/SiO2 catalysts were prepared by using incipient wetness impregnation method with nickel nitrate as a precursor and characterized by FT-IR, TG-DTA, UV-Raman, XRD, TEM, and H2-TPR. The metal nickel particles with the average size of 37.5 nm were highly dispersed over the catalyst, while the interaction between nickel particles and SiO2 support...

  11. Highly-dispersed Ta-oxide catalysts prepared by electrodeposition in a non-aqueous plating bath for polymer electrolyte fuel cell cathodes

    KAUST Repository

    Seo, Jeongsuk

    2012-01-01

    The Ta-oxide cathode catalysts were prepared by electrodeposition in a non-aqueous solution. These catalysts showed excellent catalytic activity and have an onset potential of 0.92 V RHE for the oxygen reduction reaction (ORR). The highly-dispersed Ta species at the nanometer scale on the carbon black was an important contributor to the high activity. © 2012 The Royal Society of Chemistry.

  12. Pd Close Coupled Catalyst

    Institute of Scientific and Technical Information of China (English)

    Zhong Hua SHI; Mao Chu GONG; Yao Qiang CHEN

    2006-01-01

    A catalyst comprised novel high surface area alumina support was prepared to control emission of automobiles. The results showed that prepared catalyst could satisfy the requirements of a high performance close coupled catalyst for its good catalytic activity at low temperature and good stability at high temperature.

  13. New catalyst supports prepared by surface modification of graphene- and carbon nanotube structures with nitrogen containing carbon coatings

    Science.gov (United States)

    Oh, Eun-Jin; Hempelmann, Rolf; Nica, Valentin; Radev, Ivan; Natter, Harald

    2017-02-01

    We present a new and facile method for preparation of nitrogen containing carbon coatings (NCC) on the surface of graphene- and carbon nanotubes (CNT), which has an increased electronic conductivity. The modified carbon system can be used as catalyst support for electrocatalytic applications, especially for polymer electrolyte membrane fuel cells (PEMFC). The surface modification is performed by impregnating carbon structures with a nitrogen containing ionic liquid (IL) with a defined C:N ratio, followed by a thermal treatment under ambient conditions. We investigate the influence of the main experimental parameters (IL amount, temperature, substrate morphology) on the formation of the NCC. Additionally, the structure and the chemical composition of the resulting products are analyzed by electron microscopic techniques (SEM, TEM), energy disperse X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS) and hot extraction analysis. The modified surface has a nitrogen content of 29 wt% which decreases strongly at temperatures above 600 °C. The new catalyst supports are used for the preparation of PEMFC anodes which are characterized by polarization measurements and electrochemical impedance spectroscopy (EIS). Compared to unmodified graphene and CNT samples the electronic conductivity of the modified systems is increased by a factor of 2 and shows improved mass transport properties.

  14. Evaluation of SiO2 sonogels, prepared by a new catalyst-free method, as drug delivery system.

    Science.gov (United States)

    Piñón-Segundo, Elizabeth; Ganem-Quintanar, Adriana; Flores-Flores, José Ocotlán; Saniger-Blesa, José Manuel; Urbán-Morlán, María Zaida; Mendoza-Romero, Luis; Nava-Arzaluz, María Guadalupe; Quintanar-Guerrero, David

    2008-08-01

    Recently, we reported on the synthesis of catalyst-free SiO(2) sonogels prepared by the sonication of a neutral distilled water/ tetraethyl ortosilicate mixture. The purpose of the present study was to evaluate the feasibility of using these sonogels as pharmaceutical delivery systems. A certified color additive (sunset yellow, SY) was used as a model compound for the release experiments. Different amounts of dye were incorporated into the gels before drying. Sonogels were characterized by scanning electron microscopy and differential scanning calorimetry. The effect of three drying temperatures (25 degrees C, 40 degrees C and 80 degrees C) and two mean grain sizes (1125 and 630 microm) on release behavior was analyzed. The analysis of variance showed no significant differences between the Higuchi's constants (K(H)) obtained for SY-loaded sonogels dried at 80 degrees C with different SY loads, irrespective of the mean grain size. In contrast, for SY-loaded sonogels dried at 40 degrees C, differences were found between sonogels loaded with 2.7, 7.7, 12.2, and 18.2% of SY, and no significant differences were detected between the mean grain sizes analyzed. Considering that the preparation of sonogels by the catalyst-free method allows an easy encapsulation, sonogels may offer an interesting alternative for drug release in the pharmaceutical field.

  15. Novel bimetallic dispersed catalysts for temperature-programmed coal liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Chunshan, Song; Kirby, S.; Schmidt, E. [Pennsylvania State Univ., University Park, PA (United States)] [and others

    1995-12-31

    The objective of this project is to explore bimetallic dispersed catalysts for more efficient coal liquefaction. Coal liquefaction involves cleavage of methylene, dimethylene and ether bridges connecting various aromatic units and the reactions of various oxygen functional groups. This paper describes recent results on (1) hydrodeoxygenation of O-containing polycyclic model compounds using novel organometallic catalyst precursors; and (2) activity and selectivity of dispersed Fe catalysts from organometallic and inorganic precursors for hydrocracking of 4-(1-naphthylmethyl) bibenzyl. The results showed that some iron containing catalysts have higher activity in the sulfur-free form, contrary to conventional wisdom. Adding sulfur to Fe precursors with Cp-ligands decreased the activity of the resulting catalyst. This is in distinct contrast to the cases with iron pentacarbonyl and superfine Fe{sub 2}O{sub 3}, where S addition increased their catalytic activity substantially. A positive correlation between sulfur addition and increased activity can be seen, but a reversed trend between Fe cluster size and hydrocracking conversion could be observed, for carbonyl-type Fe precursors. It is apparent that the activity and selectivity of Fe catalysts for NMBB conversion depends strongly on both the type of ligand environment, the oxidation state and the number of intermetal bonds in the molecular precursor.

  16. Ru promoted cobalt catalyst on γ-Al{sub 2}O{sub 3}: Influence of different catalyst preparation method and Ru loadings on Fischer–Tropsch reaction and kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Parnian, Mohammad Javad; Taheri Najafabadi, Ali [Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box 11155/4563, Tehran (Iran, Islamic Republic of); Mortazavi, Yadollah, E-mail: mortazav@ut.ac.ir [Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box 11155/4563, Tehran (Iran, Islamic Republic of); Oil and Gas Processing Center of Excellence, University of Tehran, P.O. Box 11155/4563, Tehran (Iran, Islamic Republic of); Khodadadi, Abbas Ali [Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box 11155/4563, Tehran (Iran, Islamic Republic of); Oil and Gas Processing Center of Excellence, University of Tehran, P.O. Box 11155/4563, Tehran (Iran, Islamic Republic of); Nazzari, Idin [Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box 11155/4563, Tehran (Iran, Islamic Republic of)

    2014-09-15

    Highlights: • Effect of impregnation order and Ru content on FT reaction is reported. • Co-impregnation of Co and Ru on Al{sub 2}O{sub 3} resulted in an improved reducibility of Co. • CoRu/Al{sub 2}O{sub 3} prepared by co-impregnation method showed a better catalytic performance. • Ru does not affect C{sub 5+} selectivity whereas the activity is enhanced considerably. • Effect of synthesis parameter on rate constant and activation energy is reported. - Abstract: Ruthenium promoted cobalt catalysts supported on γ-Al{sub 2}O{sub 3} were prepared by stepwise and co-impregnation methods. The effects of impregnation order on activity and selectivity of the Fischer–Tropsch synthesis (FTS) were investigated using fixed bed microreactor. The catalysts were characterized by TPR, XRD and TEM. The selected Ru loading was 0.15 wt.% while that of Co was 15.0 wt.% in all of the prepared samples by different order of impregnation. The catalyst prepared by co-impregnation method shifted both steps of cobalt oxide reduction temperatures to lower temperatures by about 100 °C. However, temperature shift was lower for the catalyst prepared by stepwise impregnation method. The highest CO conversion and C{sub 5+} selectivity and the lowest methane selectivity were obtained for the catalyst synthesized by co-impregnation method. Two other catalysts with 0.3 and 0.6 wt.% of Ru loadings on 15.0 wt.% Co were synthesized by co-impregnation and its effect on the FTS was investigated. The prepared catalysts showed an increase in CO conversion with the increase of Ru from 0 to 0.30 wt.%. However, further increase in Ru led to lower CO conversion for a Ru loading of 0.6 wt.%. The effects of temperature and H{sub 2}/CO ratio for all catalysts were examined and their performance modeled by a Langmuir–Hinshelwood–Hougen–Watson (LHHW) rate expression.

  17. Supported organoiridium catalysts for alkane dehydrogenation

    Science.gov (United States)

    Baker, R. Thomas; Sattelberger, Alfred P.; Li, Hongbo

    2013-09-03

    Solid supported organoiridium catalysts, a process for preparing such solid supported organoiridium catalysts, and the use of such solid supported organoiridium catalysts in dehydrogenation reactions of alkanes is provided. The catalysts can be easily recovered and recycled.

  18. High surface area ThO.sub.2 catalyst and method of preparing it

    Science.gov (United States)

    Colmenares, Carlos A.; Somorjai, Gabor A.; Maj, Joseph J.

    1985-01-01

    A ThO.sub.2 catalyst having a high surface area of about 80-125 m.sup.2 /g is synthesized. The compound is synthesized by simultaneously mixing an aqueous solution of ThNO.sub.3 (NO.sub.3).sub.4.4H.sub.2 O with an aqueous solution of Na.sub.2 CO.sub.3.H.sub.2 O, to produce a solution and solid ThOCO.sub.3. The solid ThOCO.sub.3 is separated from the solution, and then calcined at a temperature of about 225.degree.-300.degree. C. for about 40-55 hours to produce ThO.sub.2. The ThO.sub.2 catalyst produced includes Na present as a substitutional cation in an amount equal to about 5-10 atom percent.

  19. PREPARATION OF NOVEL POLYETHYLENE-graft- POLY(4-VINYLPYRIDINE)-SUPPORTED METALLOCENE CATALYSTS FOR ETHYLENE POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Ning Zhu; Yong Chen; Zi-long Li; Yuan-xia Liu; Yu-cai Ke; Wen-Hua Sun

    2003-01-01

    Polyethylene (PE) grafting 4-vinylpyridine copolymers has been produced as powders of different rushes by the irradiation method. After treatment with methylaluminoxane (MAO), the copolymers were used as supports for Cp2ZrCl2 catalyst. Results of X-ray photoelectron spectroscopy, Fourier transforms infrared spectroscopy, ultraviolet spectroscopy and scanning electron microscope measurements show that the catalytic sites have been linked through MAO on the PE-graft-4-vinylpyridine (PEVP). The percentages of grafting 4-vinylpyridine and supported Cp2ZrCl2 depend on the size of polyethylene powder. The smaller the polyethylene powder, the more percent of 4-vinylpyridine groups and Cp2ZrCl2 exist on the polyethylene chains, and the PEVP-supported catalyst has a relatively high activity for ethylene polymerization.

  20. A simple granulation technique for preparing high-porosity nano copper oxide(Ⅱ) catalyst beads

    Institute of Scientific and Technical Information of China (English)

    Seyed Javad Ahmadia; Mohammad Outokesh; Morteza Hosseinpour; Tahereh Mousavand

    2011-01-01

    A simple and efficient method was developed for fabricating spherical granules of CuO catalyst via a three-step procedure.In the first step,copper oxide nanoparticles were synthesized by hydrothermal decomposition of copper nitrate solution under supercritical condition.Then,they were immobilized in the polymeric matrix of calcium alginate,and followed by high-temperature calcination in an air stream as the third step,in which carbonaceous materials were oxidized,to result in a pebble-type catalyst of high porosity.The produced CuO nanoparticles were characterized by transmission electron microscopy (TEM) that revealed an average size of 5 nm,X-ray diffractometry (XRD),and thermo gravimetric (TG)analysis.The catalysts were further investigated by BET test for measurement of their surface area,and by temperature-programmed reduction analysis (H2-TPR) for determination of catalytic activity.The results demonstrated that immobilization of the CuO nanoparticle in the polymeric matrix of calcium alginate,followed by calcination at elevated temperatures,could result in notable mechanical strength and enhanced catalytic activity due to preservation of the high surface area,both valuable for practical applications.

  1. Functionalized dicationic ionic liquids: Green and efficient alternatives for catalysts in phthalate plasticizers preparation

    Indian Academy of Sciences (India)

    NEGAR ZEKRI; REZA FAREGHI-ALAMDARI; ZAHRA KHODARAHMI

    2016-08-01

    Two highly acidic, imidazolium-based, functionalized dicationic ionic liquids (FDCILs) were synthesized and characterized by FTIR, ¹H NMR and¹³ C NMR. The synthesized FDCILs were used as efficient and green catalysts in the synthesis of phthalate plasticizers through esterification of phthalic anhydride (PhA)with ethanol, n-propanol and n-butanol. Among these two FDCILs, (dimethyl-4-sulfobutyl-ammonium) 1,2- ethan-1-methyl-imidazolium-sulfonic acid hydrogen sulfate performed better. The catalytic activity of FDCIL is related to the density of acidic groups on it and the length of the carbon chain in the cationic part. Theinfluences of the reaction temperature, catalyst dosage, and molar ratio of phthalic anhydride to alcohol on the esterification reaction were investigated. The reusability of the catalyst in these reactions was studied too. Theb diester phthalates were obtained up to 98.8% yield. The products can be separated easily by decantation from the reaction mixture.

  2. Novel low-cost Fenton-like layered Fe-titanate catalyst: preparation, characterization and application for degradation of organic colorants.

    Science.gov (United States)

    Chen, Yongzhou; Li, Nian; Zhang, Ye; Zhang, Lide

    2014-05-15

    Novel low-cost layered Fe-titanate catalyst for photo-Fenton degradation of organic contaminants was successfully developed by ion exchange of Fe(3+) with Na(+) layered nano Na-titanates which was prepared by alkali hydrothermal method. The as prepared materials were characterized by powder X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectrometer (EDX). The catalytic activity of the Fe-titanate catalyst was evaluated by the decolorization of three different dyes (rhodamine 6G (R6G), methyl blue (MB), and methyl orange (MO)) under UV irradiation at room temperature. Effect of several important factors such as Fe loading in the catalyst, initial solution pH, catalyst dosage, H2O2 amount, and reaction time was systematically studied. It was found that the decolorization was very efficient for all three dyes. The efficiency reached 98% for R6G, 98.5% for MB, and 97% for MO, respectively, under optimal conditions. The oxidation process was quick, and only 15 min is needed for all three dyes. Moreover, the Fe-titanate catalyst could be used in a wider and near neutral pH range compared with classic Fenton systems which need to be operated at around pH 3.0. Kinetic analysis results showed that the oxidation kinetics was accurately represented by pseudo-first-order model. More importantly, the catalyst was very stable and could be reused for at least four cycles when operated under near neutral pH. The Fe leaching from the catalyst measured was almost negligible, which not only demonstrated the stability of the catalyst, but also avoided the formation of secondary Fe pollution. Therefore, the reported Fe-titanates are promising nanomaterials which can be used as Fenton like catalyst for the degradation of organic contaminant in wastewater.

  3. Preparation and characterization of high photoactive TiO2 catalyst using the UV irradiation-induced sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Jianhua Liu; Rong Yang; Songmei Li

    2006-01-01

    High photoactive TiO2 catalyst was prepared using the sol-gel method through UV irradiation during the formation stage of nuclei. The surface morphology and microstructure of the prepared catalyst were characterized using scanning electron microscopy(SEM), X-ray diffraction patterns (XRD), and Fourier transform infrared spectroscopy (FT-IR). The photoactivity was evaluated by the degradation of methylene blue. The results show that the photocatalysis of the prepared catalyst is higher than that of conventional heat-treated particles. The higher photoactivity is a combined result of favorable microstructure, appropriate hydroxyl groups, and active sites of Ti3+ ions on the surface of TiO2. It is concluded that the ultraviolet irradiation-induced sol-gel method is an effective method to enhance the photocatalysis of TiO2.

  4. Low-temperature selective catalytic reduction of NO on CeO2-CuO/Al2O3 catalysts prepared by different methods.

    Science.gov (United States)

    Guo, Rui-Tang; Zhen, Wen-Long; Pan, Wei-Guo; Hong, Jie-Nan; Jin, Qiang; Ding, Cheng-Gang; Guo, Shi-Yi

    2014-08-01

    CeO2-CuO/Al2O3 catalysts were prepared by three different methods and their activities for selective catalytic reduction (SCR) of NO with NH3 were investigated. As can be seen from the experimental results, the catalyst prepared by the single-step sol-gel (SG) method showed the best SCR activity and resistance to SO2 and H2O. In order to investigate the relationship between the preparation method and the performance of SCR catalysts, the catalysts were characterized by using Brunauer-Emmett-Teller, X-ray diffraction, temperature programmed reduction with hydrogen, temperature programmed desorption with ammonia, X-ray photoelectron spectroscopy, Fourier transform infrared and thermo-gravimetric analysis techniques. It was found that the excellent performance of CeO2-CuO/Al2O3 catalyst prepared by the single-step SG method should be resulted from its large surface area, low crystallinity, high oxygen storage capacity, high NH3 adsorption capacity, high concentration of surface chemisorbed oxygen, weak sulphation process and weak water absorption.

  5. Comparative Study of Various Preparation Methods of CuO–CeO2 Catalysts for Oxidation of n–Hexane and iso–Octane

    Directory of Open Access Journals (Sweden)

    Ashutosh Mishra

    2013-03-01

    Full Text Available The complete oxidation of n-Hexane and iso-Octane was studied individually in a fixed bed tubular flow reactor over CuO-CeO2 catalysts synthesized via four different methods namely urea-nitrate combustion method, urea gelation/co-precipitation method, citric acid sol-gel method and co-impregnation method. Laser diffraction was employed in catalysts characterization. The results obtained from the complete conversion of n-Hexane and iso-Octane revealed that the CuO-CeO2 catalysts prepared by urea-nitrate combustion method (UNC showed the best performance than the catalysts prepared by other methods used in the present investigation. CuO-CeO2 catalysts prepared by UNC method achieve total n-Hexane and iso-Octane conversion to CO2 at lower temperatures of 280 0C and 340 0C respectively due to the larger surface area of the catalysts which increases the specific rate of reaction. © 2013 BCREC UNDIP. All rights reservedReceived: 30th October 2012; Revised: 30th November 2012; Accepted: 3rd December 2012[How to Cite: A. Mishra, B.D. Tripathi, A.K. Rai, R. Prasad (2013. Comparative Study of Various Preparation Methods of CuO–CeO2 Catalysts for Oxidation of n–Hexane and iso–Octane. Bulletin of Chemical Reaction Engineering & Catalysis, 7(3: 172-178. (doi:10.9767/bcrec.7.3.4076.172-178][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.7.3.4076.172-178 ] View in  |

  6. The effect of preparation method on the performance of PtSn/Al2O3 catalysts for acetic acid hydrogenation

    Directory of Open Access Journals (Sweden)

    Zhang Ke

    2015-03-01

    Full Text Available PtSn/Al2O3 catalysts with a given loading of 1 wt% Pt and 1 wt% Sn were prepared by co-impregnation or successive impregnation with aqueous solutions of Pt, Sn precursors and a commercial alumina. The catalysts were characterized by N2 adsorption, H2-TPR (H2 temperature-programmed reduction, H2-pulse chemisorption, XPS (X-ray photoelectron spectroscopy and CO-FTIR (Fourier transform infrared spectroscopy, and tested in the hydrogenation of acetic acid. The results showed that the preparation method affected both the chemical properties and their performance in the hydrogenation of acetic acid. Sn enrichment on the catalysts surface was observed on the co-impregnated catalyst and catalyst in which the Pt precursor had been loaded first. It was found that the modification of Pt was a function of the sequence of Sn addition as revealed by CO-FTIR. Co-impregnated catalyst showed the highest activity and ethanol selectivity.

  7. Preparation and characterizations of highly dispersed carbon supported PdxPty/C catalysts by a modified citrate reduction method for formic acid electrooxidation

    Science.gov (United States)

    Li, Zuopeng; Li, Muwu; Han, Mingjia; Zeng, Jianhuang; Li, Yuexia; Guo, Yanqin; Liao, Shijun

    2014-05-01

    Carbon supported PdxPty/C (atomic ratio x:y from 1:1 to 6:1) have been prepared by a modified citrate reduction method assisted by inorganic stabilizers. Without using high molecular capping agents as stabilizers, the PdxPty/C catalysts are highly dispersed on the carbon support and no particle aggregations are found for the PdxPty/C catalysts. X-ray photoelectron spectroscopy reveals either Pt or Pd segregation for the PdxPty/C catalysts depending on Pd/Pt atomic ratio. CO stripping in 0.5 M H2SO4 and repeated formic acid oxidation cyclic voltammetry in 0.5 M HCHO + 0.5 M H2SO4 have been conducted to test out the CO tolerance and stability of the catalysts, respectively. It has been found that, with the increase of Pd/Pt atomic ratio, the CO stripping peak potential increases (less CO tolerant), whereas the catalyst stability towards formic acid oxidation decreases. The as-prepared catalysts reveal excellent mass-normalized formic acid oxidation activity as compared with published results possibly due to high dispersion and the absence of high molecular capping agents.

  8. Atmospheric-Pressure DBD Cold Plasma for Preparation of High Active Au/P25 Catalysts for Low-Temperature CO Oxidation

    Institute of Scientific and Technical Information of China (English)

    DI Lanbo; ZHAN Zhibin; ZHANG Xiuling; QI Bin; XU Weijie

    2016-01-01

    Cold plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure was adopted for preparation of commercial TiO2 Degussa P25 supported Au catalysts (Au/P25-P) with the assistance of the deposition-precipitation procedure.The influences of the plasma reduction time and calcination on the performance of the Au/P25-P catalysts were investigated.CO oxidation was performed to investigate the catalytic activity of thc Au/P25 catalysts.The results show that DBD cold plasma for the fabrication of Au/P25-P catalysts is a fast process,and Au/P25-P (4 min) exhibited the highest CO oxidation activity due to the complete reduction of Au compounds and less consumption of oxygen vacancies.In order to form more oxygen vacancies active species,Au/P25-P was calcined to obtain Au/P25-PC catalysts.Interestingly,Au/P25-PC exhibited the highest activity for CO oxidation among the Au/P25 samples.The results of transmission electron microscopy (TEM) indicated that the smaller size and high distribution of Au nanoparticles are the mean reasons for a high performance of Au/P25-PC.Atmospheric-pressure DBD cold plasma was proved to be of great efficiency in preparing high performance supported Au catalysts.

  9. DEVELOPMENT OF NEW TYPE ALUMINIUM OXIDE MATRIX CATALYST FOR PREPARATION OF SULFUR%新型氧化铝基制硫催化剂的研制

    Institute of Scientific and Technical Information of China (English)

    商剑峰; 刘爱华; 罗保军; 刘剑利

    2012-01-01

    The paper described the development, characterization and activity valuation of LS -02 new type aluminium oxide matrix catalyst for preparation of sulfur. The LS -02 catalyst was prepared by rotation shaping process and aluminium oxide as main raw material. Compared with LS -300 catalyst, the LS -02 catalyst possessed higher specific surface area, larger pore volume, more reasonable distribution of pore size and higher Claus and hydrolyzation reactivity. Comprehensive properties of the LS -02 catalyst reached foreign similar catalyst.%介绍了LS-02新型氧化铝制硫催化剂的研制、表征及活性评价。该催化剂以氧化铝为主要原料,采用转动成型工艺制备。该催化剂较LS-300催化剂具有更高的比表面积、更大的孔体积、更合理的孔分布及更高的克劳斯活性和水解活性,综合性能达到国外同类催化剂水平。

  10. Synthesis and Electrochemical Evaluation of Carbon Supported Pt-Co Bimetallic Catalysts Prepared by Electroless Deposition and Modified Charge Enhanced Dry Impregnation

    Directory of Open Access Journals (Sweden)

    John Meynard M. Tengco

    2016-06-01

    Full Text Available Carbon-supported bimetallic Pt-Co cathode catalysts have been previously identified as higher activity alternatives to conventional Pt/C catalysts for fuel cells. In this work, a series of Pt-Co/C catalysts were synthesized using electroless deposition (ED of Pt on a Co/C catalyst prepared by modified charge enhanced dry impregnation. X-ray diffraction (XRD and scanning transmission electron microscopy (STEM characterization of the base catalyst showed highly dispersed particles. A basic ED bath containing PtCl62− as the Pt precursor, dimethylamine borane as reducing agent, and ethylenediamine as stabilizing agent successfully targeted deposition of Pt on Co particles. Simultaneous action of galvanic displacement and ED resulted in Pt-Co alloy formation observed in XRD and energy dispersive X-ray spectroscopy (XEDS mapping. In addition, fast deposition kinetics resulted in hollow shell Pt-Co alloy particles while particles with Pt-rich shell and Co-rich cores formed with controlled Pt deposition. Electrochemical evaluation of the Pt-Co/C catalysts showed lower active surface but much higher mass and surface activities for oxygen reduction reaction compared to a commercial Pt/C fuel cell catalyst.

  11. Preparation,Characterization of CuO/CeO2 and Cu/CeO2 Catalysts and Their Applications in Low-Temperature CO Oxidation

    Institute of Scientific and Technical Information of China (English)

    Zheng Xiucheng; Han Dongzhan; Wang Shuping; Zhang Shoumin; Wang Shurong; Huang Weiping; Wu Shihua

    2005-01-01

    CeO2 was synthesized via sol-gel process and used as supporter to prepare CuO/CeO2, Cu/CeO2 catalysts by impregnation method. The catalytic properties and characterization of CeO2, CuO/CeO2 and Cu/CeO2 catalysts were examined by means of a microreactor-GC system, HRTEM, XRD, TPR and XPS techniques. The results show that CuO has not catalytic activity and the activity of CeO2 is quite low for CO oxidation. However, the catalytic activity of CuO/CeO2 and Cu/CeO2 catalysts increases significantly. Furthermore, the activity of CuO/CeO2 is higher than that of Cu/CeO2 catalysts.

  12. Enhanced CO oxidation activity of CuO/CeO2 catalyst prepared by surfactant-assisted impregnation method

    Institute of Scientific and Technical Information of China (English)

    孙帅帅; 毛东森; 俞俊

    2015-01-01

    A modified CuO/CeO2 catalyst was prepared by surfactant-assisted impregnation method and showed better catalytic activity for low temperature CO oxidation than that from conventional impregnation method. The physicochemical properties of different CuO/CeO2 catalysts were characterized by thermogravimetric and differential scanning calorimetric measurements (TG-DSC), X-ray diffraction (XRD), N2 adsorption-desorption, Raman spectroscopy, H2 temperature-programmed reduction (H2-TPR), tem-perature-programmed desorption of O2 (O2-TPD), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The re-sults suggested that the addition of hexadecyl trimethyl ammonium bromide (CTAB) into the impregnation solution could improve the dispersion of CuO species, which could facilitate Cu2+ incorporating into CeO2 lattice and strengthened the synergistic effects between CuO and CeO2,making the lattice oxygen more active, and eventually resulting in enhanced activity for CO oxidation.

  13. Structural and chemical characteristics of atomically smooth GaN surfaces prepared by abrasive-free polishing with Pt catalyst

    Science.gov (United States)

    Murata, Junji; Sadakuni, Shun; Okamoto, Takeshi; Hattori, Azusa N.; Yagi, Keita; Sano, Yasuhisa; Arima, Kenta; Yamauchi, Kazuto

    2012-06-01

    This paper reports the structural and chemical characteristics of atomically flat gallium nitride (GaN) surfaces prepared by abrasive-free polishing with platinum (Pt) catalyst. Atomic force microscopy revealed regularly alternating wide and narrow terraces with a step height equivalent to that of a single bilayer on the flattened GaN surfaces, which originate from the differences in etching rate of two neighboring terraces. The material removal characteristics of the method for GaN surfaces were investigated in detail. We confirmed that an atomically smooth GaN surface with an extremely small number of surface defects, including pits and scratches, can be achieved, regardless of the growth method, surface polarity, and doping concentration. X-ray photoelectron spectroscopy showed that the flattening method produces clean GaN surfaces with only trace impurities such as Ga oxide and metallic Ga. Contamination with the Pt catalyst was also evaluated using total-reflection X-ray fluorescence analysis. A wet cleaning method with aqua regia is proposed, which markedly eliminates this Pt contamination without affecting the surface morphology.

  14. Structure of alumina supported vanadia catalysts for oxidative dehydrogenation of propane prepared by flame spray pyrolysis

    DEFF Research Database (Denmark)

    Høj, Martin; Jensen, Anker Degn; Grunwaldt, Jan-Dierk

    2013-01-01

    .%. The catalysts were subsequently characterized by BET surface area, X-ray diffraction (XRD), Raman, UV–vis diffuse reflectance and X-ray absorption spectroscopy (XAS) as well as measurement of the catalytic performance. The catalysts had specific surface areas from 143 to 169 m2/g corresponding to average.......1 VOx/nm2), a mixture of vanadia oligomers and monomers at 5wt.% V (3.6 VOx/nm2) and mainly oligomers at 7.5 and 10wt.% V (6.0 and 8.4 VOx/nm2). Diffuse reflectance UV–vis and extended X-ray absorption fine structure (EXAFS) spectroscopy measurements supported the results of Raman spectroscopy. In situ...... particles diameters from 9.0 to 10.9nm and apparent vanadia surface densities from 1.4 to 8.4 VOx/nm2. The only crystalline phase detected by XRD was γ-Al2O3, except at 10wt.% vanadium where traces of crystalline vanadia were observed. Raman spectroscopy showed vanadia monomers at 2 and 3wt.% V (1.4 and 2...

  15. "Hairy" Poly(3-hexylthiophene) Particles Prepared via Surface-Initiated Kumada Catalyst-Transfer Polycondensation

    DEFF Research Database (Denmark)

    Senkovskyy, Volodymyr; Tkachov, Roman; Beryozkina, Tetyana

    2009-01-01

    Herein, we present a new paradigm in the engineering of nanostructured hybrids between conjugated polymer and inorganic materials via a chain-growth surface-initiated Kumada catalyst-transfer polycondensation (SI-KCTP) from particles. Poly(3-hexylthiophene), P3HT, a benchmark material for organic...... this to strong interchain interactions within densely grafted P3HT chains, which can be tuned by changing the surface curvature (or size) of the supporting particle. The hairy P3HT nanoparticles were successfully applied in bulk heterojunction solar cells....... electronics, was selectively grown by SI-KCTP from (nano)particles bearing surface-immobilized Ni catalysts supported by bidentate phosphorus ligands, that resulted in hairy (nano)particles with end-tethered P3HT chains. Densely grafted P3HT chains exhibit strongly altered optical properties compared...... to the untethered counterparts (red shift and vibronic fine structure in absorption and fluorescence spectra), as a result of efficient planarization and chain-aggregation. These effects are observed in solvents that are normally recognized as good solvents for P3HT (e.g., tetrahydrofurane). We attribute...

  16. Preparation and Characterization of Malaysian Dolomites as a Tar Cracking Catalyst in Biomass Gasification Process

    Directory of Open Access Journals (Sweden)

    M. A. A. Mohammed

    2013-01-01

    Full Text Available Three types of local Malaysian dolomites were characterized to investigate their suitability for use as tar-cracking catalysts in the biomass gasification process. The dolomites were calcined to examine the effect of the calcination process on dolomite’s catalytic activity and properties. The modifications undergone by dolomites consequent to thermal treatment were investigated using various analytical methods. Thermogravimetric and differential thermal analyses indicated that the dolomites underwent two stages of decomposition during the calcination process. The X-ray diffraction and Fourier-transform infrared spectra analyses showed that thermal treatment of dolomite played a significant role in the disappearance of the CaMg(CO32 phase, producing the MgO-CaO form of dolomite. The scanning electron microscopy microphotographs of dolomite indicated that the morphological properties were profoundly affected by the calcination process, which led to the formation of a highly porous surface with small spherical particles. In addition, the calcination of dolomite led to the elimination of carbon dioxide and increases in the values of the specific surface area and average pore diameter, as indicated by surface area analysis. The results showed that calcined Malaysian dolomites have great potential to be applied as tar-cracking catalysts in the biomass gasification process based on their favorable physical properties.

  17. Ziegler-Natta catalysts for the preparation of polypropylene clay nanocomposites from magnesium ethoxide;Catalisadores Ziegler-Natta para preparacao de nanocompositos de polipropileno/argila partindo-se de etoxido de magnesio

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Maria de Fatima V.; Silva, Micheli G. da; Ferreira, Ana Luiza R., E-mail: fmarques@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Profa. Eloisa Mano; Ramis, Luciana B. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In the present work, the process for the preparation of Ziegler-Natta catalysts based on MgCl{sub 2}/TiCl{sub 4} was evaluated on the synthesis of isotactic polypropylene. The catalysts were produced by the chemical activation process aiming the morphology control, in order to obtain catalyst particles with spherical form. The synthesis of the catalytic support was accomplished from magnesium ethoxide at different preparation conditions. Commercial clays were also added in the preparation of ZN catalysts, which were employed in propylene polymerization. The purpose was to synthesizing polypropylene nanocomposites by in situ polymerization technique. The results indicated that the developed methods of catalyst preparation were effective, since they have shown high activities and they produced PP with high melting temperatures. It was possible to verify by XRD that the catalytic components were inserted in the clays galleries and the polymers obtained by means of those catalysts are possibly exfoliated nanocomposites. (author)

  18. High pressure organic colloid method for the preparation of high performance carbon nanotube-supported Pt and PtRu catalysts for fuel cell applications

    Institute of Scientific and Technical Information of China (English)

    WANG; KateNing; Viola; BIRSS

    2010-01-01

    Highly dispersed,high performance Pt and PtRu catalysts,supported on multiwalled carbon nanotubes(CNTs),were prepared by a high pressure organic colloid method.The particle sizes of the active components were as small as 1.2 nm for Pt and 1.1 nm for PtRu,and the active Pt surface areas were 295 and 395 m2/g,respectively.The catalysts showed very high activities toward the anodic oxidation of methanol,evaluated by cyclic voltammetry,being up to 4 times higher than that of commercial Johnson Matthey Hispec 2000 Pt/XC-72R and 5 times better than Hispec 5000 PtRu/XC-72R catalysts.In a full air/hydrogen fuel cell,a membrane-electrode assembly prepared using our Pt/CNT and PtRu/CNT catalysts showed 50% and 100% higher performances than those prepared with commercial Johnson Matthey Pt/XC-72R and PtRu/XC-72R catalysts for the same Pt loading and operating conditions.

  19. Effects of preparation method on the performance of Ni/Al(2)O(3) catalysts for hydrogen production by bio-oil steam reforming.

    Science.gov (United States)

    Li, Xinbao; Wang, Shurong; Cai, Qinjie; Zhu, Lingjun; Yin, Qianqian; Luo, Zhongyang

    2012-09-01

    Steam reforming of bio-oil derived from the fast pyrolysis of biomass is an economic and renewable process for hydrogen production. The main objective of the present work has been to investigate the effects of the preparation method of Ni/Al(2)O(3) catalysts on their performance in hydrogen production by bio-oil steam reforming. The Ni/Al(2)O(3) catalysts were prepared by impregnation, co-precipitation, and sol-gel methods. XRD, XPS, H(2)-TPR, SEM, TEM, TG, and N(2) physisorption measurements were performed to characterize the texture and structure of the catalysts obtained after calcination and after their subsequent use. Ethanol and bio-oil model compound were selected for steam reforming to evaluate the catalyst performance. The catalyst prepared by the co-precipitation method was found to display better performance than the other two. Under the optimized reaction conditions, an ethanol conversion of 99% and a H(2) yield of 88% were obtained.

  20. Catalyst and process development for hydrogen preparation from future fuel cell feedstocks. Quarterly report, April 1-June 30, 1980. [Pt/Pd

    Energy Technology Data Exchange (ETDEWEB)

    Yarrington, R M; Feins, I R; Hwang, H S

    1980-07-01

    Phase II of the contract, which involved catalyst preparation and evaluation, was nearly completed this quarter. Phase III, which calls for the design and construction of a fuel processor, was started. During the quarter, four types of tests were run on the small scale catalyst screening unit. The operating line for coke-free operations was found to be approximately between 0.41 to 0.44 O/sub 2//C level. Screening at lower O/sub 2//C levels led to problems with plugging. In other tests, increased severity for screening steam reforming catalysts was obtained by doubling the space velocity. Another series of tests were run to determine the gas composition from the catalytic partial oxidation (CPO) section and to evaluate two CPO catalysts. In the other series of tests, catalysts were aged for about 20 hours using a propane, steam, and air mixture before testing with No. 2 oil for another five hours. This latter test has been used to study Pt/Rh catalysts made with various supports. Differences were readily determined for Pt/Rh supported on alpha alumina and Pt/Rh supported on stabilized alumina. This test method will find continued use in evaluating metal-support interactions. Several samples must be evaluated by this method before aging runs are made in the larger unit. After leaching alumina from a used Pt/Rh catalyst, the x-ray diffraction pattern showed the presence of a Pt-Rh alloy in the metal residue. Experiments were run to show that the alloy was formed in the reactor during testing and not during catalyst preparation. A larger version of the ATR reactor has been designed and major components are on order. Completion of the construction phase is scheduled for the next quarter.

  1. Kinetic evaluation of highly active supported gold catalysts prepared from monolayer-protected clusters: an experimental Michaelis-Menten approach for determining the oxygen binding constant during CO oxidation catalysis.

    Science.gov (United States)

    Long, Cormac G; Gilbertson, John D; Vijayaraghavan, Ganesh; Stevenson, Keith J; Pursell, Christopher J; Chandler, Bert D

    2008-08-06

    Thiol monolayer-protected Au clusters (MPCs) were prepared using dendrimer templates, deposited onto a high-surface-area titania, and then the thiol stabilizers were removed under H2/N2. The resulting Au catalysts were characterized with transmission electron microscopy, X-ray photoelectron spectroscopy, and infrared spectroscopy of adsorbed CO. The Au catalysts prepared via this route displayed minimal particle agglomeration during the deposition and activation steps. Structural data obtained from the physical characterization of the Au catalysts were comparable to features exhibited from a traditionally prepared standard Au catalyst obtained from the World Gold Council (WGC). A differential kinetic study of CO oxidation catalysis by the MPC-prepared Au and the standard WGC catalyst showed that these two catalyst systems have essentially the same reaction order and Arrhenius apparent activation energies (28 kJ/mol). However, the MPC-prepared Au catalyst shows 50% greater activity for CO oxidation. Using a Michaelis-Menten approach, the oxygen binding constants for the two catalyst systems were determined and found to be essentially the same within experimental error. To our knowledge, this kinetic evaluation is the first experimental determination of oxygen binding by supported Au nanoparticle catalysts under working conditions. The values for the oxygen binding equilibrium constant obtained from the Michaelis-Menten treatment (ca. 29-39) are consistent with ultra-high-vacuum measurements on model catalyst systems and support density functional theory calculations for oxygen binding at corner or edge atoms on Au nanoparticles and clusters.

  2. Preparation, characterization and photocatalytic behavior of WO3-TiO2/Nb2O5 catalysts

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    TiO2/Nb2O5 photocatalyst loaded with WO3 (WO3-TiO2/Nb2O5) was prepared by a modified hydrolysis process, and characterized by X-ray diffractometry, transmission electron microscopy, Raman spectra and UV-Vis diffuse refraction spectroscopy.The photocatalytic activity of WO3-TiO2/Nb2O5 was investigated by employing splitting of water for O2 evolution. The results indicate that WO3 loading can pronouncedly improve the photocatalytic activity of TiO2/Nb2O5 by using Fe3+ as an electron acceptor under UV irradiation. The optimum molar fraction of the loaded WO3 is 2%, and the largest speed of O2 evolution for 2%WO3-TiO2/Nb2O5 catalyst is 151.8 μmol/(L·h).

  3. Preparation and characterization of highly active nanosized strontium-doped lanthanum cobaltate catalysts with high surface areas

    Institute of Scientific and Technical Information of China (English)

    NIU Jianrong; LIU Wei; DAI Hongxing; HE Hong; ZI Xuehong; LI Peiheng

    2006-01-01

    La1-xSrxCoO3-δ (x=0, 0.4) nanoparticles have been prepared using the citric acid complexing-hydrothermal synthesis coupled method and citric acid complexing method. The physico-chemical properties of these materials were characterized by means of X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), element analysis (EDX), X-ray photoelectron spectroscopic (XPS), oxygen temperature-programmed desorption (O2-TPD), hydrogen temperature-programmed reduction (H2-TPR) as well as surface area measurements and oxidation state titration. Their catalytic performance was examined for the total oxidation of ethylacetate (EA). It is found that the La1-xSrxCoO3-δ (x=0, 0.4) catalysts were single-phase and rhombohedrally-structured perovskites and their surface areas ranged from 16 to 26 m2/g. The Sr-doped sample derived from the coupled procedure was uniformly distributed nanoparticles with a short rod-shaped morphology. The doping of Sr (i) enhanced the concentrations of Co3+ and oxygen vacancies, (ii) increased the amount of oxygen adsorbed on the surface at low temperatures, (iii) promoted the mobility of lattice oxygen, and (iv) improved the properties of redox. The La0.6Sr0.4CoO2.78 catalyst prepared by the citric acid complexing-hydrothermal synthesis coupled strategy performed the best in the oxidation of EA, furthermore no partially oxidized products were formed. Based on the above results, we conclude that in addition to the surface area, the catalytic activity of the perovskite-type oxide nanoparticles was associated with the structural defect (oxygen vacancy)concentration and redox ability.

  4. Dry reforming of methane on Ni-Mg-Al nano-spheroid oxide catalysts prepared by the sol-gel method from hydrotalcite-like precursors

    Science.gov (United States)

    González, Albert R.; Asencios, Yvan J. O.; Assaf, Elisabete M.; Assaf, José M.

    2013-09-01

    Nanocapsular hydrotalcites (layered double hydroxides - LDHs) were synthesized by the sol-gel method and used as precursors of nano-structured mixed oxides containing various nickel loads (4, 15 and 19 wt%). The best conditions for the preparation of LDHs were analyzed and the structures of the resulting mixed oxides were studied. The optimal nickel load and calcining conditions were optimized. Finally, the resulting catalysts were tested in the dry reforming of methane for 8 h at 800 °C under atmospheric pressure. These materials showed high activity and stability, and the coke deposits were minimal on the catalyst prepared under optimal conditions (19 wt% nickel load and thermal treatment at 650 °C). The best catalyst formed amorphous carbon, which seems not to be prejudicial to the reaction.

  5. Cu-Co bi-metal catalyst prepared by perovskite CuO/LaCoO3 used for higher alcohol synthesis from syngas

    Institute of Scientific and Technical Information of China (English)

    Yuzhen Fang; Yuan Liu; Wei Deng; Junhai Liu

    2014-01-01

    Cu-Co bi-metal catalysts derived from CuO/LaCoO3 perovskite structure were prepared by one-step citrate complexing method, and the structure evolution reaction from CuO/LaCoO3 to Cu-Co2C/La2O2CO3 under H2 pretreatment was investigated by techniques of XRD, TPR and TEM. The results suggest that a much higher dispersion of copper significantly enhanced the reduction of cobalt, and a stronger interaction between copper and cobalt ions in LaCoO3 particles led to the formation of bi-metallic Cu-Co particles in the reduced catalysts and the enrichment of Co on the surface of bimetallic particles. The prepared catalysts were highly active and selective for the alcohol synthesis from syngas due to the presence of copper-modified Co2 C species.

  6. High performance CuO-CeO_2 catalysts for selective oxidation of CO in excess hydrogen: Effect of hydrothermal preparation conditions

    Institute of Scientific and Technical Information of China (English)

    Pengfei Zhu; Jing Li; Qinqin Huang; Siming Yan; Mei Liu; Renxian Zhou

    2009-01-01

    High performance CuO-CeO_2 catalysts for selective oxidation of CO in excess hydrogen were prepared by a hydrothermal method under different preparation conditions and evaluated for catalytic activities and selectivities. By changing the nCTAB/nCe ratio and hydrothermal aging time,the catalytic activity of the CuO-CeO_2 catalysts increased and the operating temperature window,in which the CO conversion was higher than 99%,was widened. XRD results showed no peaks of CuOx species and Cu-Ce-O solid solution were observed. On the other hand,Cu+ species in the CuO-CeO_2 catalysts,which was associated with a strong interaction between copper oxide clusters and cerium oxide and could be favorable for improving the selective oxidation performance of CO in excess H2,were detected by H2-TPR and XPS techniques.

  7. Influence of Si/Al Ratio on Catalytic Performance of (Co)Mo/Saponite Catalysts

    OpenAIRE

    Koningsberger, D.C.; Leliveld, R.G.; Ros, T.G.; van Dillen, A.J.; Geus, John W.

    1999-01-01

    The influence of the Si/Al ratio of the support of (Co)Mo/saponite catalysts on the performance in the hydrodesulfurisation of thiophene and hydrocracking of n-decane has been studied. The initial thiophene HDS activity of the sulfided Co catalysts increased with increasing support acidity, while with the CoMo catalysts the opposite effect was observed. The large drop in activity at lower Si/Al ratios is ascribed to the occurrence of two separate cobalt and molybdenum sulfide phases instead o...

  8. Preparation and Characterization of Carbon Nanotubes-Coated Cordierite for Catalyst Supports

    Institute of Scientific and Technical Information of China (English)

    Jianmei Wang; Rong Wang; Xiujin Yu; Jianxin Lin; Feng Xie; Kemei Wei

    2006-01-01

    The carbon nanotubes-coated cordierite (CNTs-cordierite) was fabricated by pyrolysis of ethine on cordierite with iron catalyst, which was penetrated into the cordierite substrate by vacuum impregnation. The cordierite substrate, carbon naontubes, and CNTs-cordierite were characterized by SEM, TEM/HREM, BET, and TGA. The results show that the carbon nanotubes were distributed uniformly on the surface of cordierite. A significant increase in BET surface area and pore volume was observed, and a suitable pore-size distribution was obtained. On the CNTs-cordierite, carbon nanotubes penetrated into the cordierite substrate, which led to a remarkable stability of the CNTs against ultrasound maltreatment. Growth time is an important factor for thermostability and texture of the sample. The mass increased but the purity decreased with the growth time, which caused the exothermic peak shift to low temperature, and the corresponding full width half maximum (FWHM) of the peak in DTG increased.

  9. Single-Step, Solvent-Free, Catalyst-Free Preparation of Holey Carbon Allotropes

    Science.gov (United States)

    Lin, Yi (Inventor); Kim, Jae-Woo (Inventor); Connell, John W. (Inventor); Funk, Michael R. (Inventor); Campbell, Caroline J. (Inventor)

    2017-01-01

    Methods for forming holey carbon allotropes and graphene nanomeshes are provided by the various embodiments. The various embodiments may be applicable to a variety of carbon allotropes, such as graphene, graphene oxide, reduced graphene oxide, thermal exfoliated graphene, graphene nanoribbons, graphite, exfoliated graphite, expanded graphite, carbon nanotubes (e.g., single-walled carbon nanotubes, double-walled carbon nanotubes, few-walled carbon nanotubes, multi-walled carbon nanotubes, etc.), carbon nanofibers, carbon fibers, carbon black, amorphous carbon, fullerenes, etc. The methods may produce holey carbon allotropes without the use of solvents, catalysts, flammable gas, additional chemical agents, or electrolysis to produce the pores (e.g., holes, etc.) in the carbon allotropes. In an embodiment, a carbon allotrope may be heated at a working window temperature for a working period of time to create holes in the carbon allotrope.

  10. Operando study of iridium acetylacetonate decomposition on amorphous silica-alumina for bifunctional catalyst preparation.

    Science.gov (United States)

    Nassreddine, Salim; Bergeret, Gérard; Jouguet, Bernadette; Geantet, Christophe; Piccolo, Laurent

    2010-07-28

    The decomposition of iridium acetylacetonate Ir(acac)(3) impregnated on amorphous silica-alumina (ASA) has been investigated by combined thermogravimetry-differential thermal analysis-mass spectrometry (TG-DTA-MS) and by in situ X-ray diffraction (XRD). The resulting Ir/ASA hydrotreating catalysts have also been characterized by transmission electron microscopy (TEM). The effects of heating treatments under oxidative, reductive or inert gas flows are compared with each other and with similar experiments on ASA-supported acetylacetone (acacH). It is shown that Ir(acac)(3) undergoes exothermic combustion during calcination in air, leading to agglomerated IrO(2) particles. Conversely, direct reduction involves hydrogenolysis of the acac followed by hydrogenation of the ligand residues to alkanes and water. These two processes are catalyzed by Ir clusters, the gradual growth of which is followed in situ by XRD. The resulting nanoparticles are highly and homogeneously dispersed.

  11. RANDOM COPOLYMER OF PROPYLENE OXIDE AND ETHYLENE OXIDE PREPARED BY DOUBLE METAL CYANIDE COMPLEX CATALYST

    Institute of Scientific and Technical Information of China (English)

    Yi-jun Huang; Guo-rong Qi; Guan-xi Chen

    2002-01-01

    Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by 13C-NMR and IR spectra. 1H-NMR analysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecular weight copolymers with various EO content were obtained and their values of molecular weight distribution (MWD) fell in the range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio ofEO + PO to initiator moles used. The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.

  12. Highly selective hydrogenation of CO2 to methanol over CuO-ZnO-ZrO2 catalysts prepared by a surfactant-assisted co-precipitation method

    Science.gov (United States)

    Li, Li; Mao, Dongsen; Yu, Jun; Guo, Xiaoming

    2015-04-01

    A series of CuO-ZnO-ZrO2 catalysts are synthesized by a surfactant-assisted co-precipitation method and tested for the synthesis of methanol from CO2 hydrogenation. The effects of calcination temperature on the physicochemical properties of as-prepared catalysts are investigated extensively by TG-DSC, N2 adsorption/desorption, XRD, N2O chemisorption, SEM/TEM, EDX, XPS, TPR, H2-TPD and CO2-TPD techniques. The results show that the size of copper particles increases with the increase in calcination temperature, leading to the decrease in turnover frequency (TOF) for methanol formation. Moreover, compared with the counterparts prepared by the conventional co-precipitation method, the CuO-ZnO-ZrO2 catalysts prepared by this novel method show significantly high methanol selectivity. The superior property of the prepared CuO-ZnO-ZrO2 catalyst can be attributed to the formation of more amounts of Cu-ZnOx and/or Cu-ZrOx species resulted from the homogeneous element distribution, intimate interface contact of Cu species with ZnO and/or ZrO2, and to porous structure with larger pore size.

  13. Mechanism of Alkene, Alkane, and Alcohol Oxidation with H2O2 by an in Situ Prepared Mn-II/Pyridine-2-carboxylic Acid Catalyst

    NARCIS (Netherlands)

    Saisaha, Pattama; Dong, Jia Jia; Meinds, Tim G.; de Boer, Johannes W.; Hage, Ronald; Mecozzi, Francesco; Kasper, Johann B.; Browne, Wesley R.

    2016-01-01

    The oxidation of alkenes, alkanes, and alcohols with H2O2 is catalyzed efficiently using an in situ prepared catalyst comprised of a MnII salt and pyridine-2-carboxylic acid (PCA) together with a ketone in a wide range of solvents. The mechanism by which these reactions proceed is elucidated, with a

  14. Synthesis and characterization of alumina-supported vanadium oxide catalysts prepared by the molecular designed dispersion of VO(acac)2 complexes

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Baltes, M.; Voort, P. van der; Ramachandra Rao, R.; Catana, Gabriela; Schoonheydt, R.A.; Vansant, E.F.

    2000-01-01

    Alumina-supported vanadium oxide catalysts have been prepared by the molecular designed dispersion method, using the vanadyl acetylacetonate complex (VO(acac)2). The complex has been adsorbed on the support from solution, followed by thermal conversion into the corresponding supported vanadium oxide

  15. Preparation of highly dispersed W/Al2O3 hydrodesulfurization catalysts via a microwave hydrothermal method: Effect of oxalic acid

    Directory of Open Access Journals (Sweden)

    Hao Wang

    2016-01-01

    Full Text Available A novel microwave hydrothermal method was developed to prepare highly dispersed W/Al2O3 catalysts, in which WO3 was deposited on alumina via precipitation between tungstate and nitric acid under microwave hydrothermal environment and oxalic acid was used as an additive. Moreover, the role of oxalic acid was investigated by varying its amount and the addition method. It is found that the catalysts show higher WO3 dispersion and weaker W–Al interaction than that prepared by the conventional impregnation method. The hydrothermal period can be extremely reduced to a few minutes, and highly dispersed WO3 can be achieved even without oxalic acid. When oxalic acid was added after the formation of H2WO4, it mainly acts as a modifier for reacting with the hydroxyl groups on alumina and has little effect on WO3 dispersion. When oxalic acid was divided into two parts, one for pretreating alumina and the remains for preventing the aggregation of H2WO4, it may effectively act as both dispersant and modifier, leading to further increased WO3 dispersion and weakened W–Al interaction. The catalysts prepared by the microwave hydrothermal method show superior dibenzothiophene hydrodesulfurization activity. This method provides rapidity, convenience and cost effectiveness for preparing active hydrotreating catalysts.

  16. Fundamentals of Melt infiltration for the Preparation of Supported Metal Catalysts.The Case of Co/SiO2 Fischer-Tropsch Synthesis

    NARCIS (Netherlands)

    Eggenhuisen, T.M.; den Breejen, J.P.; Verdoes, D.; de Jongh, P.E.; de Jong, K.P.

    2013-01-01

    We explored melt infiltration of mesoporous silica supports to prepare supported metal catalysts with high loadings and controllable particle sizes. Melting of Co(NO3)2 ·6H2O in the presence of silica supports was studied in situ with differential scanning calorimetry. The melting point depression o

  17. Mono- and bimetallic Rh and Pt NSR-catalysts prepared by controlled deposition of noble metals on support or storage component.

    Science.gov (United States)

    Büchel, Robert; Pratsinis, Sotiris E; Baiker, Alfons

    2012-02-22

    Mono- and bimetallic Rh and Pt based NOx storage-reduction (NSR) catalysts, where the noble metals were deposited on the Al2O3 support or BaCO3 storage component, have been prepared using a twin flame spray pyrolysis setup. The catalysts were characterized by nitrogen adsorption, CO chemisorption combined with diffuse reflectance infrared Fourier transform spectroscopy, X-ray diffraction, and scanning transmission electron microscopy combined with energy dispersive X-ray spectroscopy. The NSR performance of the catalysts was investigated by fuel lean/rich cycling in the absence and presence of SO2 (25 ppm) as well as after H2 desulfation at 750 °C. The performance increased when Rh was located on BaCO3 enabling good catalyst regeneration during the fuel rich phase. Best performance was observed for bimetallic catalysts where the noble metals were separated, with Pt on Al2O3 and Rh on BaCO3. The Rh-containing catalysts generally showed much higher tolerance to SO2 during fuel rich conditions and lost only little activity during thermal aging at 750 °C.

  18. NiO-Ce0.5Zr0.5O2 catalysts prepared by citric acid method for steam reforming of ethanol

    Institute of Scientific and Technical Information of China (English)

    YE Jilei; WANG Yang; LIU Yuan

    2008-01-01

    NiO-Ce0.5Zr0.5O2catalysts were prepared by citrate method and used for hydrogen production from steam reforming of ethanol (SRE). The effect of nickel content and space velocity on the catalytic performance was investigated. The prepared catalysts were character-ized with XRD and thermal analysis techniques. 20%NiO-Ce0.5Zr0.5O2 catalyst was very active and selective for hydrogen production via SRE, in which ethanol conversion of 100% could be obtained with feed component of 20% (H2O+EtOH) and 80% N2, water/ethanol of 3/1 in molar ratio at 350 ℃. Also, the catalyst showed good stability for anti-sintering and carbon-resistance. The XRD illuminated that both NiO and Ce0.5Zr0.5O2 crystal sizes were very small in NiO-Ce0.5Zr0.5O2 catalyst, and Ce0.5Zr0.5O2 solid solution was formed.

  19. Enhancement in Activity of a Vanadium Catalyst for the Oxidation of Sulfur Dioxide by Radio Frequency Plasma During the Preparation Process

    Institute of Scientific and Technical Information of China (English)

    Zhenxing Chen; Honggui Li; Lingsen Wang

    2003-01-01

    Radio frequency plasma was used to prepare a vanadium catalyst. The results showed that activating time of the catalyst could be shortened quickly and the catalytic activity was improved to some extent with the use of plasma. Catalyst Ls-9 was prepared under an optimal condition of 40 W discharge power, 10 min discharge time and 8 Pa gas pressure. The catalytic activity was up to 54.7% at 410 ℃,which was 2.2% higher than that of the Ls-8 catalyst. Only 10 min was needed to activate the catalyst with plasma, which was 1/9 of the traditional calcination time. For Ls-9, both the endothermic as well as the exothermic peaks detected by differential thermal analysis shifted to higher temperatures obviously,indicating that its crystal phase could melt easily. There existed an apparent endothermic peak at 283 ℃. SEM photographs showed a uniform size distribution. It is inferred that the quadrivalent vanadium compound may exist mainly in the form of VOSO4.

  20. Preparation of Highly Active Pt-K/γ-AI203 Catalyst for 0-Phenylphenol Synthesis from 0-Cyclohexenyl-cyclohexanone Dehydrogenation

    Institute of Scientific and Technical Information of China (English)

    DING Jie-lian; LIN Ling; XU Jian-dong; ZENG Chong-yu

    2008-01-01

    0.5%Pt-K/y-Al2O3 catalysts for the synthesis of 0-phenylphenol(OPP) from 0-cyclohexenyl-cyciohexanone (dimer) dehydrogenation were prepared by means of a two subsequent impregnation method.The effects of catalyst preparation parameters,such as K promoters,calcination,and reduction conditions,were investigated.The results showed that the addition of K2SO4 to Pt/y-Al2O3 catalyst notably promoted the selectivity of OPP,and its optimum content was found to be 6% in mass fraction.The higher activity was obtained when Pt/y-Al2O3 catalyst was calcined in nitrogen atmosphere at 400-500℃ and then reduced at the same temperature for 3 h in hydrogen atmosphere.The conversion of the dimer and the selectivity of OPP were always above 99% and 90%,respectively,over 0.5%Pt-6% K2SO4/γ-Al2O3 catalyst during the pilot scale test of 8000 h.

  1. Preparation of TiO2-MoO3 nano-composite photo-catalyst by supercritical fluid dry method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-chang; LI Qing; CAO Wei-liang

    2005-01-01

    A series of TiO2-MoO3 nano-composite photocatalysts were prepared by supercritical fluid dry method (SCFD) and an XRD, TEM and UV-Vis. Methyl orange was used as model compound for the evaluation of their catalytic activities. The results indicated that the photo-catalyst prepared by SCFD had the advantages of small size( 12.84 nm), narrow distribution and good dispersivity. The presence of small amount of Mo in composite catalyst gives rise to the red shift of its absorbance wavelength, decrease of its energy gap and increase of the utility of visible light. Furthermore, higher surface acidity of the photo-catalyst was obtained as the result of the addition of MoO3. Compared with pure TiO2, the catalytic activity of the TiO2-MoO3 nano-composite photo-catalyst was improved significantly. As the doping concentration of the composite catalysts was controlled at 0.6% (molar percentage), 100% degradation of methyl orange was achieved with in 1.2 h irradiation time.

  2. Effect of precipitants on Ni-CeO2 catalysts prepared by a co-precipitation method for the reverse water-gas shift reaction

    Institute of Scientific and Technical Information of China (English)

    王路辉; 刘辉; 刘源; 陈英; 杨淑清

    2013-01-01

    A series of Ni-CeO2 catalysts were prepared by co-precipitation method with Na2CO3, NaOH, and mixed precipitant (Na2CO3:NaOH;1:1 ratio) as precipitant, respectively. The effect of the precipitants on the catalytic performance, physical and chemical properties of Ni-CeO2 catalysts was investigated with the aid of X-ray diffraction (XRD), Brumauer-Emmett-Teller method (BET), Fou-rier-transform infrared spectroscopy (FT-IR), thermogravimetry (TG), and H2-TPR characterizations. The Ni-CeO2 catalysts were exam-ined with respect to their catalytic performance for the reverse water-gas shift reaction, and their catalytic activities were ranked as:Ni-CeO2-CP (Na2CO3:NaOH=1:1)>Ni-CeO2-CP(Na2CO3)>Ni-CeO2-CP(NaOH). Correlating to the characteristic results, it was found that the catalyst prepared by co-precipitation with mixed precipitant (Na2CO3:NaOH; 1:1 ratio) as precipitant had the most amount of oxygen vacancies accompanied with highly dispersed Ni particles, which made the corresponding Ni-CeO2-CP(Na2CO3:NaOH=1:1) catalyst exhibit the highest catalytic activity. While the precipitant of Na2CO3 or NaOH resulted in less or no oxygen vacancies in Ni-CeO2 catalysts. As a result, Ni-CeO2-CP(Na2CO3) and Ni-CeO2-CP(NaOH) catalysts presented poor catalytic performance.

  3. Preparation and evaluation of advanced catalysts for phosphoric acid fuel cells

    Science.gov (United States)

    Stonehart, P.; Baris, J.; Hockmuth, J.; Pagliaro, P.

    1984-01-01

    The platinum electrocatalysts were characterized for their crystallite sizes and the degree of dispersion on the carbon supports. One application of these electrocatalysts was for anodic oxidation of hydrogen in hot phosphoric acid fuel cells, coupled with the influence of low concentrations of carbon monoxide in the fuel gas stream. In a similar way, these platinum on carbon electrocatalysts were evaluated for oxygen reduction in hot phosphoric acid. Binary noble metal alloys were prepared for anodic oxidation of hydrogen and noble metal-refractory metal mixtures were prepared for oxygen reduction. An exemplar alloy of platinum and palladium (50/50 atom %) was discovered for anodic oxidation of hydrogen in the presence of carbon monoxide, and patent disclosures were submitted. For the cathode, platinum-vanadium alloys were prepared showing improved performance over pure platinum. Preliminary experiments on electrocatalyst utilization in electrode structures showed low utilization of the noble metal when the electrocatalyst loading exceeded one weight percent on the carbon.

  4. Facile preparation of hierarchically porous carbon using diatomite as both template and catalyst and methylene blue adsorption of carbon products.

    Science.gov (United States)

    Liu, Dong; Yuan, Peng; Tan, Daoyong; Liu, Hongmei; Wang, Tong; Fan, Mingde; Zhu, Jianxi; He, Hongping

    2012-12-15

    Hierarchically porous carbons were prepared using a facile preparation method in which diatomite was utilized as both template and catalyst. The porous structures of the carbon products and their formation mechanisms were investigated. The macroporosity and microporosity of the diatomite-templated carbons were derived from replication of diatom shell and structure-reconfiguration of the carbon film, respectively. The macroporosity of carbons was strongly dependent on the original morphology of the diatomite template. The macroporous structure composed of carbon plates connected by the pillar- and tube-like macropores resulted from the replication of the central and edge pores of the diatom shells with disk-shaped morphology, respectively. And another macroporous carbon tubes were also replicated from canoe-shaped diatom shells. The acidity of diatomite dramatically affected the porosity of the carbons, more acid sites of diatomite template resulted in higher surface area and pore volume of the carbon products. The diatomite-templated carbons exhibited higher adsorption capacity for methylene blue than the commercial activated carbon (CAC), although the specific surface area was much smaller than that of CAC, due to the hierarchical porosity of diatomite-templated carbons. And the carbons were readily reclaimed and regenerated. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Preparation of a Modified PTFE Fibrous Photo-Fenton Catalyst and Its Optimization towards the Degradation of Organic Dye

    Directory of Open Access Journals (Sweden)

    Zhizhong Ding

    2012-01-01

    Full Text Available Polytetrafluoroethylene (PTFE fiber was grafted with acrylic acid to impart the carboxyl groups onto the fiber surface, which were used to coordinate with both transition metal ions Fe(III and Cu(II and a rare metal ion Ce(III to prepare the metal grafted PTFE fiber complexes as the novel heterogeneous Fenton catalysts for the degradation of the azo dye in water under visible irradiation. Some factors affecting the preparation process, such as nature and concentration of metal ions in the coordination solution, grafting degree of PTFE and reaction temperature were optimized with respect to the content and strength of metal fixation on the fiber and dye degradation efficiency. The results indicated that increasing metal ion concentrations in solution and grafting degree of PTFE fiber as well as higher coordination temperature led to a significant increase in metal content, especially Fe(III and Cu(II content of the complexes. Fe(III ions fixed on the fiber showed the better catalytic performance than Cu(II and Ce(III ions fixed when three different complexes with similar metal content being employed, respectively. Moreover, Increasing Fe content or incorporation of Cu(II ions could significantly improve the catalytic activity of the complexes.

  6. A way to inhibit SO[sub 2] poisoning of SCR catalysts by fine tuning of the composition and the preparation method of the support

    Energy Technology Data Exchange (ETDEWEB)

    Matralis, H.; Fiasse, S.; Bastians, Ph.; Ruwet, M.; Grange, P.; Delmon, B. (Unite de Catalyse et Chimie des Materiaux Divise, Louvain-la-Neuve (Belgium)); Castillo, R. (Monomeros Colombo Venezolanos (EMA), Las Flores Barranquilla (Colombia))

    1993-05-26

    Two series of mixed SiO[sub 2]-TiO[sub 2] and Al[sub 2]O[sub 3]-TiO[sub 2] supports were prepared by the following methods: precipitation from TiCl[sub 4] solution with aqueous ammonia, impregnation with titanium isopropoxide solution in isopropanol, and grafting by reaction of TiCl[sub 4] with the hydroxyl groups of the main carrier (SiO[sub 2] or Al[sub 2]O[sub 3]). The vanadia catalysts, resulting from the impregnation of these mixed supports with an aqueous solution of vanadium oxalate, were tested in the selective catalytic reduction-(SCR) of NO with NH[sub 3] in the presence of O[sub 2]. BET, XRD and XPS were used to characterise the samples. All these catalysts were less active than a standard TiO[sub 2]-V[sub 2]O[sub 5] catalyst when tested with a SO[sub 2]-free feed. However, in the presence of 4000 ppm SO[sub 2] in the feed they were more resistant and more active than the TiO[sub 2]-V[sub 2]O[sub 5] catalyst. Our results indicate that the dispersion of TiO[sub 2] on the main carrier is a key factor for preparing a performant SCR-catalyst. The grafting and impregnation methods for the Al[sub 2]O[sub 3]-TiO[sub 2] and the impregnation for the SiO[sub 2]-TiO[sub 2] supports were found to be the most effective preparation techniques for dispersing TiO[sub 2], and for giving the most performant and resistant, towards SO[sub 2] poisoning, catalysts.

  7. Effect of the Pd/MWCNTs anode catalysts preparation methods on their morphology and activity in a direct formic acid fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Lesiak, B., E-mail: blesiak-orlowska@ichf.edu.pl [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa (Poland); Mazurkiewicz, M.; Malolepszy, A. [Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645 Warszawa (Poland); Stobinski, L. [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa (Poland); Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645 Warszawa (Poland); Mierzwa, B.; Mikolajczuk-Zychora, A.; Juchniewicz, K.; Borodzinski, A. [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa (Poland); Zemek, J.; Jiricek, P. [Institute of Physics, Academy of Sciences of the Czech Republic, 162-53 Prague 6, Cukrovarnicka 10 (Czech Republic)

    2016-11-30

    Highlights: • Catalysts properties studied by XRD, STEM, XPS methods. • Differences in Pd particle size, content of Pd, functional groups, PdC{sub x.}. • Catalytic activity studied in a Direct Formic Acid Fuel Cell. • Highest activity–catalyst prepared using a strong reducing agent (NaBH{sub 4}). - Abstract: Impact of Pd/MWCNTs catalysts preparation method on the catalysts morphology and activity in a formic acid electrooxidation reaction was investigated. Three reduction methods of Pd precursor involving reduction in a high pressure microwave reactor (Pd1), reduction with NaBH{sub 4} (Pd2) and microwave-assisted polyol method (Pd3) were used in this paper. Crystallites size and morphology were studied using the scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), whereas elemental composition, Pd chemical state and functional groups content by the X-ray photoelectron spectroscopy (XPS). The prepared catalysts were tested in a direct formic acid fuel cell (DFAFC) as an anode material. The catalytic activity was correlated with a mean fraction of the total Pd atoms exposed at the surface (FE). The value of FE was calculated from the crystallites size distribution determined by the STEM measurements. Non-linear dependence of a current density versus FE, approaching the maximum at FE≈0.25 suggests that the catalytic process proceeded at Pd nanocrystallites faces, with inactive edges and corners. Pd2 catalyst exhibited highest activity due to its smallest Pd crystallites (3.2 nm), however the absence of Pd crystallites aggregation and low content of carbon in PdC{sub x} phase, i.e. x = 4 at.% may also affect the observed.

  8. Designing Photocatalysts for Hydrogen Evolution: Are Complex Preparation Strategies Necessary to Produce Active Catalysts?

    Science.gov (United States)

    Grewe, Tobias; Tüysüz, Harun

    2015-09-21

    A facile synthetic route for the preparation of highly active photocatalysts was developed. The protocol involves the preparation of a photocatalyst through the direct injection of metal alkoxide precursors into solutions in a photoreactor. As a proof of concept, a tantalum oxide based photocatalyst was chosen as a model system. Tantalum ethoxide [Ta(OEt)5 ] was injected rapidly into a photoreactor filled with a water/methanol mixture, and a TaOx (OH)y composite formed and was able to produce hydrogen under light illumination. Compared to commercial and mesostructured Ta2 O5 and NaTaO3 materials, TaOx (OH)y produced by direct injection shows superior hydrogen production activity. Notably, the samples prepared by direct injection are amorphous; however, their photocatalytic performance is much higher than those of their crystalline equivalents. If Ta(OEt)5 was dispersed in methanol before injection, an amorphous framework with higher surface area and larger pore volume was formed, and the hydrogen production rate increased further. The addition of a sodium precursor during the injection further boosted the photocatalytic activity. Furthermore, this concept has also been applied to a titanium-based photocatalyst, and a much better hydrogen production rate has been obtained in comparison with that of commercial TiO2 (P25-Degussa); therefore, the direct-injection synthesis is a flexible method that opens the door to the facile preparation of highly active nanostructured photocatalysts for hydrogen production.

  9. Simulation of Low-Temperature Coal Tar Hydrocracking in Supercritical Gasoline

    Institute of Scientific and Technical Information of China (English)

    Zhang Lei; Liu Zongkuan; Gu Zhaolin

    2013-01-01

    The aim of this paper was preliminary design of the process for low-temperature coal tar hydrocracking in supercritical gasoline based on Aspen Plus with the concept of energy self-sustainability. In order to ensure the correct-ness and accuracy of the simulation, we did the following tasks: selecting reasonable model compounds for low-tem-perature coal tar; describing the nature of products gasoline and diesel accurately; and conifrming the proper property study method for each block by means of experience and trial. The purpose of energy self-sustainability could be pos-sibly achieved, on one hand, by using hot stream to preheat cold stream and achieving temperature control of streams, and on the other hand, by utilizing gas (byproduct of the coal tar hydrocracking) combustion reaction to provide energy. Results showed that the whole process could provide a positive net power of about 609 kW·h for processing the low-temperature coal tar with a lfowrate of 2 268 kg/h. The total heat recovery amounted to 2 229 kW·h, among which 845 kW·h was obtained from the gas combustion reaction, and 1 116 kW·h was provided by the reactor’s outlet stream, with the rest furnished by hot streams of the products gasoline, diesel and residue. In addition, the process lfow sheet could achieve products separation well, and speciifcally the purity of product gasoline and diesel reached 97.2% and 100%, respectively.

  10. Design and Stereoselective Preparation of a New Class of Chiral Olefin Metathesis Catalysts and Application to Enantioselective Synthesis of Quebrachamine: Catalyst Development Inspired by Natural Product Synthesis

    Science.gov (United States)

    Sattely, Elizabeth S.; Meek, Simon J.; Malcolmson, Steven J.; Schrock, Richard R.; Hoveyda, Amir H.

    2010-01-01

    A total synthesis of the Aspidosperma alkaloid quebrachamine in racemic form is first described. A key catalytic ring-closing metathesis of an achiral triene is used to establish the all-carbon quaternary stereogenic center and the tetracyclic structure of the natural product; the catalytic transformation proceeds with reasonable efficiency through the use of existing achiral Ru or Mo catalysts. Ru- or Mo-based chiral olefin metathesis catalysts have proven to be inefficient and entirely nonselective in cases where the desired product is observed. In the present study, the synthesis route thus serves as a platform for the discovery of new olefin metathesis catalysts that allow for efficient completion of an enantioselective synthesis of quebrachamine. Accordingly, on the basis of mechanistic principles, stereogenic-at-Mo complexes bearing only monodentate ligands have been designed. The new catalysts provide significantly higher levels of activity than observed with the previously reported Ru- or Mo-based complexes. Enantiomerically enriched chiral alkylidenes are generated through diastereoselective reactions involving achiral Mo-based bispyrrolides and enantiomerically pure silyl-protected binaphthols. Such chiral catalysts initiate the key enantioselective ring-closing metathesis step in the total synthesis of quebrachamine efficiently (1 mol % loading, 22 °C, 1 h, >98% conversion, 84% yield) and with high selectivity (98:2 er, 96% ee). PMID:19113867

  11. Design of heterogeneous catalysts

    DEFF Research Database (Denmark)

    Frey, Anne Mette

    was inspired by a computational screening, suggesting that alloys such as Ni-Fe, Co-Ni, and Co-Fe should show superior activity to the industrially used nickel catalyst. Especially the Ni-Fe system was considered to be interesting, since such alloy catalysts should be both more active and cheaper than the Ni...... well, and the best catalyst prepared had a C5+ yield almost a factor of two higher than a standard air calcined Co catalyst. In the NH3-SCR reaction it is desirable to develop an active and stable catalyst for NOx removal in automotive applications, since the traditionally used vanadium-based catalyst...... pose an environmental risk. The focus was put on iron-containing zeolite catalysts, since these recently have shown great potential as catalysts for the process. A number of different zeolites were compared. BEA was found to be the most active, thus focus was put on this material. Different preparation...

  12. Preparation of ceria-zirconia by modified coprecipitation method and its supported Pd-only three-way catalyst.

    Science.gov (United States)

    Lan, Li; Chen, Shanhu; Cao, Yi; Zhao, Ming; Gong, Maochu; Chen, Yaoqiang

    2015-07-15

    A CeO2-ZrO2 compound with mixed phase composition (CZ4) was prepared by modified co-precipitation method, and for comparison, single-phase Ce(0.2)Zr(0.8)O2, Ce(0.5)Zr(0.5)O2 and Ce(0.8)Zr(0.2)O2 were synthesized via simultaneous co-precipitation method. The textural, structural and redox properties, together with the catalytic performance of the supported Pd-only three-way catalysts were investigated systematically. The results revealed that the generation of numerous interface sites in Pd/CZ4 due to its mixed phase composition (as confirmed by TEM observation) had a positive influence on modifying its structural, redox properties and thermal stability. The XRD and Raman results revealed that the highest structural stability was obtained by Pd/CZ4 with negligible lattice variation and slightest grain growth after aging treatment. The XPS analysis demonstrated that the compositional heterogeneity of Pd/CZ4 could facilitate the formation of Ce(3+), and was beneficial to preserve high dispersion of Pd as well as maintain Pd at a more oxidized state. The H2-TPR and oxygen storage capacity measurements indicated that Pd/CZ4 possessed highest reduction ability as well as largest oxygen storage capacity regardless of thermal aging treatment. And consequently Pd/CZ4 exhibited improved three-way catalytic activity compared with the catalysts supported on single-phase Ce(x)Zr(1-x)O2 both before and after thermal aging treatment.

  13. New eco-friendly animal bone meal catalysts for preparation of chalcones and aza-Michael adducts

    Directory of Open Access Journals (Sweden)

    Riadi Yassine

    2012-06-01

    Full Text Available Abstract Two efficient reactions were successfully carried out using Animal Bone Meal (ABM and potassium fluoride or sodium nitrate doped ABMs as new heterogeneous catalysts under very mild conditions. After preparation and characterization of the catalysts, we first report their use in a simple and convenient synthesis of various chalcones by Claisen–Schmidt condensation and then in an aza-Michael addition involving several synthesized chalcones with aromatic amines. All the reactions were carried out at room temperature in methanol; the chalcone synthesis was also achieved in water environment under microwave irradiation. Doping ABM enhances the rate and yield at each reaction. Catalytic activities are discussed and the ability to re-use the ABM is demonstrated. Results For Claisen–Schmidt the use of ABM alone, yields never exceeded 17%. In each entry, KF/ABM and NaNO3/ABM (79-97% gave higher yields than using ABM alone under thermic condition. Also the reaction proceeded under microwave irradiation in good yields (72-94% for KF/ABM and 81-97% for NaNO3/ABM and high purity. For aza-Michael addition the use of ABM doped with KF or NaNO3 increased the catalytic activity remarkably. The very high yields could be noted (84-95% for KF/ABM and 81-94% for NaNO3/ABM. Conclusion The present method is an efficient and selective procedure for the synthesis of chalcones an aza-Michael adducts. The ABM and doped ABMs are a new, inexpensive and attractive solid supports which can contribute to the development of catalytic processes and reduced environmental problems.

  14. Preparation and catalytic properties of ZrO2-Al2O3 composite oxide supported nickel catalysts for methane reforming with carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    HAO Zheng-ping; HU Chun; JIANG Zheng; G. Q. LU

    2004-01-01

    ZrO2-Al2O3 composite oxides and supported Ni catalysts were prepared , and characterized by N2adsorption/desorption, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy ( XPS ) techniques. Thecatalytic performance and carbon deposition was also investigated. This mesoporous composite oxide is shown to bea promising catalyst support. An increase in the catalytic activity and stability of methane and carbon dioxidereforming reaction was resulted from the zirconia addition, especially at 5wt% ZrO2 content. The Ni catalystsupported ZrO2-Al2O3 has a strong resistance to sintering and the carbon deposition in a relatively long-termreaction.

  15. Influence of excess sodium ions on the specific surface area formation in a NiO-Al2O3 catalyst prepared by different methods

    Directory of Open Access Journals (Sweden)

    Lazić M.M.

    2008-01-01

    Full Text Available The influence of sodium ions on the specific surface area of a NiO-Al2O3 catalyst in dependence of nickel loading (5, 10, and 20 wt% Ni, temperature of heat treatment (400, 700 and 1100oC and the method of sample preparation was investigated. Low temperature nitrogen adsorption (LTNA, X-ray diffraction (XRD and scanning electron microscopy (SEM were applied for sample characterization. Dramatic differences in the specific surface area were registered between non-rinsed and rinsed Al2O3 and NiO-Al2O3 samples. The lagged sodium ions promote sintering of non-rinsed catalyst samples.

  16. Preparation and characterization of Fe2O3-CeO2-TiO2/γ-Al2O3 catalyst for degradation dye wastewater

    Institute of Scientific and Technical Information of China (English)

    LIU Yan; SUN De-zhi; CHENG Lin; LI Yan-ping

    2006-01-01

    In order to develop a catalyst with high activity for catalytic wet oxidation (CWO) process at room temperature and atmospheric pressure, Fe2O3-CeO2-TiO2/γ-Al2O3 catalyst was prepared by consecutive impregnation method and the prepared parameters were optimized. The structure of the catalyst was characterized by BET, XRF, SEM and XPS technologies, and the actual wastewater was used to investigate the catalytic activity of Fe2O3-CeO2-TiO2/γ-Al2O3 in CWO process. The experimental results showed that the prepared catalyst exhibited good catalytic activity when the doping amount of Ti was 1.0 wt% (the weight ratio of Ti to carriers), and the middle product, CeO2-TiO2/γ-Al2O3, was calcined in 450℃ for 2 h. The CWO experiment for treating actual dye wastewater indicated that the COD, color and TOC of actual wastewater were decreased by 62.23%, 50.12% and 41.26% in 3 h,respectively, and the ratio of BOD5/COD was increased from 0.19 to 0.30.

  17. Preparation of Pt-Ru@ polypyrrole-MWNT catalysts by gamma-irradiation and chemical reduction and their adsorption capacity for CO.

    Science.gov (United States)

    Bae, Hyoung-Bong; Oh, Sang-Hyub; Woo, Jin-Chun; Choi, Seong-Ho

    2010-10-01

    With the objective to prepare electrocatalysts with high efficiency, the Pt-Ru@PPy-MWNT catalysts were prepared by different approaches. First, the polypyrrole (PPy) as anchoring materials was coated on the surface of multi walled carbon nanotubes (MWNT) by in situ polymerization. Subsequently, Pt-Ru nanoparticles were deposited onto PPy-MWNT composite by different methods like the reduction of metal ions by gamma-irradiation and chemical reduction using formaldehyde as reducing agent assisted with stirring of magnetic bar, and assisted with microwave irradiation, and assisted with ultrasonic irradiation, in order to prepare electrocatalyst for fuel cell. The catalytic efficiency of Pt-Ru@PPy-MWNT catalyst was examined for CO stripping.

  18. Comparison of Kinetic-based and Artificial Neural Network Modeling Methods for a Pilot Scale Vacuum Gas Oil Hydrocracking Reactor

    Directory of Open Access Journals (Sweden)

    Sepehr Sadighi

    2013-12-01

    Full Text Available An artificial neural network (ANN and kinetic-based models for a pilot scale vacuum gas oil (VGO hydrocracking plant are presented in this paper. Reported experimental data in the literature were used to develop, train, and check these models. The proposed models are capable of predicting the yield of all main hydrocracking products including dry gas, light naphtha, heavy naphtha, kerosene, diesel, and unconverted VGO (residue. Results showed that kinetic-based and artificial neural models have specific capabilities to predict yield of hydrocracking products. The former is able to accurately predict the yield of lighter products, i.e. light naphtha, heavy naphtha and kerosene. However, ANN model is capable of predicting yields of diesel and residue with higher precision. The comparison shows that the ANN model is superior to the kinetic-base models.  © 2013 BCREC UNDIP. All rights reservedReceived: 9th April 2013; Revised: 13rd August 2013; Accepted: 18th August 2013[How to Cite: Sadighi, S., Zahedi, G.R. (2013. Comparison of Kinetic-based and Artificial Neural Network Modeling Methods for a Pilot Scale Vacuum Gas Oil Hydrocracking Reactor. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (2: 125-136. (doi:10.9767/bcrec.8.2.4722.125-136][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.2.4722.125-136

  19. THE EFFECT OF THE ACID CATALYST ON THE PREPARATION OF MQ SILICONE RESINS

    Institute of Scientific and Technical Information of China (English)

    Wei Huang; Ying Huang; Yun-zhao Yu

    1999-01-01

    MQ silicone resins were prepared through hydrolytic condensation of ethyl polysilicate or tetraethoxysilane and hexamethyl disiloxane. The unit ratio of the MQ resins was determined by 29Si-NMR.The relationship of the unit ratio of the product resins with that in the feed was studied. When the reaction was catalyzed by aqueous hydrochloric acid, and the unit ratio of M to Q in the feed was more than 1, the unit ratio of the product was usually lower than that of the feed. The MQ silicon with an unit ratio of M/Q>2 could not be obtained. However, if the reaction was catalyzed by concentrated sulfuric acid and the reverse hydrolysis process was employed, MQ silicone resin with very high M/Q ratio was successfully prepared.

  20. Ni-M-O (M=Sn, Ti and W) catalysts prepared from dry mixing method for oxidative dehydrogenation of ethane

    KAUST Repository

    Zhu, Haibo

    2016-03-25

    A new generation of Ni-Sn-O, Ni-Ti-O, and Ni-W-O catalysts has been prepared by a solid state grinding method. In each case the doping metal varied from 2.5% to 20%. These catalysts exhibited higher activity and selectivity for ethane oxidative dehydrogenation (ODH) than conventionally prepared mixed oxides. Detailed characterisation was achieved using XRD, N2 adsorption, H2-TPR, SEM, TEM, and HAADF-STEM in order to study the detailed atomic structure and textural properties of the synthesized catalysts. Two kinds of typical structures are found in these mixed oxides, which are (major) “NixMyO” (M = Sn, Ti or W) solid solution phases (NiO crystalline structure with doping atom incorporated in the lattice) and (minor) secondary phases (SnO2, TiO2 or WO3). The secondary phase exists as a thin layer around small “NixMyO” particles, lowering the aggregation of nanoparticles during the synthesis. DFT calculations on the formation energies of M-doped NiO structures (M = Sn, Ti, W) clearly confirm the thermodynamic feasibility of incorporating these doping metals into NiO struture. The incorporation of doping metals into the NiO lattice decreases the number of holes (h+) localized on lattice oxygen (O2- + h+ ➔ O●-), which is the main reason for the improved catalytic performance (O●- is known to favor complete ethane oxidation to CO2). The high efficiency of ethylene production achieved in these particularly prepared mixed oxide catalysts indicates that the solid grinding method could serve as a general and practical approach for the preparation of doped NiO based catalysts.

  1. Styrene epoxidation with hydrogen peroxide over calcium oxide catalysts prepared from various precursors

    Institute of Scientific and Technical Information of China (English)

    Qingming Gu; Dan Han; Lei Shi; Qi Sun

    2012-01-01

    A series of CaO samples were prepared by calcination of commercially available and synthesis of calcium salt precursors such as calcium acetate,carbonate,hydroxide and oxalate etc.CaO samples were found to be effective for the epoxidation of styrene using hydrogen peroxide as an oxidant in the presence of acetonitrile.To determine the influence of the physicochemical properties and surface basicity on the catalytic activity,the prepared CaO samples were characterized using thermogravimetry (TG),X-ray diffraction (XRD),scanning electron microscopy (SEM),N2-adsorption and temperature-programmed desorption of CO2 (CO2-TPD).The results indicate that the amounts of very strong basic sites and high basicity strength on CaO sample are key factors for its excellent catalytic performance.In contrast,the surface area,porosity and the surface structure of CaO sample have a relatively minor effect on the catalytic activity.CaO sample,obtained by the decomposition of Ca(OH)2,prepared by precipitating calcium nitrate with sodium hydroxide in ethylene glycol solution,exhibits the highest amount of very strong basic sites and stronger strength of basic sites,and therefore it catalyses the epoxidation of styrene with the highest rate among the tested CaO samples.Under the selected reaction conditions,the selectivity of 97.5% to styrene oxide at a conversion in excess of 99% could be obtained.

  2. Preparation and characterization oF Ru-Sn/Al2O3 catalysts for the hydrogenation of fatty acid methyl esters

    Directory of Open Access Journals (Sweden)

    Vanina A. Mazzieri

    2010-01-01

    Full Text Available Ru-Sn/Al2O3 catalysts with different Sn loadings were prepared by the coimpregnation method. Several characterization techniques such as TPR, pyridine TPD and catalytic tests for dehydrogenation and hydrogenolysis were used to evaluate and compare such catalysts. TPR results indicate that Sn is deposited both onto the support and as species strongly interacting with Ru. Such non selective deposition modifies the acid and metallic functions of the catalysts. Both total acidity and acid strength distribution are affected: total acidity decreases and new sites of lower acid strength are created. Both dehydrogenating and hydrogenolytic activities are strongly diminished by the addition of Sn. Results of catalytic tests for methyl oleate hydrogenation indicate that methyl stearate is the main product, with only minute amounts of oleyl alcohol produced, and that the addition of Sn diminishes the hydrogenation activity.

  3. Research on Si-Al based catalysts prepared by complete liquid-phase method for DME synthesis in a slurry reactor

    Science.gov (United States)

    Li, Zhihong; Zuo, Zhijun; Huang, Wei; Xie, Kechang

    2011-01-01

    A series of Si-Al based DME synthesis catalysts were prepared by complete liquid-phase method and characterized by in situ XPS, XRD, N 2 adsorption and NH 3-TPD analyses. Based on the results, the addition of Si could adjust the pore structure and surface acidity of catalyst, exhibiting a strong promoting effect on the CO conversion and DME selectivity. However, when Si/Al ratio is higher, Si would cover active sites and increase the amount of strong acidity sites, causing the reduction in catalytic activity. It was found from in situ XPS characterization that Cu 0 is the active center of methanol synthesis in DME production, and the addition of Si changes the chemical surroundings of active components and weaken the interaction between Cu, Zn and Al, which maybe give rise to the decrease in catalyst stability.

  4. Preparation and characterization of Ru-Sn/Al{sub 2}O{sub 3} catalysts for the hydrogenation of fatty acid methyl esters

    Energy Technology Data Exchange (ETDEWEB)

    Mazzieri, Vanina A.; Sad, Mario R.; Vera, Carlos R.; Pieck, Carlos L. [Consejo Nacional de Investigaciones Cientificas y Tecnicas, Santa Fe (Argentina). Universidad Nacional del Litoral. Inst. de Investigaciones en Catalisis y Petroquimica; Grau, Ricardo [Consejo Nacional de Investigaciones Cientificas y Tecnicas, Santa Fe (Argentina). Universidad Nacional del Litoral. Inst. de Desarrollo Tecnologico para la Industria Quimica

    2010-07-01

    Ru-Sn/Al{sub 2}O{sub 3} catalysts with different Sn loadings were prepared by the coimpregnation method. Several characterization techniques such as TPR, pyridine TPD and catalytic tests for dehydrogenation and hydrogenolysis were used to evaluate and compare such catalysts. TPR results indicate that Sn is deposited both onto the support and as species strongly interacting with Ru. Such non selective deposition modifies the acid and metallic functions of the catalysts. Both total acidity and acid strength distribution are affected: total acidity decreases and new sites of lower acid strength are created. Both dehydrogenating and hydrogenolytic activities are strongly diminished by the addition of Sn. Results of catalytic tests for methyl oleate hydrogenation indicate that methyl stearate is the main product, with only minute amounts of oleyl alcohol produced, and that the addition of Sn diminishes the hydrogenation activity. (author)

  5. Preparation of biodiesel from cottonseed oil catalyzed by solid based catalyst%固体碱催化棉籽油制备生物柴油

    Institute of Scientific and Technical Information of China (English)

    姜绍通; 徐涟漪; 周勤丽; 潘丽军; 张福建; 张轶

    2011-01-01

    In order to study the related technology for preparing biodiesel by transesterification of cottonseed oil using solid based catalyst, with supported solid base Na3PO4/MgO as catalyst and biodiesel conversion rate as index, the optimum conditions for catalyst preparation were analyzed by single-factor and orthogonal experiments. The catalyst was characterized by methods of XRD, SEM and TG. Furthermore, the transesterification conditions from cottonseed oil to biodiesel were investigated using solid base catalyst. It was obtained that the optimum conditions for catalyst preparation were: 32% of Na3PO4 dosage on MgO, 600℃ of roasting temperature, 3 h of roasting time and 70℃ of blending temperature. Catalytic activity was related to Na3PO4 crystalline phase. The optimal conditions of transesterification with optimized catalyst were:2.5 h of reaction time, 70℃ of reaction temperature, 15:1 of mass ratio of methanol to oil, 5% of quality ratio of catalyst to oil.%为研究采用固体碱催化剂催化制备生物柴油的相关技术,以棉籽油为对象,选用Na3PO4/MgO负载型固体碱为催化剂,以棉籽油的生物柴油转换率为指标,通过单因素和正交试验,分析催化剂的最佳制备工艺,并对催化剂进行X射线衍射、扫描电镜和热重表征分析.在此基础上对该催化剂催化棉籽油制备生物柴油的工艺进行探讨.研究结果表明,催化剂的最佳制备工艺为:Na3PO4负载量32%,焙烧温度600℃,焙烧时间3 h,共混温度70℃;使用优选的催化剂制备生物柴油的工艺条件为:反应时间2.5h,反应温度70℃,醇油摩尔比15:1,催化剂用量5%;催化剂的活性与N%PO4晶相有关.

  6. A Facile Method for in Situ Preparation of the MnO2/LaMnO3 Catalyst for the Removal of Toluene.

    Science.gov (United States)

    Si, Wenzhe; Wang, Yu; Zhao, Shen; Hu, Fangyun; Li, Junhua

    2016-04-19

    MOx/ABO3 is a promising catalyst for the high-efficiency removal of volatile organic compounds. However, this catalyst is limited on practical applications due to its complex synthesis procedure and high cost. In this work, the MnO2/LaMnO3 catalyst was prepared in situ using a facile one-step method for the first time, in which partial La cations were selectively removed from three dimensionally chain-like ordered macroporous (3DOM) LaMnO3 material. After selective removal, the obtained MnO2/LaMnO3 sample expressed an excellent catalytic performance on toluene oxidation. Toluene could be completely oxidized into CO2 and H2O at 290 °C over the MnO2/LaMnO3 catalyst with a toluene/oxygen molar ratio of 1/100 and a space velocity of 120 000 mL/(g h). In addition, the apparent activation energy value of MnO2/LaMnO3 was 57 kJ/mol, which was lower than those of other metal oxides catalysts. According to O2-TPD and XPS results, it is concluded that the high catalytic performance of MnO2/LaMnO3 was mainly associated with the large amount of oxygen species and the excellent lattice oxygen mobility. MnO2/LaMnO3 is a promising catalyst for the practical removal of volatile organic compounds due to its high efficiency, good stability, low cost, and convenient preparation.

  7. Atmospheric-Pressure DBD Cold Plasma for Preparation of High Active Au/P25 Catalysts for Low-Temperature CO Oxidation

    Science.gov (United States)

    Di, Lanbo; Zhan, Zhibin; Zhang, Xiuling; Qi, Bin; Xu, Weijie

    2016-05-01

    Cold plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure was adopted for preparation of commercial TiO2 Degussa P25 supported Au catalysts (Au/P25-P) with the assistance of the deposition-precipitation procedure. The influences of the plasma reduction time and calcination on the performance of the Au/P25-P catalysts were investigated. CO oxidation was performed to investigate the catalytic activity of the Au/P25 catalysts. The results show that DBD cold plasma for the fabrication of Au/P25-P catalysts is a fast process, and Au/P25-P (4 min) exhibited the highest CO oxidation activity due to the complete reduction of Au compounds and less consumption of oxygen vacancies. In order to form more oxygen vacancies active species, Au/P25-P was calcined to obtain Au/P25-PC catalysts. Interestingly, Au/P25-PC exhibited the highest activity for CO oxidation among the Au/P25 samples. The results of transmission electron microscopy (TEM) indicated that the smaller size and high distribution of Au nanoparticles are the mean reasons for a high performance of Au/P25-PC. Atmospheric-pressure DBD cold plasma was proved to be of great efficiency in preparing high performance supported Au catalysts. supported by National Natural Science Foundation of China (Nos. 11505019, 21173028), the Science and Technology Research Project of Liaoning Provincial Education Department (No. L2013464), the Scientific Research Foundation for the Doctor of Liaoning Province (No. 20131004), and the Dalian Jinzhou New District Science and Technology Plan Project (No. KJCX-ZTPY-2014-0001)

  8. Towards ‘greener’ catalyst manufacture: Reduction of wastewater from the preparation of Cu/ZnO/Al2O3 methanol synthesis catalysts

    NARCIS (Netherlands)

    Prieto, G.; de Jong, K.P.; de Jongh, P.E.

    2013-01-01

    The generation of large volumes of nitrate-containing wastewater is a major issue in the industrial production of solid catalysts such as Cu/ZnO/Al2O3 employed in methanol synthesis. Extensive washing with water is needed to remove nitrate (and sodium) residues in the as-precipitated metal hydroxy-c

  9. Preparation and Characterization of Modified-ZrO2 Catalysts for the Reaction of CO Hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Qingjie Ge; A. Kiennemann; A.C. Roger; Wenzhao Li; Hengyong Xu

    2004-01-01

    ZrO2 in different structures and CexZr4-xO8 solid solutions have been prepared by a sol-gel related method with propionic acid as the solvent. The results of their characterization and CO hydrogenation performance evaluation show that t-ZrO2 has better catalytic performance for CO hydrogenation to hydrocarbon than m-ZrO2. Cerium (Ⅲ) acetate and zirconium (Ⅳ) acetylacetonate have been chosen as the most suitable starting materials for CexZr4-xO8 solid solution preparation. Ce-Zr reducibility properties are increased by the incorporation of zirconium oxide in the ceria structure. Ce2Zr2O8 exhibits a higher activity, lower methane selectivity and higher iso-C4 selectivity than tetragonal ZrO2. This implies that the formation mechanism of C4 hydrocarbons, especially that for the iso-C4 fraction is different over Ce2Zr2O8 and t-ZrO2.

  10. Recovery and Recycling of Ti Supported Bimodal Mesoporous Catalysts Prepared via Ship-in-a-bottle Method in the Epoxidation of Cyclohexene

    Institute of Scientific and Technical Information of China (English)

    Shiyang Bai; Xintao Hu; Jihong Sun⁎; Bo Ren; Jinpeng Wang

    2014-01-01

    Ti/BMMs (Ti supported bimodal mesoporous silica) catalysts have been prepared via self-assembly route com-bined with ship-in-a-bottle method. The recovery and recycling performances of Ti/BMMs were investigated in the epoxidation of cyclohexene. In order to the evaluate the regeneration methods and to examine the deactivation behaviors, the deactivated Ti/BMMs catalysts were washed in chloroform or calcinated at 450 °C for 6 h and then activity of the recovery catalysts were examined. Meanwhile, the structure features and surface properties of the regenerated catalysts were characterized by X-ray diffraction, N2-sorption analysis, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravi-metric analysis, UV visible spectroscopy and X-ray photoelectron spectroscopy. The results showed that the typical bimodal mesoporous structure of recycled Ti/BMMs catalysts was stil maintained, and the phenomenon of Ti leaching during the catalytic process and recovery was negligible. In particular, spectroscopic observations indicated that the effects of the regeneration methods on the tetrahedrally-coordinated Ti species and catalytic deactivation were remarkable. The main reasons were related to the polarities of used solvents during recovery tests, the environment medium of adsorbed water inside mesopore channels and the deposition of bulky mole-cules of by-products on the mesoporous surface.

  11. Innovative preparation of Au/C by replication of gold-containing mesoporous silica catalysts

    KAUST Repository

    Kerdi, Fatmé

    2010-01-01

    A new strategy, based on the nanocasting concept, has been used to prepare gold nanoparticles (NPs) highly dispersed in meso-structured carbons. Gold is first introduced in various functionalized mesostructured silicas (MCM-48 and SBA-15) and particles are formed inside the porosity upon reduction of Au 3+ cations. Silica pores are then impregnated with a carbon precursor and the composite material is heated at 900°C under vacuum. Silica is then removed by acid leaching, leading to partially encapsulated gold particles in mesoporous carbon. Carbon prevents aggregation of gold particles at high temperature, both the mean size and distribution being similar to those observed in silica. However, while Au@SiO2 exhibit significant catalytic activity in the aerobic oxidation of trans-stilbene in the liquid phase, its Au@C mesostructured replica is quite inactive. © 2010 Elsevier B.V. All rights reserved.

  12. A facile method for the preparation of Covalent Triazine Framework coated monoliths as catalyst support - applications in C1 catalysis

    KAUST Repository

    Bavykina, Anastasiya V.

    2017-07-17

    A quasi Chemical Vapour Deposition method for the manufacturing of well-defined Covalent Triazine Framework (CTF) coatings on cordierite monoliths is reported. The resulting supported porous organic polymer is an excellent support for the immobilisation of two different homogeneous catalysts: 1) an IrIIICp*-based catalyst for the hydrogen production from formic acid, and 2) a PtII-based for the direct activation of methane via Periana chemistry. The immobilised catalysts display a much higher activity in comparison with the unsupported CTF operated in slurry because of improved mass transport. Our results demonstrate that CTF based catalysts can be further optimised by engineering at different length-scales.

  13. Effect of the Pd/MWCNTs anode catalysts preparation methods on their morphology and activity in a direct formic acid fuel cell

    Science.gov (United States)

    Lesiak, B.; Mazurkiewicz, M.; Malolepszy, A.; Stobinski, L.; Mierzwa, B.; Mikolajczuk-Zychora, A.; Juchniewicz, K.; Borodzinski, A.; Zemek, J.; Jiricek, P.

    2016-11-01

    Impact of Pd/MWCNTs catalysts preparation method on the catalysts morphology and activity in a formic acid electrooxidation reaction was investigated. Three reduction methods of Pd precursor involving reduction in a high pressure microwave reactor (Pd1), reduction with NaBH4 (Pd2) and microwave-assisted polyol method (Pd3) were used in this paper. Crystallites size and morphology were studied using the scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), whereas elemental composition, Pd chemical state and functional groups content by the X-ray photoelectron spectroscopy (XPS). The prepared catalysts were tested in a direct formic acid fuel cell (DFAFC) as an anode material. The catalytic activity was correlated with a mean fraction of the total Pd atoms exposed at the surface (FE). The value of FE was calculated from the crystallites size distribution determined by the STEM measurements. Non-linear dependence of a current density versus FE, approaching the maximum at FE≈0.25 suggests that the catalytic process proceeded at Pd nanocrystallites faces, with inactive edges and corners. Pd2 catalyst exhibited highest activity due to its smallest Pd crystallites (3.2 nm), however the absence of Pd crystallites aggregation and low content of carbon in PdCx phase, i.e. x = 4 at.% may also affect the observed.

  14. Effect of preparation method on the surface characteristics and activity of the Pd/OMS-2 catalysts for the oxidation of carbon monoxide, toluene, and ethyl acetate

    Science.gov (United States)

    Liu, Lisha; Song, Yong; Fu, Zhidan; Ye, Qing; Cheng, Shuiyuan; Kang, Tianfang; Dai, Hongxing

    2017-02-01

    The cryptomelane-type manganese oxide octahedral molecular sieve (OMS-2)-supported Pd (0.5 wt% Pd/OMS-2-DP, 0.5 wt% Pd/OMS-2-PI, and 0.5 wt% Pd/OMS-2-EX) catalysts were prepared by the deposition-precipitation, pre-incorporation, and ion-exchanging strategies, respectively. It is shown that the preparation method exerted an important effect on the physicochemical property of the sample. Among the OMS-2-supported Pd catalysts, 0.5 wt% Pd/OMS-2-DP possessed the highest surface (Mn2+ + Mn3+)/Mn4+ atomic ratio and the highest surface Pd loading and acid sites. The 0.5 wt% Pd/OMS-2 catalysts outperformed the Pd-free counterpart, among which 0.5 wt% Pd/OMS-2-DP presented the best catalytic activity (T50% and T90% were 25 and 55 °C for CO oxidation, 240 and 285 °C for toluene oxidation, and 160 and 200 °C for ethyl acetate oxidation, respectively). We believe that the high Pd surface loading, high surface atomic ratio of (Mn2+ + Mn3+)/Mn4+, and good low-temperature reducibility, good oxygen mobility, and high acidity were responsible for the excellent performance of the 0.5 wt% Pd/OMS-2-DP catalyst.

  15. 3D-nanoarchitectured Pd/Ni catalysts prepared by atomic layer deposition for the electrooxidation of formic acid

    Directory of Open Access Journals (Sweden)

    Loïc Assaud

    2014-02-01

    Full Text Available Three-dimensionally (3D nanoarchitectured palladium/nickel (Pd/Ni catalysts, which were prepared by atomic layer deposition (ALD on high-aspect-ratio nanoporous alumina templates are investigated with regard to the electrooxidation of formic acid in an acidic medium (0.5 M H2SO4. Both deposition processes, Ni and Pd, with various mass content ratios have been continuously monitored by using a quartz crystal microbalance. The morphology of the Pd/Ni systems has been studied by electron microscopy and shows a homogeneous deposition of granularly structured Pd onto the Ni substrate. X-ray diffraction analysis performed on Ni and NiO substrates revealed an amorphous structure, while the Pd coating crystallized into a fcc lattice with a preferential orientation along the [220]-direction. Surface chemistry analysis by X-ray photoelectron spectroscopy showed both metallic and oxide contributions for the Ni and Pd deposits. Cyclic voltammetry of the Pd/Ni nanocatalysts revealed that the electrooxidation of HCOOH proceeds through the direct dehydrogenation mechanism with the formation of active intermediates. High catalytic activities are measured for low masses of Pd coatings that were generated by a low number of ALD cycles, probably because of the cluster size effect, electronic interactions between Pd and Ni, or diffusion effects.

  16. Preparation of β-Cyclodextrin Multi-Decorated Halloysite Nanotubes as a Catalyst and Nanoadsorbent for Dye Removal.

    Science.gov (United States)

    Cao, Xuan Thang; Showkat, Ali Md; Kim, Dong Woo; Jeong, Yeon Tae; Kim, Jong Su; Lim, Kwon Taek

    2015-11-01

    Hybrid materials of β-cyclodextrin multi-decorated halloysite nanotubes (HNTs-g-βCD) were prepared by a facile route, which showed high efficiency for catalysis and dye adsorption. Initially, the surface of halloysite nanotubes (HNTs) was modified with poly(glycidyl methacrylate) by the reversible addition fragmentation chain transfer (RAFT) polymerization of glycidyl methacrylate having epoxy groups as a monomer. Subsequently, β-cyclodextrin was conjugated with the modified HNTs to produce HNTs-g-βCD by the epoxide ring-opening reaction of mono-6-deoxy-6-hexanediamine-β-cyclodextrin. The nanocomposites were characterized by FT-IR, TGA, SEM, and TEM. The HNTs-g-βCD composites could be used as a nano adsorbent for methylene blue and a catalyst in the oxidation reaction of benzyl alcohol owing to the unique structure of β-cyclodextrin. The HNTs-g-βCD shows promiseas potential multi-functional materials by a combination of β-cyclodextrin and HNTs properties.

  17. Characterization of physicochemical properties of Pd/TiO{sub 2} nanostructured catalysts prepared by the photodeposition method

    Energy Technology Data Exchange (ETDEWEB)

    Camposeco, R. [Molecular Engineering Program, Instituto Mexicano del Petróleo, 07730 México, D.F. (Mexico); Department of Chemistry, UAM-A, 55534 México, D.F. (Mexico); Castillo, S., E-mail: scastill@imp.mx [Molecular Engineering Program, Instituto Mexicano del Petróleo, 07730 México, D.F. (Mexico); Department of Chemical Engineering, ESIQIE-IPN, 75876 México, D.F. (Mexico); Mejía-Centeno, Isidro; Navarrete, J.; Marín, J. [Molecular Engineering Program, Instituto Mexicano del Petróleo, 07730 México, D.F. (Mexico)

    2014-09-15

    In this work, the sol–gel and hydrothermal methods were used to synthesize TiO{sub 2}-nanostructured supports. The palladium supported on sol–gel TiO{sub 2} and on hydrothermal-method-TiO{sub 2} nanotubes was obtained by incorporating it through photodeposition. The characterization was performed by X-ray diffraction, transmission electron microscopy, N{sub 2} physisorption, pulse chemisorption, ultraviolet–visible absorption spectroscopy and X-ray photoelectron spectroscopy. Both sol–gel-palladium–TiO{sub 2} and palladium-nanotube samples showed different palladium dispersion and physicochemical properties. In the palladium-nanotube sample, high surface area (243 m{sup 2}/g), H{sub 2}Ti{sub 3}O{sub 7} stable phase, and low band gap energy (2.35 eV) were obtained. Palladium-nanotubes and palladium-TiO{sub 2}, used as reference samples, were prepared by wet impregnation. - Highlights: • The precursors of TiO{sub 2} nanotubes were synthesized by the sol–gel method. • TiO{sub 2} nanostructures showed improved textural and morphological properties. • Pd nanoparticles around 1 nm were obtained by the photodeposition method. • TiO{sub 2}-nanotube-based catalysts can be a powerful tool for facing air pollution.

  18. Degradable Polycaprolactone and Polylactide Homopolymer and Block Copolymer Brushes Prepared by Surface-Initiated Polymerization with Triazabicyclodecene and Zirconium Catalysts.

    Science.gov (United States)

    Grubbs, Joe B; Arnold, Rachelle M; Roy, Anandi; Brooks, Karson; Bilbrey, Jenna A; Gao, Jing; Locklin, Jason

    2015-09-22

    Surface-initiated ring-opening polymerization (SI-ROP) of polycaprolactone (PCL) and polylactide (PLA) polymer brushes with controlled degradation rates were prepared on oxide substrates. PCL brushes were polymerized from hydroxyl-terminated monolayers utilizing triazabicyclodecene (TBD) as the polymerization catalyst. A consistent brush thickness of 40 nm could be achieved with a reproducible unique crystalline morphology. The organocatalyzed PCL brushes were chain extended using lactide in the presence of zirconium n-butoxide to successfully grow PCL/PLA block copolymer (PCL-b-PLA) brushes with a final thickness of 55 nm. The degradation properties of "grafted from" PCL brush and the PCL-b-PLA brush were compared to "grafted to" PCL brushes, and we observed that the brush density plays a major role in degradation kinetics. Solutions of methanol/water at pH 14 were used to better solvate the brushes and increase the kinetics of degradation. This framework enables a control of degradation that allows for the precise removal of these coatings.

  19. 3D-nanoarchitectured Pd/Ni catalysts prepared by atomic layer deposition for the electrooxidation of formic acid.

    Science.gov (United States)

    Assaud, Loïc; Monyoncho, Evans; Pitzschel, Kristina; Allagui, Anis; Petit, Matthieu; Hanbücken, Margrit; Baranova, Elena A; Santinacci, Lionel

    2014-01-01

    Three-dimensionally (3D) nanoarchitectured palladium/nickel (Pd/Ni) catalysts, which were prepared by atomic layer deposition (ALD) on high-aspect-ratio nanoporous alumina templates are investigated with regard to the electrooxidation of formic acid in an acidic medium (0.5 M H2SO4). Both deposition processes, Ni and Pd, with various mass content ratios have been continuously monitored by using a quartz crystal microbalance. The morphology of the Pd/Ni systems has been studied by electron microscopy and shows a homogeneous deposition of granularly structured Pd onto the Ni substrate. X-ray diffraction analysis performed on Ni and NiO substrates revealed an amorphous structure, while the Pd coating crystallized into a fcc lattice with a preferential orientation along the [220]-direction. Surface chemistry analysis by X-ray photoelectron spectroscopy showed both metallic and oxide contributions for the Ni and Pd deposits. Cyclic voltammetry of the Pd/Ni nanocatalysts revealed that the electrooxidation of HCOOH proceeds through the direct dehydrogenation mechanism with the formation of active intermediates. High catalytic activities are measured for low masses of Pd coatings that were generated by a low number of ALD cycles, probably because of the cluster size effect, electronic interactions between Pd and Ni, or diffusion effects.

  20. Bismuth Molybdate Catalysts Prepared by Mild Hydrothermal Synthesis: Influence of pH on the Selective Oxidation of Propylene

    Directory of Open Access Journals (Sweden)

    Kirsten Schuh

    2015-09-01

    Full Text Available A series of bismuth molybdate catalysts with relatively high surface area was prepared via mild hydrothermal synthesis. Variation of the pH value and Bi/Mo ratio during the synthesis allowed tuning of the crystalline Bi-Mo oxide phases, as determined by X-ray diffraction (XRD and Raman spectroscopy. The pH value during synthesis had a strong influence on the catalytic performance. Synthesis using a Bi/Mo ratio of 1/1 at pH ≥ 6 resulted in γ-Bi2MoO6, which exhibited a better catalytic performance than phase mixtures obtained at lower pH values. However, a significantly lower catalytic activity was observed at pH = 9 due to the low specific surface area. γ-Bi2MoO6 synthesized with Bi/Mo = 1/1 at pH = 6 and 7 exhibited relatively high surface areas and the best catalytic performance. All samples prepared with Bi/Mo = 1/1, except samples synthesized at pH = 1 and 9, showed better catalytic performance than samples synthesized with Bi/Mo = 2/3 at pH = 4 and 9 and γ-Bi2MoO6 synthesized by co-precipitation at pH = 7. At temperatures above 440 °C, the catalytic activity of the hydrothermally synthesized bismuth molybdates started to decrease due to sintering and loss of surface area. These results support that a combination of the required bismuth molybdate phase and a high specific surface area is crucial for a good performance in the selective oxidation of propylene.

  1. Preparation of Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2}/cotton catalysts for decomposition of formaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xuehua; He, Junhui, E-mail: jhhe@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials (China); Wang, Donghui [Research Institute of Chemical Defense (China); Hu, Yucai [Ludong University, School of Chemistry and Materials Science (China); Tian, Hua [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials (China); Dong, Tongxin [Research Institute of Chemical Defense (China); He, Zhicheng [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials (China)

    2013-08-15

    Powder Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2} and Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2}/cotton catalysts were successfully prepared by facile methods. The as-prepared catalysts were characterized by means of XRD, SEM, TEM, and TGA. Au{sub 0.5}Pt{sub 0.5} alloy NPs were evenly dispersed on the surface of nest-like MnO{sub 2} and no agglomeration was observed. The powder Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2} catalyst was adhered to the surface of cotton fibers, and the practical loading amount first increases, and then levels off with increase of the theoretical loading dosage. The Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2}/cotton catalysts showed excellent catalytic activities for oxidative decomposition of formaldehyde (HCHO). 15 wt% Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2}/cotton has the highest catalytic activity and the temperature for complete decomposition of HCHO is 120 Degree-Sign C. The valence states of MnO{sub 2}, MnO{sub 2} porous structures, synergistic effect between Au{sub 1-x}Pt{sub x} NPs and MnO{sub 2}, and synergistic effect between Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2} and cotton are considered to be the main reasons for the observed high catalytic activity of Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2}/cotton catalysts. The Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2}/cotton catalysts can not only avoid the disadvantages of power catalysts but also improve the catalytic activity; these advantages indicate that Au{sub 0.5}Pt{sub 0.5}/MnO{sub 2}/cotton catalysts have promising potentials in practical applications.Graphical Abstract.

  2. Hydrocarbon conversion catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, A.; Huizinga, T.; Maxwell, I.E.

    1989-08-15

    This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting a hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.35A, a water absorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of at least 8% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; an alumina binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

  3. Influence of HF catalyst on the microstructure properties of ultra low-k thin films prepared by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    He Zhi-Wei; Xu Da-Yin; Jiang Xiang-Hua; Wang Yin-Yue

    2008-01-01

    This paper reports that by using the hydrofluoric acid (HF) as the acid catalyst, F doped nanoporous low-k SiO2 thin films have been prepared by means of sol-gel method. The characterization of atomic force microscopy and Fourier transform infrared spectroscopy demonstrates that the HF catalyzed films are more hydrophobic. The N2 adsorption/desorption experiments show that the suited introduction of HF increases the porosity and decreases the pore size distribution (about 10 nm) in the films. The above results indicate that the hydrofluoric acid is the more suitable acid catalyst than the hydrochloric one for preparing nanoporous ultra low-k SiO2 thin films.

  4. Superacid Catalyst SO42-/ZrO2-La2O3 Prepared by Ultrasonic Co-precipitation and Low Temperature Aging

    Institute of Scientific and Technical Information of China (English)

    Tong-yun Chen; Xiang-feng Chu; Ke-liang Hu

    2009-01-01

    Sulfated zirconia-lanthana (SO42-/ZrO2-La2O3) precursors were prepared by ultrasonic co-precipitation method and followed by aging at different temperature. The precursors were treated by 0.5 mol/L H2SO4. Samples of SO42-/ZrO2-La2O3 nano-crystalline catalysts were obtained by baking the treated precursors at different temperatures. The acidic properties of SO42-/ZrO2-La2O3were tested by the Hammett indicator method. The phase composition, specific area, particle structure, and surface state were characterized by X-ray diffraction, BET, transmission electron microscopy, infrared spectrum, and X-ray photoelectron spec-troscopy. The catalytic activities were estimated by esterification of acetic acid with glycerin. It was shown that the catalyst prepared by ultrasonic stirring and low temperature (-15℃) exhibited highly active sites and high catalytic property.

  5. Superior DeNOx activity of V2O5–WO3/TiO2 catalysts prepared by deposition–precipitation method

    DEFF Research Database (Denmark)

    Putluru, Siva Sankar Reddy; Schill, Leonhard; Gardini, Diego

    2014-01-01

    electron microscopy, H2-temperature programmed reduction and NH3-temperature programmed desorption. The catalysts exhibited only crystalline TiO2 phases with the active metal and promoter in highly dispersed or amorphous state. The 3 wt% V2O5–10 wt% WO3/TiO2 catalyst prepared by DP using ammonium carbamate...

  6. B(HSO43: An efficient and recyclable catalyst for the preparation of substituted Friedländer quinoline synthesis

    Directory of Open Access Journals (Sweden)

    Saghanezhad Seyyed Jafar

    2013-01-01

    Full Text Available Substituted quinolines have been synthesized in the presence of catalytic amounts of boron sulfonic acid (BSA in solvent-free conditions. This methodology offers some advantages including high yield, short reaction time, low cost of the catalyst, green conditions by avoiding toxic solvents and recoverable catalyst.

  7. A Model gamma-Alumina-Supported Rhenium-Platinum Catalyst Prepared from [Re2Pt(CO)12]: 1. Synthesis and Spectroscopic Characterization.

    NARCIS (Netherlands)

    Koningsberger, D.C.; Fung, A.S.; McDeVitt, M.R.; Tooley, P.A.; Kelley, M.J.; Gates, B.C.

    1993-01-01

    Catalysts supported on -Al2O3 were prepared from [Re2Pt(CO)12], and from Pt (NH3)4(NO3)2 and NH4ReO4. The former samples were characterized by infrared and X-ray photoelectron spectroscopies (XPS) and by temperature-programmed reduction (TPR); the latter were characterized by TPR. [Re2Pt(CO)12] was

  8. Preparation of Ni/HKUST-1 catalyst by ultrasonic method%超声法制备Ni/HKUST-1催化剂

    Institute of Scientific and Technical Information of China (English)

    刘文通; 张达菲; 牛亚; 张小勤; 魏子衿; 曹文秀

    2015-01-01

    HKUST-1 catalyst as one of the hot research spots of nano materials has excellent surface prop-erties,but pure metal-organic framework( MOFs)materials used as the catalysts in catalytic field have no obvious catalytic effect. The synergistic effects among the different metals are expected to improve the catalytic performance of the material,so it is necessary to modify the surface of MOFs materials. In this paper,nickel was loaded on the surface of HKUST-1 catalyst by using ultrasonic method,excessive im-pregnation method and sol-gel method,and then the performance of the as-prepared HKUST-1 catalyst were investigated by means of atom spectrophotometer. The experimental results showed that HKUST-1 catalyst prepared by ultrasonic method possessed the best performance.%HKUST-1催化剂作为当今纳米材料研究的热点之一,具有优良的表面性能.而在催化领域方面,使用金属-有机骨架( MOFs)材料作为催化剂的催化效果不是很明显,利用不同金属之间的协同作用有望提高该材料的催化性能,有必要对MOFs的表面进行修饰.采用超声法、过量浸渍法和溶胶-凝胶法在HKUST-1催化剂表面负载金属Ni,并利用原子分光光度计检测3种方法的负载性能,结果表明,超声法的负载性能最好.

  9. Production of hydrogen from methanol over Cu/ZnO and Cu/ZnO/Al2O3 catalysts prepared by homogeneous precipitation : Steam reforming and oxidative steam reforming

    OpenAIRE

    2006-01-01

    Two series of Cu/ZnO and Cu/ZnO/Al2O3 catalysts with varying Cu/Zn ratio have been prepared by the homogeneous precipitation (hp) method using urea hydrolysis. Steam reforming and oxidative steam reforming of methanol were performed using the hp-Cu/Zn-based catalysts for catalytic production of hydrogen. The hp-Cu/ZnO/Al2O3 catalyst showed a higher activity than the hp-Cu/ZnO catalysts. In both cases, the catalytic activity was well correlated with the surface area of Cu metal, and the maximu...

  10. Facile preparation of magnetic mesoporous Fe3O4/C/Cu composites as high performance Fenton-like catalysts

    Science.gov (United States)

    Li, Keyan; Zhao, Yongqin; Janik, Michael J.; Song, Chunshan; Guo, Xinwen

    2017-02-01

    Fe-Cu composites with different compositions and morphologies were synthesized by a hydrothermal method combined with precursor thermal transformation. γ-Fe2O3/CuO and α-Fe2O3/CuO were obtained by calcining the Fe and Cu tartrates under air atmosphere at 350 °C and 500 °C, respectively, while Fe3O4/C/Cu was obtained by calcining the tartrate precursor under N2 atmosphere at 500 °C. The Fe3O4/C/Cu composite possessed mesoporous structure and large surface area up to 133 m2 g-1. The Fenton catalytic performance of Fe3O4/C/Cu composite was closely related to the Fe/Cu molar ratio, and only proper amounts of Fe and Cu exhibited a synergistic enhancement in Fenton catalytic activity. Cu inclusion reduced Fe3+ to Fe2+, which accelerated the Fe3+/Fe2+ cycles and favored H2O2 decomposition to produce more hydroxyl radicals for methylene blue (MB) oxidation. Due to the photo-reduction of Fe3+ and Cu2+, the Fenton catalytic performance was greatly improved when amending with visible light irradiation in the Fe3O4/C/Cu-H2O2 system, and MB (100 mg L-1) was nearly removed within 60 min. The Fe3O4/C/Cu composite showed good recyclability and could be conveniently separated by an applied magnetic field. Compared with conventional methods for mesoporous composite construction, the thermolysis method using mixed metal tartrates as precursors has the advantages of easy preparation and low cost. This strategy provides a facile, cheap and green method for the synthesis of mesoporous composites as excellent Fenton-like catalysts, without any additional reductants or organic surfactants.

  11. CO oxidation activity of Cu-CeO2 nano-composite catalysts prepared by laser vaporization and controlled condensation

    Science.gov (United States)

    Sundar, Rangaraj S.; Deevi, Sarojini

    2006-08-01

    Ceria supported copper catalysts were synthesized by laser vaporization and controlled condensation method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX) and temperature programmed reduction (TPR). The catalytic activity of the nanopowders for CO oxidation reaction was tested in a fixed bed flow tube reactor in Ar-20%O2-4%CO mixture. Irrespective of the copper content, the catalytic activity of the nanopowders is similar in the initial CO test, and the catalytic activity improves (i.e. the light-off temperature decreases) during a subsequent run. The lowest light-off temperature during the second run is recorded in the material with 20% copper. TEM studies on 20%Cu-CeO2 sample in the as-prepared condition and after CO test exhibit two types of ceria particles namely, polygonal particles 3-5 nm in size and spherical particles of 15-20 nm in size. Rapid cooling of the nanoparticles formed during the laser ablation results in incorporation of a large amount of copper within the ceria as solid solution. Presence of solid solution of copper is confirmed by EDAX and electron diffraction analyses. In addition, copper-rich surface layer of Cu2O is found over the spherical particles. The cerium oxide components are essentially identical before and after CO test, except that the polygonal CeO2 particles contain newly formed fine crystals of CuO. TPR results reveal two reduction peaks, which further supports, the presence of two different copper species in the material. The shift in light-off temperature during the second run is attributed to the synergistic interaction between newly formed CuO crystals with the CeO2 matrix.

  12. Method of preparing and utilizing a catalyst system for an oxidation process on a gaseous hydrocarbon stream

    Science.gov (United States)

    Berry, David A; Shekhawat, Dushyant; Smith, Mark; Haynes, Daniel

    2013-07-16

    The disclosure relates to a method of utilizing a catalyst system for an oxidation process on a gaseous hydrocarbon stream with a mitigation of carbon accumulation. The system is comprised of a catalytically active phase deposited onto an oxygen conducting phase, with or without supplemental support. The catalytically active phase has a specified crystal structure where at least one catalytically active metal is a cation within the crystal structure and coordinated with oxygen atoms within the crystal structure. The catalyst system employs an optimum coverage ratio for a given set of oxidation conditions, based on a specified hydrocarbon conversion and a carbon deposition limit. Specific embodiments of the catalyst system are disclosed.

  13. Comparison of preparation methods for ceria catalyst and the effect of surface and bulk sulfates on its activity toward NH3-SCR.

    Science.gov (United States)

    Chang, Huazhen; Ma, Lei; Yang, Shijian; Li, Junhua; Chen, Liang; Wang, Wei; Hao, Jiming

    2013-11-15

    A series of CeO2 catalysts prepared with sulfate (S) and nitrate (N) precursors by hydrothermal (H) and precipitation (P) methods were investigated in selective catalytic reduction of NOx by NH3 (NH3-SCR). The catalytic activity of CeO2 was significantly affected by the preparation methods and the precursor type. CeO2-SH, which was prepared by hydrothermal method with cerium (IV) sulfate as a precursor, showed excellent SCR activity and high N2 selectivity in the temperature range of 230-450 °C. Based on the results obtained by temperature-programmed reduction (H2-TPR), transmission infrared spectra (IR) and thermal gravimetric analysis (TGA), the excellent performance of CeO2-SH was correlated with the surface sulfate species formed in the hydrothermal reaction. These results indicated that sulfate species bind with Ce(4+) on the CeO2-SH catalyst, and the specific sulfate species, such as Ce(SO4)2 or CeOSO4, were formed. The adsorption of NH3 was promoted by these sulfate species, and the probability of immediate oxidation of NH3 to N2O on Ce(4+) was reduced. Accordingly, the selective oxidation of NH3 was enhanced, which contributed to the high N2 selectivity in the SCR reaction. However, the location of sulfate on the CeO2-SP catalyst was different. Plenty of sulfate species were likely deposited on CeO2-SP surface, covering the active sites for NO oxidation, which resulted in poor SCR activity in the test temperature range. Moreover, the resistance to alkali metals, such as Na and K, was improved over the CeO2-SH catalyst.

  14. Ni/SiO2 Catalyst Prepared with Nickel Nitrate Precursor for Combination of CO2 Reforming and Partial Oxidation of Methane: Characterization and Deactivation Mechanism Investigation

    Directory of Open Access Journals (Sweden)

    Sufang He

    2015-01-01

    Full Text Available The performance of Ni/SiO2 catalyst in the process of combination of CO2 reforming and partial oxidation of methane to produce syngas was studied. The Ni/SiO2 catalysts were prepared by using incipient wetness impregnation method with nickel nitrate as a precursor and characterized by FT-IR, TG-DTA, UV-Raman, XRD, TEM, and H2-TPR. The metal nickel particles with the average size of 37.5 nm were highly dispersed over the catalyst, while the interaction between nickel particles and SiO2 support is relatively weak. The weak NiO-SiO2 interaction disappeared after repeating oxidation-reduction-oxidation in the fluidized bed reactor at 700°C, which resulted in the sintering of metal nickel particles. As a result, a rapid deactivation of the Ni/SiO2 catalysts was observed in 2.5 h reaction on stream.

  15. Phase Composition of Ni/Mg1−xNixO as a Catalyst Prepared for Selective Methanation of CO in H2-Rich Gas

    Directory of Open Access Journals (Sweden)

    Mengmeng Zhang

    2015-01-01

    Full Text Available Supported Ni catalysts Ni/Mg1−xNixO were prepared by reducing samples NiO-MgO in H2/N2 mixture gas at 500°C~800°C for selective methanation of CO in H2-rich gas (CO-SMET. The samples NiO-MgO were obtained by heating water slurry of MgO and Ni(NO32 in a rotary evaporator at 80°C and a final calcination in air at 400°C~800°C. X-ray diffraction (XRD and temperature programmed reduction (TPR measurements demonstrate that the samples NiO-MgO were composed of solid solution Mg1−yNiyO as the main phase and a minor amount of NiO at calcination temperature of 400°C, and amount of the NiO was decreased as calcination temperature increased. Phase composition of the catalysts Ni/Mg1−xNixO was estimated by the Rietveld method. Effects of reduction temperature, feed Ni/Mg ratio, and calcination temperature on phase composition and catalytic activity of the catalysts were investigated. It is clear that CO conversion was generally enhanced by an increased amount of metallic Ni of the catalysts.

  16. Hydrocraquage sous pression d'une huile de soja : procédé d'étude et allure générale de la transformation Soybean Oil Hydrocracking under Pressure: Process and General Aspect of the Transformation

    Directory of Open Access Journals (Sweden)

    Nunes P. P.

    2006-11-01

    types of hydrocracking used were thermal hydrocracking and hydrocracking in the presence of an oxide or of a dualfunction catalyst (hydrogenating/cracking. In the latter case, hydrogenation of the double bonds of the lateral chains of triglycerides was observed during the heating of the reactor to about 673 K, at which temperature actual hydrocracking begins. At this temperature, the decarbonylation/decarboxylation of fatty acids (coming from the cleavage of the ester bonds of the triglycerides is observed together with a marked hydrogenolysis in the presence of a metal catalyst. The main result of this is the production of alkanes having the same linear structure as that of the initial fatty acids. The overall weight percent of conversion may reach 83% under the right temperature and pressure conditions, including the percent of gas fraction (CO, CO2, C1-C4.

  17. Photodegradation of indigo carmine and methylene blue dyes in aqueous solution by SiC-TiO{sub 2} catalysts prepared by sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Solis, Christian [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Juarez-Ramirez, Isaias, E-mail: isajua13@yahoo.com [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Moctezuma, Edgar [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Torres-Martinez, Leticia M. [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer Photodegradation of organic dyes is possible using sol-gel SiC-TiO{sub 2} catalysts. Black-Right-Pointing-Pointer SiC-TiO{sub 2} makes a synergy effect that enhances its catalytic activity. Black-Right-Pointing-Pointer Sol-gel allows good dispersion and attachment of TiO{sub 2} particles on SiC surface. Black-Right-Pointing-Pointer SiC-TiO{sub 2} exhibits better activity than TiO{sub 2} (P25) on organic dyes degradation. Black-Right-Pointing-Pointer SiC-TiO{sub 2} catalysts are settled down and easily separated after photocatalysis. - Abstract: Indigo carmine and methylene blue dyes in aqueous solution were photodegraded using SiC-TiO{sub 2} catalysts prepared by sol-gel method. After thermal treatment at 450 Degree-Sign C, SiC-TiO{sub 2} catalysts prepared in this work showed the presence of SiC and TiO{sub 2} anatase phase. Those compounds showed specific surface area values around 22-25 m{sup 2} g{sup -1}, and energy band gap values close to 3.05 eV. In comparison with TiO{sub 2} (P25), SiC-TiO{sub 2} catalysts showed the highest activity for indigo carmine and methylene blue degradation, but this activity cannot be attributed to the properties above mentioned. Therefore, photocatalytic performance is due to the synergy effect between SiC and TiO{sub 2} particles caused by the sol-gel method used to prepare the SiC-TiO{sub 2} catalysts. TiO{sub 2} nanoparticles are well dispersed onto SiC surface allowing the transfer of electronic charges between SiC and TiO{sub 2} semiconductors, which avoid the fast recombination of the electron-hole pair during the photocatalytic process.

  18. Commercial Application of RMC Technology in the 1.5 Mt/a Hydrocracking Unit at Shanghai Petrochemical Company

    Institute of Scientific and Technical Information of China (English)

    Xiong Zhenlin; Wang Yiguan; Zhang Maoying; Lin Baohua; Mao Yichao

    2003-01-01

    The RMC technology developed by RIPP has been applied in a 1.5 Mt/a medium pressure hydrocracking unit at Shanghai Petrochemical Company. The unit was successfully put on stream in September 2002. Calibration of the performance of the commercial unit has shown that the RMC technology has higher hydrogenation activity and selectivity, and high quality product can be obtained under lower reaction temperature. The heavy naphtha with less than 0.5 ppm of sulfur and 58.5 m% potential aromatic content is a good feedstock for catalytic reforming unit. The diesel with less than 0.5 ppm of sulfur, 6.6 m% aromatics and cetane rating of 56 is a high-grade diesel fuel. The hydrocracked tail oil containing more than 14 m% hydrogen and mere 1.7m% aromatics could be used as a good feedstock for steam cracking process to produce ethylene.

  19. Performance of Fe-Cr based WGS catalysts prepared by co-precipitation and oxi-precipitation methods

    Energy Technology Data Exchange (ETDEWEB)

    Marono, M.; Ruiz, E.; Sanchez, J.M. [CIEMAT, Energy Department, Combustion and Gasification Division, Avda Complutense, 22, 28040 Madrid (Spain); Martos, C.; Dufour, J.; Ruiz, A. [URJC, Department of Chemical and Environmental Technology, ESCET, C/Tulipan, s/n, 28933, Mostoles, Madrid (Spain)

    2009-11-15

    In this work the performance of Fe-Cr based WGS catalysts synthesized following two different methods (co-precipitation and oxy-precipitation) is studied under a wide range of operating conditions. A commercial Fe-Cr based WGS catalyst is used for comparison. The activity of the catalysts has been studied on simulated gases under conditions typical of oxygen pressurized gasification. The influence of main operating parameters, including temperature, space velocity and excess steam is evaluated in terms of hydrogen production and CO conversion. Catalytic performance has been evaluated from 200 C to 500 C, using gas space velocities between 2885 and 10000 h{sup -1} and steam to carbon monoxide ratios from 2 to 6.7. According to the results obtained in this work, the oxy-precipitation method has provided a suitable approach to synthesize highly active Fe-Cr based WGS catalysts. (author)

  20. Preparation of MCM-41-supported chiral Salen Mn (Ⅲ) catalysts and their catalytic properties in the asymmetric epoxidation of olefins

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A secondary amino-modified mesoporous molecular sieve MCM-41 was obtained by reaction of bis(3-(triethoxysilyl)propyl)amine with MCM-41. The chiral Salen-Mn (Ⅲ) complex was anchored onto the modified MCM-41 by a multi-step grafting method and two heterogenized catalysts with different Mn contents were obtained. The catalysts were characterized by XRD, N2 adsorption, ICP, FT-IR and DR UV-Vis. Their catalysis on asymmetric epoxidation of several olefins was studied with NaClO and m-CPBA as oxidants respectively. It was found that both the activity and enantioselectivity of the catalysts decreased after the homogeneous catalyst was heterogenized. The reasons resulting in the decrease of catalytic performance were discussed.

  1. Selective catalytic reduction of NO with NH3 over CeO2-ZrO2-WO3 catalysts prepared by different methods

    Science.gov (United States)

    Ning, Ping; Song, Zhongxian; Li, Hao; Zhang, Qiulin; Liu, Xin; Zhang, Jinhui; Tang, Xiaosu; Huang, Zhenzhen

    2015-03-01

    The selective catalytic reduction (SCR) of NO by NH3 has been investigated over the CeO2-ZrO2-WO3 (CZW) catalysts prepared by hydrothermal synthesis, incipient impregnation, co-precipitation and sol-gel methods. The results indicate that the CZW catalyst prepared by hydrothermal method shows the best SCR activity, and more than 90% NO conversion is obtained at 195-450 °C with a gas hourly space velocity of 50,000 h-1. The samples are characterized by XRD, N2 adsorption-desorption, SEM, EDS, XPS, H2-TPR, NH3-TPD and Pyridine-IR techniques. The results imply that the superior SCR activity of CZW catalyst is contributed to the excellent redox property, strong acidity and highest content of chemisorbed oxygen species. Furthermore, the larger surface area and greater total pore volume improve the redox ability and enhance NO conversion at low temperature, while the co-existence of Lewis and Brønsted acid sites enhance the SCR activity at high temperature.

  2. Preparation of highly dispersed Ru-Sn bimetallic supported catalysts from the single source precursors Cp(PPh32Ru-SnX3 (X = Cl or Br

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Bernardes Silva

    2003-06-01

    Full Text Available In this work highly dispersed Ru-Sn bimetallic catalysts have been prepared from organobimetallic Cp(PPh32Ru-SnX3 (X = Cl or Br complexes. These single source precursors can be easily impregnated in high surface area supports, such as activated carbon and sol-gel SiO2, and upon controlled thermal treatment the ligands are released as volatile products resulting in the formation of the bimetallic system Ru-Sn. Catalytic reactions, such as hydrodechlorination of CCl4 and chlorobenzene and TPR (Temperature Programmed Reduction experiments carried out with these RuSn catalysts suggested a strong interaction between Ruthenium and Tin. Mössbauer measurements showed that these materials when exposed to air are immediately oxidized to form Sn (IV. It was shown that upon controlled reduction conditions with H2 it is possible to reduce selectively Sn to different oxidation states and different phases. The Sn oxidation state showed significant effect on the catalytic hydrogenation of 1,5-cyclooctadiene. The use of these single source precursors with a controlled decomposition/reduction procedure allows the preparation of unique catalysts with an intimate interaction between the components ruthenium and tin and the possibility of varying the Sn oxidation state around the Ru metal.

  3. Baize-like CeO2 and NiO/CeO2 nanorod catalysts prepared by dealloying for CO oxidation

    Science.gov (United States)

    Zhang, Xiaolong; Li, Kun; Shi, Wenyu; Wei, Caihua; Song, Xiaoping; Yang, Sen; Sun, Zhanbo

    2017-01-01

    Baize-like monolithic CeO2 and NiO/CeO2 nanorod catalysts were prepared by combined dealloying and calcination and the catalytic activities were evaluated using CO catalytic oxidation. The CeO2 catalysts were composed of nanorods and exhibited a three-dimensional supporting structure with pores. After introduction of NiO, dispersed NiO nanosheets and nanoparticles were supported on the surface of CeO2 nanorods and they were not well-crystallined due to CeO2 inhibiting the NiO crystallization. The Raman and x-ray photoelectron spectroscopy analyses revealed that the introduction of NiO species into CeO2 generated more coordinate unsaturated Ni atoms, oxygen vacancies, defects and active sites for CO catalytic reactions. The reaction activation energy of NiO/CeO2 nanorod catalyst prepared from the Al83Ce10Ni7 precursor alloy was just 31.2 kJ mol-1 and the CO conversion can reach up to 97% at 240 °C, which was superior to that of pure CeO2 and nanoporous NiO. The enhanced catalytic activity of baize-like NiO/CeO2 nanorods can be attributed to the strong synergistic effects between finely dispersed NiO species and surface oxygen vacancies in CeO2 nanorods.

  4. Preparation of IrO2 nanoparticles with SBA-15 template and its supported Pt nanocomposite as bifunctional oxygen catalyst

    Science.gov (United States)

    Kong, Fan-Dong; Liu, Jing; Ling, Ai-Xia; Xu, Zhi-Qiang; Wang, Hui-Yun; Kong, Qing-Sheng

    2015-12-01

    In the present work, we report the syntheses of IrO2 nanoparticles with SBA-15 template (s-IrO2), and s-IrO2 supported Pt nanocomposite (Pt/s-IrO2) as bifunctional oxygen catalyst. Physical characterizations including X-ray diffraction and transmission electron microscopy demonstrate that s-IrO2 catalyst has excellent uniformity and regularity in particle shape and much ordered distribution in geometric space, and Pt/s-IrO2 catalyst shows a uniform Pt dispersion on the surface of the s-IrO2 particles. Electrochemical analyses prove that s-IrO2 catalyst possesses superior OER activity at operating potentials; and that Pt/s-IrO2 catalyst, in comparison to Pt/commercial IrO2, has higher ESA value and ORR catalytic performance with a mechanism of four-electron pathway and a high ORR efficiency. And as a bifunctional oxygen catalyst, Pt/s-IrO2 also exhibits more remarkable OER performance than the commercial one. The s-IrO2 nanoparticles will be a promising active component (for OER), and suitable for Pt support (for ORR).

  5. Microporous Zeolites as Catalysts for the Preparation of Decyl Glucoside from Glucose with 1-Decanol by Direct Glucosidation

    Directory of Open Access Journals (Sweden)

    Kyong-Hwan Chung

    2016-12-01

    Full Text Available The catalytic properties of microporous zeolite catalysts were evaluated in the synthesis of decyl glucoside from glucose with 1-decanol by direct glucosidation. The effects of the acidic properties and pore structure of the zeolite catalysts on the glucose conversions and decyl glucoside yields were investigated. The conversions of glucose on the H+ ion-exchanged FAU, MFI, and BEA zeolite catalysts were above 70%. The conversion increased with decreasing acid strength of the catalysts. The highest conversion and yield of decyl glucoside were exhibited on the H-FAU(3 zeolite catalyst. The catalytic activities were enhanced with increasing amounts of acid sites. The selectivity of decyl glucopyranoside increased with decreasing Si/Al values for the same zeolite catalysts. The pore structure of H-FAU zeolite would allow sufficient spatial restriction to produce decyl glucopyranoside through the isomerization of decyl glucofuranoside into decyl glucopyranoside in its extensive pore channels. The selectivities of the decyl glucoside isomers relied significantly on the restricted transition state to the primary products due to their pore topologies.

  6. Preparation and properties of nanophase (Ce, Zr, PrO2-doped alumina coating on cordierite ceramic honeycomb for three-way catalysts

    Directory of Open Access Journals (Sweden)

    Jiuying Tian

    2012-03-01

    Full Text Available Nanophase (Ce, Zr, PrO2-doped alumina coatings were prepared by impregnating the cordierite ceramic honeycomb in the sol or in the slurry of already calcined powder, respectively. The effects of preparation methods on the crystal phase, texture, oxygen storage capacity (OSC, reducibility, surface morphology and thermal stability of coatings were investigated by X-ray diffraction (XRD, the Brunauer Emmet Teller (BET method, the oxygen pulsing technique, H2-temperature-programmed reduction (H2-TPR and scanning electron microscopy (SEM. These nanophase (Ce, Zr, PrO2-doped alumina coatings were used as supports to prepare Pd-only three-way catalysts, and evaluated with respect to catalytic activities. The results indicate that the nanophase (Ce, Zr, PrO2-doped alumina coatings prepared by the two methods have high thermal stability. However, the coating derived from the sol shows better crystalline structure, texture, reducibility and oxygen storage capacity than the coating derived from the slurry. SEM observation shows that the morphology of the coating derived from the sol is uniform and smooth. The Pd-only catalyst derived from the sol exhibits high three-way catalytic activity at low temperature and thermal stability, suggesting a great potential for applications.

  7. Preparation and properties of nanophase (Ce, Zr, Pr)O{sub 2}-doped alumina coating on cordierite ceramic honeycomb for three-way catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Jiuying; Lu, Jusheng [School of Chemistry and Chemical Engineering, Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Xuzhou Normal University, Xuzhou P.R. (China)

    2012-01-15

    Nanophase (Ce, Zr, Pr)O{sub 2}-doped alumina coatings were prepared by impregnating the cordierite ceramic honeycomb in the sol or in the slurry of already calcined powder, respectively. The effects of preparation methods on the crystal phase, texture, oxygen storage capacity (OSC), reducibility, surface morphology and thermal stability of coatings were investigated by X-ray diffraction (XRD), the Brunauer Emmet Teller (BET) method, the oxygen pulsing technique, H2-temperature-programmed reduction (H2-TPR) and scanning electron microscopy (SEM). These nanophase (Ce, Zr, Pr)O{sub 2}-doped alumina coatings were used as supports to prepare Pd-only three-way catalysts, and evaluated with respect to catalytic activities. The results indicate that the nanophase (Ce, Zr, Pr)O{sub 2}-doped alumina coatings prepared by the two methods have high thermal stability. However, the coating derived from the sol shows better crystalline structure, texture, reducibility and oxygen storage capacity than the coating derived from the slurry. SEM observation shows that the morphology of the coating derived from the sol is uniform and smooth. The Pd-only catalyst derived from the sol exhibits high three-way catalytic activity at low temperature and thermal stability, suggesting a great potential for applications. (author)

  8. Preparation of recyclable Pd(Ⅱ organometal catalyst with bicontinuous cubic Ia3d mesostructure for water-medium organic reaction

    Directory of Open Access Journals (Sweden)

    YANG Didi

    2012-12-01

    Full Text Available A heterogenous Pd(Ⅱ organometal catalyst with bicontinuous cubic Ia3d mesostructure was synthesized by surfactant-directed co-condensation of Pd[PPh2(CH22Si(OCH2CH33]2Cl2 and (CH3CH2O3SiPhSi(OCH2CH33.In water-medium Sonogashira reaction,the as-prepared Pd(Ⅱ-PMO-KIT-6 exhibited higher catalytic activity than reference catalyst Pd(Ⅱ-KIT-6 and could be used repetitively for more than 4 times,which could reduce the cost and even diminish the environmental pollution from heavy metallic ions,showing a good potential in industrial applications.

  9. Ni-loaded nanocrystalline ceria-zirconia solid solutions prepared via modified Pechini route as stable to coking catalysts of CH4 dry reforming

    Directory of Open Access Journals (Sweden)

    Sadykov Vladislav A.

    2016-01-01

    Full Text Available Mixed nanocrystalline Ce-Zr-O oxides (Ce/Zr = 1 or 7/3 were prepared by modified Pechini route using ethylene glycol solutions of metal salts. Detailed characterization of their real structure and surface properties by X-ray diffraction on synchrotron radiation with the full-profile Rietveld analysis, high resolution electron microscopy with elemental analysis, Raman spectroscopy, UV-Vis and X-ray photoelectron spectroscopy revealed a high homogeneity of cations distribution in nanodomains resulting in stabilization of disordered cubic phase. This provides a high dispersion of NiO loaded on these mixed oxides by wet impregnation, a high reactivity and mobility of oxygen in these catalysts and strong interaction of Ni with support in the reduced state. This helps to achieve a high activity and coking stability of developed catalysts in CH4 dry reforming in feeds with CH4 concentration up to 15% and CH4/CO2 ratio =1.

  10. A novel Ce(IO3)4 catalyst: Facile preparation and high activity in degradation of organic dyes without light irradiation at room temperature

    Science.gov (United States)

    Li, Jiayin; Ma, Xinping; Zhao, Caixian; Lan, Fujun; Chen, Feng; Liu, Xuan; Tang, Jianting

    2017-01-01

    Developing efficient catalysts capable of degrading organic dye free of light irradiation is highly interesting from the energy-saving point of view. In this work, we prepared a new Ce(IO3)4 catalyst by a facile precipitation method. The obtained Ce(IO3)4 sample showed remarkably superior performance to the reported CeGeO4 analog in degradation of rhodamine B (RhB), methyl orange (MO) or methylene blue (MB) dyes in the dark at room temperature. The ultraviolet-visible (UV-vis) absorption spectra of dye solution during degradation, the XPS results of Ce(IO3)4 and the control experiments confirmed that the dye degradation is a catalytic process. The reusability of it was also investigated in the degradation experiments.

  11. Experimental study on a low-temperature SCR catalyst based on MnO(x)/TiO(2) prepared by sol-gel method.

    Science.gov (United States)

    Wu, Zhongbiao; Jiang, Boqiong; Liu, Yue; Zhao, Weirong; Guan, Baohong

    2007-07-16

    A catalyst based on MnO(x)/TiO(2) was prepared by sol-gel method for low-temperature selective catalytic reduction (SCR) of NO with NH(3). Focusing on the effects of the operating parameters, the SCR reaction was investigated at temperatures from 353 to 523K under steady and transient states. Under the optimal conditions, the efficiency of NO removal could exceed 90% at temperature of 423K. Furthermore, within the range investigated, the reaction order of NO, NH(3), O(2) was determined to be 1, 0, and 0.5, respectively. Apparent activation energy was also calculated to be 38kJ/mol, lower than that for most of the catalysts reported by previous investigations.

  12. Preparation and application of acidified/calcined red mud catalyst for catalytic degradation of butyl xanthate in Fenton-like process.

    Science.gov (United States)

    Shao, Luhua; Wei, Guangtao; Wang, Yizhi; Li, Zhongmin; Zhang, Linye; Zhao, Shukai; Zhou, Ming

    2016-08-01

    Acidified/calcined red mud (ACRM), a novel catalyst used in Fenton-like process, was prepared by acidification and calcination of red mud (RM). Catalyst characterization showed that iron phase of ACRM was mainly α-Fe2O3 and ACRM was a porous material with rough surface and loose structure. Degradation of butyl xanthate in Fenton-like process catalyzed by ACRM was investigated. Butyl xanthate was effectively degraded, and the degradation of butyl xanthate was well fitted by second order kinetic model. ACRM had an excellent long-term stability in a Fenton-like process. The possible mechanisms of hydroxyl radical production and butyl xanthate degradation in a Fenton-like process catalyzed by ACRM were presented.

  13. Study of Pd-Sn/Al{sub 2}O{sub 3} catalysts prepared by an oxide colloidal route; Etude de catalyseurs Pd-Sn/Al{sub 2}O{sub 3} prepares par voie colloidale oxyde

    Energy Technology Data Exchange (ETDEWEB)

    Verdier, St.

    2001-09-01

    The oxide colloidal route, developed in the laboratory for mono-metallic catalysts, consists in preparing a metallic oxide hydro-sol which leads to the supported catalyst after deposition onto a support and an activation stage. In this work, this method has been adapted to the preparation of alumina supported bimetallic Pd-Sn catalysts to determine its interest for the control of the properties of the bimetallic phase (size, composition and structure). In the preliminary study concerning tin oxide sols, SnO{sub 2} (size=2,3 nm) and Sn{sub 6}O{sub 4}(OH){sub 4} (size = 25 nm) nano-particles were synthesized by neutralization respectively for tin(IV) and tin(H). The control through the pH of the aggregation of the PdO and SnO{sub 2} particles revealed that increasing oxide solubility promotes integral re-dispersion of the oxide particles. To synthesize oxide bimetallic sols, three strategies were defined. Copolymerization (formation of a mixed oxide nano-sol by cross condensation of both metals) does not lead to a mixed oxide Pd-Sn phase. Surface precipitation (neutralization of the second metal in the presence of the first oxide sol) yields nano-particles of both oxides in close interaction. Adsorption (adsorption of the second metal onto the first oxide sol) significantly occurs when contacting tin with a basic PdO sol (hydrolytic adsorption). The characterization and the assessment of the catalytic properties (selective hydrogenation of buta-1,3-diene) of the catalysts prepared by deposition of oxide bimetallic sols showed that the oxide colloidal route allows the control of the properties of the supported bimetallic phase. Moreover, our results display that both Pd-Sn alloy formation and,aggregation of the metallic particles contribute to increase the selectivity for this reaction. (author)

  14. Preparation of manganese oxide immobilized on SBA-15 by atomic layer deposition as an efficient and reusable catalyst for selective oxidation of benzyl alcohol in the liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Mahdavi, Vahid, E-mail: v-mahdavi@araku.ac.ir; Mardani, Mahdieh

    2015-04-01

    Manganese oxide supported on mesoporous silica SBA-15 catalyst (Mn-SBA-15) was tested with Mn contents in the range of 0.8–23 wt%. Samples were prepared by the controlled grafting process of atomic layer deposition (ALD). Other sample was prepared for comparisons by the wet impregnation method. These samples were characterized by the techniques of ICP, XRD, SEM, Raman, FT-IR spectroscopy, diffuse reflectance UV–Vis, TGA-DSC, and N{sub 2} absorption–desorption surface area measurement. Results indicated that anchored manganese oxide particles have been successfully synthesized over the surface of SBA-15. These samples contained Red-Ox ion pairs of Mn{sup 2+} and Mn{sup 3+} highly dispersed on the mesoporous silica surface. The impregnated sample exhibited lower surface area and contained Red-Ox ion pairs of Mn{sup 3+} and Mn{sup 4+} more aggregated particles on the SBA-15 surface. Results determined Mn-SBA-15 as an efficient and selective catalyst for oxidation of benzyl alcohol with tert-butylhydroperoxide in liquid phase. In accordance with expectations, there was a negligible amount of leaching of immobilized manganese oxide from the support during the reaction, because of strong surface interaction between manganese oxide and hydroxyls groups. The influences of reaction temperature, reaction time, solvent, TBHP/benzyl alcohol molar ratio, amount of catalyst and reusability were investigated. Under optimized conditions (0.2 g catalyst, TBHP/benzyl alcohol molar ratio 1, solvent acetonitrile; T = 90 °C; reaction time 8 h), results achieved 70% conversion of benzyl alcohol and 100% selectivity to benzaldehyde. - Highlights: • Manganese oxide immobilized on SBA-15 were prepared by atomic layer deposition (ALD). • Oxidation of benzyl alcohol to benzaldehyde over this catalyst were investigated. • Effects of loading of manganese oxide, T, oxidant/alcohol ratio were investigated. • The leaching of manganese oxide from support during the reaction was

  15. VO x /SiO 2 Catalyst Prepared by Grafting VOCl 3 on Silica for Oxidative Dehydrogenation of Propane

    KAUST Repository

    Zhu, Haibo

    2015-09-07

    The VOx/SiO2 catalysts for oxidative dehydrogenation of propane were synthesized by a simple grafting method. The VOCl3 was first grafted at the surface of SiO2, which was dehydrated at different temperature (from 200 to 1000°C). The formed grafted complexes were then calcined in air, leading to the formation of VOx/SiO2 catalysts. The synthesized catalysts were characterized by nitrogen adsorption, SEM, Raman spectroscopy, temperature-programmed reduction, and extended X-ray absorption fine structure analysis. The SiO2 pretreatment temperature has an evident effect on the loading and dispersion of VOx on SiO2, which finally affects their catalytic performance. High SiO2 treatment temperature is beneficial to dispersing the vanadium oxide species at the SiO2 surface. These materials are efficient catalysts for the catalytic oxidative dehydrogenation of propane to propylene. The best selectivity to propylene is achieved on the VOx/SiO2-(1000) catalyst. The high selectivity and activity are well maintained for three days catalytic reaction. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Certain aspects of the formation and identification of nanosized oxide components in heterogeneous catalysts prepared by different methods

    Energy Technology Data Exchange (ETDEWEB)

    Ellert, Ol' ga G; Novotortsev, Vladimir M [N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Tsodikov, Mark V [A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow (Russian Federation)

    2010-10-19

    The results of studies into the relationship 'methods and synthesis conditions of a catalyst{yields}catalyst structure{yields}catalytic properties' in highly efficient crystallo-graphically amorphous copper- and iron-containing heterogeneous systems obtained by different chemical methods are generalized. Polymorphism of active phases and catalytic properties of nanostructured copper-containing zinc, zirconium, manganese and cerium oxides are discussed. Unusual transformations of nanosized Pt- and Pd-containing components on the {gamma}-Al{sub 2}O{sub 3} surface in nanostructured catalysts of ethanol steam reforming into synthesis gas and reductive dehydration of ethanol to alkanes are considered. The results of comparative studies on the crystallographically amorphous mixed iron oxide catalysts synthesized by either the alkoxy method or the deposition on various supports obtained by the Moessbauer and XAFS spectroscopy and magnetic susceptibility measurements are presented. These materials are shown to be efficient catalysts of important processes such as liquid-phase oxidation of hydrocarbons, synthesis of alkenes and alkylaromatic hydrocarbons from CO and H{sub 2}, hydrogenative transformation of brown coal organic mass to hydrocarbons.

  17. Crumpled rGO-supported Pt-Ir bifunctional catalyst prepared by spray pyrolysis for unitized regenerative fuel cells

    Science.gov (United States)

    Kim, In Gyeom; Nah, In Wook; Oh, In-Hwan; Park, Sehkyu

    2017-10-01

    Three-dimensional (3D) crumpled reduced graphene oxide supported Pt-Ir alloys that served as bifunctional oxygen catalysts for use in untized regenerative fuel cells were synthesized by a facile spray pyrolysis method. Pt-Ir catalysts supported on rGO (Pt-Ir/rGOs) were physically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) to observe change in composition by heat treatment, alloying, and morphological transition of the catalysts. Their catalytic activities and stabilities for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) conditions were electrochemically investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), potential cycling and hold tests on the rotating disk electrode (RDE). Pt-Ir/rGO with no post heat-treatment (Pt-Ir/rGO_NP) showed a lower activity for ORR and OER although metal nanoparticles decorated on the support are relatively small. However, Pt-Ir/rGO showed remarkably enhanced activity following heat treatment, depending on temperature. Pt-Ir/rGO heat-treated at 600 °C after spray pyrolysis (Pt-Ir/rGO_P600) exhibited a higher activity and stability than a commercially available Pt/C catalyst kept under the ORR condition, and it also revealed a comparable OER activity and durability versus the commercial unsupported Ir catalyst.

  18. Pulse electrodeposition to prepare core-shell structured AuPt@Pd/C catalyst for formic acid fuel cell application

    Science.gov (United States)

    Lu, Xueyi; Luo, Fan; Song, Huiyu; Liao, Shijun; Li, Hualing

    2014-01-01

    A novel core-shell structured AuPt@Pd/C catalyst for the electrooxidation of formic acid is synthesized by a pulse electrodeposition process, and the AuPt core nanoparticles are obtained by a NaBH4 reduction method. The catalyst is characterized with X-ray powder diffraction and transmission electron microscopy, thermogravimetric analysis, cyclic voltammetry, CO stripping and X-ray photoelectron spectroscopy. The core-shell structure of the catalyst is revealed by the increase in particle size resulting from a Pd layer covering the AuPt core, and by a negative shift in the CO stripping peaks. The addition of a small amount of Pt improves the dispersion of Au and results in smaller core particles. The catalyst's activity is evaluated by cyclic voltammetry in formic acid solution. The catalyst shows excellent activity towards the anodic oxidation of formic acid, the mass activity reaches 4.4 A mg-1Pd and 0.83 A mg-1metal, which are 8.5 and 1.6 times that of commercial Pd/C. This enhanced electrocatalytic activity could be ascribed to the good dispersion of Au core particles resulting from the addition of Pt, as well as to the interaction between the Pd shell layer and the Au and Pt in the core nanoparticles.

  19. Characterization of Pd catalyst-electrodes deposited on YSZ: Influence of the preparation technique and the presence of a ceria interlayer

    Science.gov (United States)

    Jiménez-Borja, Carmen; Matei, Florina; Dorado, Fernando; Valverde, José Luis

    2012-11-01

    Palladium catalyst-electrodes supported on Y2O3-stabilized-ZrO2 (YSZ) prepared either by paste deposition or wet impregnation technique were characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found a strong dependence of the catalytic film preparation technique as well as of the presence of a ceria interlayer between the palladium film and the solid electrolyte on the catalytic activity towards methane oxidation. Impregnated palladium films were found to be more active than films prepared by paste deposition. Besides, the addition of ceria allowed stabilizing the palladium active phase for methane oxidation.

  20. Production of Gasoline and Diesel from Biomass via Fast Pyrolysis, Hydrotreating and Hydrocracking: A Design Case

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Susanne B.; Valkenburt, Corinne; Walton, Christie W.; Elliott, Douglas C.; Holladay, Johnathan E.; Stevens, Don J.; Kinchin, Christopher; Czernik, Stefan

    2009-02-25

    The purpose of this study is to evaluate a processing pathway for converting biomass into infrastructure-compatible hydrocarbon biofuels. This design case investigates production of fast pyrolysis oil from biomass and the upgrading of that bio-oil as a means for generating infrastructure-ready renewable gasoline and diesel fuels. This study has been conducted using similar methodology and underlying basis assumptions as the previous design cases for ethanol. The overall concept and specific processing steps were selected because significant data on this approach exists in the public literature. The analysis evaluates technology that has been demonstrated at the laboratory scale or is in early stages of commercialization. The fast pyrolysis of biomass is already at an early stage of commercialization, while upgrading bio-oil to transportation fuels has only been demonstrated in the laboratory and at small engineering development scale. Advanced methods of pyrolysis, which are under development, are not evaluated in this study. These may be the subject of subsequent analysis by OBP. The plant is designed to use 2000 dry metric tons/day of hybrid poplar wood chips to produce 76 million gallons/year of gasoline and diesel. The processing steps include: 1.Feed drying and size reduction 2.Fast pyrolysis to a highly oxygenated liquid product 3.Hydrotreating of the fast pyrolysis oil to a stable hydrocarbon oil with less than 2% oxygen 4.Hydrocracking of the heavy portion of the stable hydrocarbon oil 5.Distillation of the hydrotreated and hydrocracked oil into gasoline and diesel fuel blendstocks 6. Hydrogen production to support the hydrotreater reactors. The "as received" feedstock to the pyrolysis plant will be "reactor ready". This development will likely further decrease the cost of producing the fuel. An important sensitivity is the possibility of co-locating the plant with an existing refinery. In this case, the plant consists only of the first three steps: feed

  1. Production of Gasoline and Diesel from Biomass via Fast Pyrolysis, Hydrotreating and Hydrocracking: A Design Case

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Susanne B.; Valkenburt, Corinne; Walton, Christie W.; Elliott, Douglas C.; Holladay, Johnathan E.; Stevens, Don J.; Kinchin, Christopher; Czernik, Stefan

    2009-02-28

    The purpose of this study is to evaluate a processing pathway for converting biomass into infrastructure-compatible hydrocarbon biofuels. This design case investigates production of fast pyrolysis oil from biomass and the upgrading of that bio-oil as a means for generating infrastructure-ready renewable gasoline and diesel fuels. This study has been conducted using the same methodology and underlying basis assumptions as the previous design cases for ethanol. The overall concept and specific processing steps were selected because significant data on this approach exists in the public literature. The analysis evaluates technology that has been demonstrated at the laboratory scale or is in early stages of commercialization. The fast pyrolysis of biomass is already at an early stage of commercialization, while upgrading bio-oil to transportation fuels has only been demonstrated in the laboratory and at small engineering development scale. Advanced methods of pyrolysis, which are under development, are not evaluated in this study. These may be the subject of subsequent analysis by OBP. The plant is designed to use 2000 dry metric tons/day of hybrid poplar wood chips to produce 76 million gallons/year of gasoline and diesel. The processing steps include: 1.Feed drying and size reduction 2.Fast pyrolysis to a highly oxygenated liquid product 3.Hydrotreating of the fast pyrolysis oil to a stable hydrocarbon oil with less than 2% oxygen 4.Hydrocracking of the heavy portion of the stable hydrocarbon oil 5.Distillation of the hydrotreated and hydrocracked oil into gasoline and diesel fuel blendstocks 6. Hydrogen production to support the hydrotreater reactors. The “as received” feedstock to the pyrolysis plant will be “reactor ready.” This development will likely further decrease the cost of producing the fuel. An important sensitivity is the possibility of co-locating the plant with an existing refinery. In this case, the plant consists only of the first three steps

  2. Production of Gasoline and Diesel from Biomass via Fast Pyrolysis, Hydrotreating and Hydrocracking: A Design Case

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Susanne B.; Valkenburt, Corinne; Walton, Christie W.; Elliott, Douglas C.; Holladay, Johnathan E.; Stevens, Don J.; Kinchin, Christopher; Czernik, Stefan

    2009-02-28

    The purpose of this study is to evaluate a processing pathway for converting biomass into infrastructure-compatible hydrocarbon biofuels. This design case investigates production of fast pyrolysis oil from biomass and the upgrading of that bio-oil as a means for generating infrastructure-ready renewable gasoline and diesel fuels. This study has been conducted using the same methodology and underlying basis assumptions as the previous design cases for ethanol. The overall concept and specific processing steps were selected because significant data on this approach exists in the public literature. The analysis evaluates technology that has been demonstrated at the laboratory scale or is in early stages of commercialization. The fast pyrolysis of biomass is already at an early stage of commercialization, while upgrading bio-oil to transportation fuels has only been demonstrated in the laboratory and at small engineering development scale. Advanced methods of pyrolysis, which are under development, are not evaluated in this study. These may be the subject of subsequent analysis by OBP. The plant is designed to use 2000 dry metric tons/day of hybrid poplar wood chips to produce 76 million gallons/year of gasoline and diesel. The processing steps include: 1.Feed drying and size reduction 2.Fast pyrolysis to a highly oxygenated liquid product 3.Hydrotreating of the fast pyrolysis oil to a stable hydrocarbon oil with less than 2% oxygen 4.Hydrocracking of the heavy portion of the stable hydrocarbon oil 5.Distillation of the hydrotreated and hydrocracked oil into gasoline and diesel fuel blendstocks 6. Hydrogen production to support the hydrotreater reactors. The “as received” feedstock to the pyrolysis plant will be “reactor ready.” This development will likely further decrease the cost of producing the fuel. An important sensitivity is the possibility of co-locating the plant with an existing refinery. In this case, the plant consists only of the first three steps

  3. Production of Gasoline and Diesel from Biomass via Fast Pyrolysis, Hydrotreating and Hydrocracking: A Design Case

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Susanne B.; Valkenburt, Corinne; Walton, Christie W.; Elliott, Douglas C.; Holladay, Johnathan E.; Stevens, Don J.; Kinchin, Christopher; Czernik, Stefan

    2009-02-25

    The purpose of this study is to evaluate a processing pathway for converting biomass into infrastructure-compatible hydrocarbon biofuels. This design case investigates production of fast pyrolysis oil from biomass and the upgrading of that bio-oil as a means for generating infrastructure-ready renewable gasoline and diesel fuels. This study has been conducted using similar methodology and underlying basis assumptions as the previous design cases for ethanol. The overall concept and specific processing steps were selected because significant data on this approach exists in the public literature. The analysis evaluates technology that has been demonstrated at the laboratory scale or is in early stages of commercialization. The fast pyrolysis of biomass is already at an early stage of commercialization, while upgrading bio-oil to transportation fuels has only been demonstrated in the laboratory and at small engineering development scale. Advanced methods of pyrolysis, which are under development, are not evaluated in this study. These may be the subject of subsequent analysis by OBP. The plant is designed to use 2000 dry metric tons/day of hybrid poplar wood chips to produce 76 million gallons/year of gasoline and diesel. The processing steps include: 1.Feed drying and size reduction 2.Fast pyrolysis to a highly oxygenated liquid product 3.Hydrotreating of the fast pyrolysis oil to a stable hydrocarbon oil with less than 2% oxygen 4.Hydrocracking of the heavy portion of the stable hydrocarbon oil 5.Distillation of the hydrotreated and hydrocracked oil into gasoline and diesel fuel blendstocks 6. Hydrogen production to support the hydrotreater reactors. The "as received" feedstock to the pyrolysis plant will be "reactor ready". This development will likely further decrease the cost of producing the fuel. An important sensitivity is the possibility of co-locating the plant with an existing refinery. In this case, the plant consists only of the first three steps: feed

  4. Catalytic Combustion of Low Concentration Methane over Catalysts Prepared from Co/Mg-Mn Layered Double Hydroxides

    Directory of Open Access Journals (Sweden)

    Hongfeng Liu

    2014-01-01

    Full Text Available A series of Co/Mg-Mn mixed oxides were synthesized through thermal decomposition of layered double hydroxides (LDHs precursors. The resulted catalysts were then subjected for catalytic combustion of methane. Experimental results revealed that the Co4.5Mg1.5Mn2LDO catalyst possessed the best performance with the T90=485°C. After being analyzed via XRD, BET-BJH, SEM, H2-TPR, and XPS techniques, it was observed that the addition of cobalt had significantly improved the redox ability of the catalysts whilst certain amount of magnesium was essential to guarantee the catalytic activity. The presence of Mg was helpful to enhance the oxygen mobility and, meanwhile, improved the dispersion of Co and Mn oxides, preventing the surface area loss after calcination.

  5. A comparative study of CeO2-Al2O3 support prepared with different methods and its application on MoO3/CeO2-Al2O3 catalyst for sulfur-resistant methanation

    Science.gov (United States)

    Jiang, Minhong; Wang, Baowei; Yao, Yuqin; Li, Zhenhua; Ma, Xinbin; Qin, Shaodong; Sun, Qi

    2013-11-01

    The CeO2-Al2O3 supports prepared with impregnation (IM), deposition precipitation (DP), and solution combustion (SC) methods for MoO3/CeO2-Al2O3 catalyst were investigated in the sulfur-resistant methanation. The supports and catalysts were characterized by N2-physisorption, transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy (RS), and temperature-programmed reduction (TPR). The N2-physisorption results indicated that the DP method was favorable for obtaining better textural properties. The TEM and RS results suggested that there is a CeO2 layer on the surface of the support prepared with DP method. This CeO2 layer not only prevented the interaction between MoO3 and γ-Al2O3 to form Al2(MoO4)3 species, but also improved the dispersion of MoO3 in the catalyst. Accordingly, the catalysts whose supports were prepared with DP method exhibited the best catalytic activity. The catalysts whose supports were prepared with SC method had the worst catalytic activity. This was caused by the formation of Al2(MoO4)3 and crystalline MoO3. Additionally, the CeO2 layer resulted in the instability of catalysts in reaction process. The increasing of calcination temperature of supports reduced the catalytic activity of all catalysts. The decrease extent of the catalysts whose supports were prepared with DP method was the lowest as the CeO2 layer prevented the interaction between MoO3 and γ-Al2O3.

  6. Study on Preparation of Isosorbitol Using Solid acid Catalyst%固体酸催化合成异山梨醇的研究

    Institute of Scientific and Technical Information of China (English)

    张跃华

    2012-01-01

    To prepare isosorbitol by dehydration reaction of sorbitol with p-toluenesulfonic acid as the catalyst, tolu- ene as dehydrating agent. The product quality reached Japanese standards, the yield was 50%.%以对甲苯磺酸为催化剂、甲苯为带水剂,山梨醇脱水制备异山梨醇,产品质量符合日本药典XV质量标准,收率约为50%。

  7. Simple cerium-triethanolamine complex: Synthesis, characterization, thermal decomposition and its application to prepare ceria support for platinum catalysts used in methane steam reforming

    Science.gov (United States)

    Wattanathana, Worawat; Nootsuwan, Nollapan; Veranitisagul, Chatchai; Koonsaeng, Nattamon; Laosiripojana, Navadol; Laobuthee, Apirat

    2015-06-01

    Cerium-triethanolamine complex was synthesized by simple complexation method in 1-propanol solvent using cerium(III) chloride as a metal source and triethanolamine as a ligand. The structures of the prepared complex were proposed based on FT-IR, FT-Raman and ESI-MS results as equimolar of triethanolamine and cerium chelated complex having monomeric tricyclic structure with and without chloride anion as another coordinating group known as ceratrane. The complex was used as a precursor for ceria material done by thermal decomposition. XRD result revealed that when calcined at 600 °C for 2 h, the cerium complex was totally turned into pure ceria with cubic fluorite structure. The obtained ceria was then employed to synthesize platinum doped ceria catalysts for methane steam reforming. Various amounts of platinum i.e. 1, 3, 5 and 10 mol percents were introduced on the ceria support by microwave-assisted wetness impregnation using ammonium tetrachloroplatinate(II). The platinum-impregnated ceria powders were subjected to calcination in 10% hydrogen/helium atmosphere at 500 °C for 3 h to reduce platinum(II) to platinum(0). XRD patterns of the catalysts confirmed that the platinum particles doped on the ceria support were in the form of platinum(0). Catalytic activity test showed that the catalytic activities got higher as the amounts of platinum doped increased. Besides, the portions of coke formation on the surface of catalysts were reduced as the amounts of platinum doped increased.

  8. Butanol Dehydration over V2O5-TiO2/MCM-41 Catalysts Prepared via Liquid Phase Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Jong-Ki Jeon

    2013-04-01

    Full Text Available MCM-41 was used as a support and, by using atomic layer deposition (ALD in the liquid phase, a catalyst was prepared by consecutively loading titanium oxide and vanadium oxide to the support. This research analyzes the effect of the loading amount of vanadium oxide on the acidic characteristics and catalytic performance in the dehydration of butanol. The physical and chemical characteristics of the TiO2-V2O5/MCM-41 catalysts were analyzed using XRF, BET, NH3-TPD, XRD, Py-IR, and XPS. The dehydration reaction of butanol was performed in a fixed bed reactor. For the samples with vanadium oxide loaded to TiO2/MCM-41 sample using the liquid phase ALD method, it was possible to increase the loading amount until the amount of vanadium oxide reached 12.1 wt %. It was confirmed that the structural properties of the mesoporous silica were retained well after titanium oxide and vanadium loading. The NH3-TPD and Py-IR results indicated that weak acid sites were produced over the TiO2/MCM-41 samples, which is attributed to the generation of Lewis acid sites. The highest activity of the V2O5(12.1-TiO2/MCM-41 catalyst in 2-butanol dehydration is ascribed to it having the highest number of Lewis acid sites, as well as the highest vanadium dispersion.

  9. In-situ characterization of heterogeneous catalysts

    CERN Document Server

    Rodriguez, Jose A; Chupas, Peter J

    2013-01-01

    Helps researchers develop new catalysts for sustainable fuel and chemical production Reviewing the latest developments in the field, this book explores the in-situ characterization of heterogeneous catalysts, enabling readers to take full advantage of the sophisticated techniques used to study heterogeneous catalysts and reaction mechanisms. In using these techniques, readers can learn to improve the selectivity and the performance of catalysts and how to prepare catalysts as efficiently as possible, with minimum waste. In-situ Characterization of Heterogeneous Catalysts feat

  10. Preparation of N-doped ZnO-loaded halloysite nanotubes catalysts with high solar-light photocatalytic activity.

    Science.gov (United States)

    Cheng, Zhi-Lin; Sun, Wei

    2015-01-01

    N-doped ZnO nanoparticles were successfully assembled into hollow halloysite nanotubes (HNTs) by using the impregnation method. The catalysts based on N-doped ZnO-loaded HNTs nanocomposites (N-doped ZnO/HNTs) were characterized by X-ray diffraction (XRD), transmission electron microscopy-energy dispersive X-ray (TEM-EDX), scanning electron microscopy-energy dispersive X-ray (SEM-EDX), UV-vis and Fourier transform infrared spectroscopy (FT-IR) techniques. The XRD pattern showed ZnO nanoparticles with hexagonal structure loaded on HNTs. The TEM-EDX analysis indicated ZnO particles with the crystal size of ca.10 nm scattered in hollow structure of HNTs, and furthermore the concentration of N atom in nanocomposites was up to 2.31%. The SEM-EDX verified most of N-ZnO nanoparticles existing in hollow nanotubes of HNTs. Besides containing an obvious ultraviolet absorbance band, the UV-vis spectra of the N-doped ZnO/HNTs catalysts showed an available visible absorbance band by comparing to HNTs and non-doped ZnO/HNTs. The photocatalytic activity of the N-doped ZnO/HNTs catalysts was evaluated by the degradation of methyl orange (MO) solution with the concentration of 20 mg/L under the simulated solar-light irradiation. The result showed that the N-doped ZnO/HNTs catalyst exhibited a desirable solar-light photocatalytic activity.

  11. Selective preparation of zeolite X and A from flyash and its use as catalyst for biodiesel production.

    Science.gov (United States)

    Volli, Vikranth; Purkait, M K

    2015-10-30

    This work discusses the utilization of flyash for synthesis of heterogeneous catalyst for transesterification. Different types of zeolites were synthesized from alkali fusion followed by hydrothermal treatment of coal flyash as source material. The synthesis conditions were optimized to obtain highly crystalline zeolite based on degree of crystallinity and cation exchange capacity (CEC). The effect of CEC, acid treatment, Si/Al ratio and calcination temperature (800, 900 and 1000 °C) on zeolite formation was also studied. Pure, single phase and highly crystalline zeolite was obtained at flyash/NaOH ratio (1:1.2), fusion temperature (550 °C), fusion time (1 h), hydrothermal temperature (110 °C) and hydrothermal time (12h). The synthesized zeolite was ion-exchanged with potassium and was used as catalyst for transesterification of mustard oil to obtain a maximum conversion of 84.6% with 5 wt% catalyst concentration, 12:1 methanol to oil molar ratio, reaction time of 7 h at 65 °C. The catalyst was reused for 3 times with marginal reduction in activity.

  12. Certain aspects of the formation and identification of nanosized oxide components in heterogeneous catalysts prepared by different methods

    Science.gov (United States)

    Ellert, Ol'ga G.; Tsodikov, Mark V.; Novotortsev, Vladimir M.

    2010-10-01

    The results of studies into the relationship 'methods and synthesis conditions of a catalyst→catalyst structure→catalytic properties' in highly efficient crystallo-graphically amorphous copper- and iron-containing heterogeneous systems obtained by different chemical methods are generalized. Polymorphism of active phases and catalytic properties of nanostructured copper-containing zinc, zirconium, manganese and cerium oxides are discussed. Unusual transformations of nanosized Pt- and Pd-containing components on the γ-Al2O3 surface in nanostructured catalysts of ethanol steam reforming into synthesis gas and reductive dehydration of ethanol to alkanes are considered. The results of comparative studies on the crystallographically amorphous mixed iron oxide catalysts synthesized by either the alkoxy method or the deposition on various supports obtained by the Mössbauer and XAFS spectroscopy and magnetic susceptibility measurements are presented. These materials are shown to be efficient catalysts of important processes such as liquid-phase oxidation of hydrocarbons, synthesis of alkenes and alkylaromatic hydrocarbons from CO and H2, hydrogenative transformation of brown coal organic mass to hydrocarbons.

  13. Effect of the preparation method of support on the aqueous phase reforming of ethylene glycol over 2 wt% Pt/Ce0.15Zr0.85O2 catalysts.

    Science.gov (United States)

    Kim, Jung-Hyun; Jeong, Kwang-Eun; Kim, Tae-Wan; Chae, Ho-Jeong; Jeong, Soon-Yong; Kim, Chul-Ung; Lee, Kwan-Young

    2013-08-01

    The effect of catalyst support on the aqueous phase reforming of ethylene glycol over supported 2 wt% Pt/Ce0.15Zr0.85O2 catalysts have been investigated. Various types of Ce0.15Zr0.85O2 mixed oxides were prepared by hydrothermal precipitation (CZH), modified precipitation (CZM), co-precipitation (CZC), sol-gel (CZS) methods, respectively. Catalysts were characterized by XRD, N2 sorption analysis, and cyclohexane dehydration for relative metal dispersion. The support effect on the activity of 2 wt% Pt/Ce0.15Zr0.85O2 catalysts with different preparation method was given as follows: CZH production rate and hydrogen yield increased in proportion to the reaction temperature and corresponding system pressure, whereas WHSV did not affect.

  14. Oxidation catalyst

    Science.gov (United States)

    Ceyer, Sylvia T.; Lahr, David L.

    2010-11-09

    The present invention generally relates to catalyst systems and methods for oxidation of carbon monoxide. The invention involves catalyst compositions which may be advantageously altered by, for example, modification of the catalyst surface to enhance catalyst performance. Catalyst systems of the present invention may be capable of performing the oxidation of carbon monoxide at relatively lower temperatures (e.g., 200 K and below) and at relatively higher reaction rates than known catalysts. Additionally, catalyst systems disclosed herein may be substantially lower in cost than current commercial catalysts. Such catalyst systems may be useful in, for example, catalytic converters, fuel cells, sensors, and the like.

  15. Preparation of Pt-Re/Vulcan carbon nanocomposites using a single-source molecular precursor and relative performance as a direct methanol fuel cell electrooxidation catalyst.

    Science.gov (United States)

    Anderson, Angela D; Deluga, Gregg A; Moore, Joshua T; Vergne, Matthew J; Hercules, David M; Kenik, Edward A; Lukehart, C M

    2004-09-01

    Pt-Re/Vulcan carbon powder nanocomposites have been prepared with total metal loadings of 18 wt.% and 40 wt.% using a new non-cluster (1:1)-PtRe bimetallic precursor as the source of metal. Pt-Re nanoparticles having an average diameter of ca. 6 nm and atomic stoichiometry near 1:1 are formed. TEM, on-particle HR-EDS, and powder XRD data are consistent with the formation of Pt-Re alloy nanoparticles having a hexagonal unit cell with cell constants of a = 2.77 A and c = 4.47 A. A nanocomposite prepared at higher total metal loading under more rigorous thermal treatment also contains Pt-Re alloy nanoparticles having a fcc unit cell structure (a = 3.95 A). The precise dependence of Pt-Re nanocrystal structure on the thermal history of the nanocomposite specimen has not been investigated in detail. While these Pt-Re/carbon nanocomposites are active as anode catalysts in operating direct methanol fuel cells, the measured performance is less than that of commercial Pt-Ru/carbon catalysts and has marginal practical importance.

  16. Innovative Route to Prepare of Au/C Catalysts by Replication of Gold-containing Mesoporous Silicas

    KAUST Repository

    Kerdi, Fatmé

    2011-12-23

    Gold-catalyzed aerobic epoxidations in the liquid phase are generally performed in low-polarity solvents, in which conventional oxide-supported catalysts are poorly dispersed. To improve the wettability of the catalytic powder and, thus, the efficiency of the catalyst, gold nanoparticles (NPs) have been dispersed on meso-structured carbons. Gold is first introduced in functionalized mesostructured silica and particles are formed inside the porosity. Silica pores are then impregnated with a carbon precursor and the composite material is heated at 900 °C under vacuum or nitrogen. Silica is then removed by acid leaching, leading to partially encapsulated gold particles in mesoporous carbon. Carbon prevents aggregation of gold particles at high temperature, both the mean size and distribution being similar to those observed in silica. However, while Au@SiO2 exhibit significant catalytic activity in the aerobic oxidation of trans-stilbene in the liquid phase, its Au@C mesostructured replica is quite inactive.

  17. Innovative Route to Prepare of Au/C Catalysts by Replication of Gold-containing Mesoporous Silicas

    Science.gov (United States)

    Kerdi, Fatmé; Caps, Valérie; Tuel, Alain

    Gold-catalyzed aerobic epoxidations in the liquid phase are generally performed in low-polarity solvents, in which conventional oxide-supported catalysts are poorly dispersed. To improve the wettability of the catalytic powder and, thus, the efficiency of the catalyst, gold nanoparticles (NPs) have been dispersed on meso-structured carbons. Gold is first introduced in functionalized mesostructured silica and particles are formed inside the porosity. Silica pores are then impregnated with a carbon precursor and the composite material is heated at 900 °C under vacuum or nitrogen. Silica is then removed by acid leaching, leading to partially encapsulated gold particles in mesoporous carbon. Carbon prevents aggregation of gold particles at high temperature, both the mean size and distribution being similar to those observed in silica. However, while Au@SiO2 exhibit significant catalytic activity in the aerobic oxidation of trans-stilbene in the liquid phase, its Au@C mesostructured replica is quite inactive.

  18. Aqueous-Phase Preparation of Model HDS Catalysts on Planar Alumina Substrates: Support Effect on Mo Adsorption and Sulfidation.

    Science.gov (United States)

    Bara, Cédric; Plais, Lucie; Larmier, Kim; Devers, Elodie; Digne, Mathieu; Lamic-Humblot, Anne-Félicie; Pirngruber, Gerhard D; Carrier, Xavier

    2015-12-23

    The role of the oxide support on the structure of the MoS2 active phase (size, morphology, orientation, sulfidation ratio, etc.) remains an open question in hydrotreating catalysis and biomass processing with important industrial implications for the design of improved catalytic formulations. The present work builds on an aqueous-phase surface-science approach using four well-defined α-alumina single crystal surfaces (C (0001), A (112̅0), M (101̅0), and R (11̅02) planes) as surrogates for γ-alumina (the industrial support) in order to discriminate the specific role of individual support facets. The reactivity of the various surface orientations toward molybdenum adsorption is controlled by the speciation of surface hydroxyls that determines the surface charge at the oxide/water interface. The C (0001) plane is inert, and the R (11̅02) plane has a limited Mo adsorption capacity while the A (112̅0) and M (101̅0) surfaces are highly reactive. Sulfidation of model catalysts reveals the highest sulfidation degree for the A (112̅0) and M (101̅0) planes suggesting weak metal/support interactions. Conversely, a low sulfidation rate and shorter MoS2 slabs are found for the R (11̅02) plane implying stronger Mo-O-Al bonds. These limiting cases are reminiscent of type I/type II MoS2 nanostructures. Structural analogies between α- and γ- alumina surfaces allow us to bridge the material gap with real Al2O3-supported catalysts. Hence, it can be proposed that Mo distribution and sulfidation rate are heterogeneous and surface-dependent on industrial γ-Al2O3-supported high-surface-area catalysts. These results demonstrate that a proper control of the γ-alumina morphology is a strategic lever for a molecular-scale design of hydrotreating catalysts.

  19. 直接涂膜技术用于质子交换膜燃料电池膜电极制备%MEA PREPARATION FOR POLYMER ELECTROLYTE MEMBRANE FUEL CELL BY APPLYING DIRECTLY PRINTING CATALYST ON MEMBRANE TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    蒋淇忠; 马紫峰; Oumarou Savadogo

    2004-01-01

    A new membrane electrolyte assembly (MEA) preparation method for polymer electrolyte membrane fuel cell (PEMFC) was developed by applying the directly printing catalyst on membrane technique. This method was simple and easy to be controlled as verified by repetition experiment. When the membrane with catalyst prepared by the new technique and the electrode with diffusion layer was only sandwiched but not hot pressed, this kind of MEA was called not-hot-press MEA (NPMEA) and its fuel cell performance was better than that of MEA which was hot pressed (HPMEA). The effects of 6 different kinds of solvents in catalyst mixture ink on the performance of fuel cell were assessed. It was discovered that iso-propanol was the best solvent in catalyst mixture ink and showed the best performance of fuel cell. Finally several MEAs prepared by different ways were tested on fuel cell station and it was reported that the performance of MEA prepared by the directly printing catalyst on membrane technique was the best in the whole voltage region.

  20. Characterization of Pd catalyst-electrodes deposited on YSZ: Influence of the preparation technique and the presence of a ceria interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Borja, Carmen, E-mail: Carmen.JBorja@uclm.es [Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad de Castilla-La Mancha. Avenida Camilo Jose Cela 12, 13071 Ciudad Real (Spain); Matei, Florina [Department of Petroleum Processing Engineering and Environmental Protection, Petroleum - Gas University of Ploiesti (Romania); Dorado, Fernando; Valverde, Jose Luis [Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad de Castilla-La Mancha. Avenida Camilo Jose Cela 12, 13071 Ciudad Real (Spain)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Impregnation of palladium over YSZ led to more dispersed films. Black-Right-Pointing-Pointer XPS spectra indicated electron deficient Pd{sup 2+} species on the surface of palladium films. Black-Right-Pointing-Pointer Impregnated palladium films were more active than those prepared by paste deposition Black-Right-Pointing-Pointer The addition of a CeO{sub 2} interlayer enhanced the catalytic rate for the impregnated samples. - Abstract: Palladium catalyst-electrodes supported on Y{sub 2}O{sub 3}-stabilized-ZrO{sub 2} (YSZ) prepared either by paste deposition or wet impregnation technique were characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found a strong dependence of the catalytic film preparation technique as well as of the presence of a ceria interlayer between the palladium film and the solid electrolyte on the catalytic activity towards methane oxidation. Impregnated palladium films were found to be more active than films prepared by paste deposition. Besides, the addition of ceria allowed stabilizing the palladium active phase for methane oxidation.

  1. Catalyst preactivation using EURECAT TOTSUCAT CFP technology

    Energy Technology Data Exchange (ETDEWEB)

    Brahma, N.; Alexander, R.; Robinson, J. [Eurecat US Inc., Houston, TX (United States)

    2009-07-01

    This presentation described EURECAT's newly developed and patented technology that allows the start up of a hydrotreating process without the introduction of sulphur containing chemicals. This ex-situ process known as TOTSUCAT ensures complete activation and sulphiding of the catalyst prior to loading in the reactor. The benefits of TOTSUCAT include the elimination of sour water formation; the prevention of potential exotherms; minimal hydrogen sulphide (H{sub 2}) pressure; and no need for additional hydrogen. TOTSUCAT can be used in cases where the unit has temperature limitations that prevent a complete activation of the catalyst. The TOTSUCAT cracked feed protection (CFP) is an enhanced treatment that combines the advantages of preactivation with the ability to start up a unit with cracked stocks. It eliminates the need to delay the introduction of cracked feeds for 3 to 5 days after start-up, as is typical in commercial hydroprocessing units. The acidity of the catalyst is reduced in the CFP treatment, making it suitable for early introduction of cracked stocks. As such, the technology has potential use in the field of residual hydrocracking. The technology has been successfully applied in several commercial refineries in North America. tabs., figs.

  2. Green and efficient sample preparation method for the determination of catalyst residues in margarine by ICP-MS.

    Science.gov (United States)

    Hartwig, Carla Andrade; Pereira, Rodrigo Mendes; Novo, Diogo La Rosa; Oliveira, Dirce Taina Teixeira; Mesko, Marcia Foster

    2017-11-01

    Responding to the need for green and efficient methods to determine catalyst residues with suitable precision and accuracy in samples with high fat content, the present work evaluates a microwave-assisted ultraviolet digestion (MW-UV) system for margarines and subsequent determination of Ni, Pd and Pt using inductively coupled plasma mass spectrometry (ICP-MS). It was possible to digest up to 500mg of margarine using only 10mL of 4molL(-1) HNO3 with a digestion efficiency higher than 98%. This allowed the determination of catalyst residues using the ICP-MS and free of interferences. For this purpose, the following experimental parameters were evaluated: concentration of digestion solution, sample mass and microwave irradiation program. The residual carbon content was used as a parameter to evaluate the efficiency of digestion and to select the most suitable experimental conditions. The accuracy evaluation was performed by recovery tests using a standard solution and certified reference material, and recoveries ranging from 94% to 99% were obtained for all analytes. The limits of detection for Ni, Pd and Pt using the proposed method were 35.6, 0.264 and 0.302ngg(-1), respectively. When compared to microwave-assisted digestion (MW-AD) in closed vessels using concentrated HNO3 (used as a reference method for sample digestion), the proposed MW-UV could be considered an excellent alternative for the digestion of margarine, as this method requires only a diluted nitric acid solution for efficient digestion. In addition, MW-UV provides appropriate solutions for further ICP-MS determination with suitable precision (relative standard deviation < 7%) and accuracy for all evaluated analytes. The proposed method was applied to margarines from different brands produced in Brazil, and the concentration of catalyst residues was in agreement with the current legislation or recommendations. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. 碳化镍钼催化剂的制备及其甲烷干气重整活性%Preparation of a Nickel Molybdenum Carbide Catalyst and Its Activity in the Dry Reforming of Methane

    Institute of Scientific and Technical Information of China (English)

    Taro HIROSE; Yasushi OZAWA; Masatoshi NAGAI

    2011-01-01

    Nickel molybdenum carbide catalysts were prepared and their activities in the CO2 reforming of methane at a low CO2/CH4 reactant ratio were investigated using a microreactor at atmospheric pressure and at 973 K The effect of the catalyst preparation method and the Ni/Mo ratio on the increase in catalyst life and the promotion of catalytic activity were investigated using N2 adsorption, X-ray diffraction,temperature-programmed carburization, temperature-programmed reaction, and a reforming reaction. The 25Ni75Mo catalyst that was carburized at 813 K exhibited the highest hydrogen fonnation ability and gave the least carbon deposition. The incomplete carburization of the Mo oxide species in the catalyst that was carburized at a lower temperature gradually gave a more active carburized species. The NiMoOxCy in the catalyst was more active in hydrogen formation during the dry reforming of methane while β-Mo2C and η-Mo3C2 were less active.

  4. Preparation and characterization of La0.8Cu0.2MnO(3±δ) perovskite-type catalyst for methane combustion

    Institute of Scientific and Technical Information of China (English)

    HE Fang; WANG Hua; DAI Yong-nian

    2005-01-01

    La0.8 Cu0.2 MnO(3±δ) perovskite-type catalyst for methane combustion prepared through sol-gel process was characterized by X-ray Diffractometry(XRD), X-ray Photoelectron Spectroscopy(XPS) and Scanning Electron Microscopy(SEM). XPS analyses reveal that the surface characteristics of the catalyst are changed. The lattice defects and oxygen vacancies on the catalyst surface are enhanced due to a part of La3+ being substituted by Cu2+.Temperature-programmed-desorption(TPD) and temperature-programmed-reduction(TPR) analyses were carried out to study the catalytic behavior. It is found that there are two O2-desorption peaks at 350 ℃ and 650 ℃ in the TPD pattern, and two CH4-consumption peaks at 420 ℃ and 750 ℃ in the TPR patterns respectively, which indicates that the two kinds of oxygen species, so-called α and β oxygen, can react with the methane during catalytic combustion process. The catalytic activity tests were performed in a fixed-bed reactor, and the results show that the T1/2 at which the conversion of methane attains 50 % of La0.8 Cu0.2 MnO(3±δ) is lower by 55 ℃ than that of LaMnO3.This indicates that the catalytic activity of La0.8 Cu0. 2 MnO(3±δ) is increased with partial substitution of Cu2+ for La3+.

  5. Preparation of Cyclic Urethanes from Amino Alcohols and Carbon Dioxide Using Ionic Liquid Catalysts with Alkali Metal Promoters

    Directory of Open Access Journals (Sweden)

    Masahiko Arai

    2006-10-01

    Full Text Available Several ionic liquids were applied as catalysts for the synthesis of cyclicurethanes from amino alcohols and pressurized CO2 in the presence of alkali metalcompounds as promoters. A comparative study was made for the catalytic performanceusing different ionic liquids, substrates, promoters, and pressures. The optimum catalyticsystem was BMIM-Br promoted by K2CO3, which, for 1-amino-2-propanol, produced cyclicurethane in 40% yield with a smaller yield of substituted cyclic urea and no oligomericbyproducts. For other amino alcohols, cyclic urethanes, cyclic ureas, and/or undesiredbyproducts were produced in different yields depending on the substrates used. Possiblereaction mechanisms are proposed.

  6. Hydrocarbon conversion process and catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, A.; Huizinga, T.; Maxwell, I.E.

    1989-08-15

    This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.40 A, a water adsorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of between 10% and 15% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; am amorphous cracking component, a binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

  7. Characterization and performance of Cu/ZnO/Al2O3 catalysts prepared via decomposition of M(Cu,Zn)-ammonia complexes under sub-atmospheric pressure for methanol synthesis from H2 and CO2

    Institute of Scientific and Technical Information of China (English)

    Danjun Wang; Jun Zhao; Huanling Song; Lingjun Chou

    2011-01-01

    Methanol synthesis from hydrogenation of CO2 is investigated over Cu/ZnO/Al2O3 catalysts prepared by decomposition of M(Cu,Zn)-ammonia complexes (DMAC) at various temperatures.The catalysts were characterized in detail,including X-ray diffraction,N2 adsorption-desorption,N2O chemisorption,temperature-programmed reduction and evolved gas analyses.The influences of DMAC temperature,reaction temperature and specific Cu surface area on catalytic performance are investigated.It is considered that the aurichalcite phase in the precursor plays a key role in improving the physiochemical properties and activities of the final catalysts.The catalyst from rich-aurichalcite precursor exhibits large specific Cu surface area and high space time yield of methanol (212 g/(Lcat·h); T =513 K,p =3 MPa,S V =12000 h-1).

  8. Influence of catalyst on structural and morphological properties of TiO2 nanostructured films prepared by sol-gel on glass

    Institute of Scientific and Technical Information of China (English)

    Mehdi Alzamani; Ali Shokuhfar; Ebrahim Eghdam; Sadegh Mastali

    2013-01-01

    Transparent TiO2 thin films have been prepared by the sol-gel method using titanium alkoxides as precursors. Thin films were deposited on glass supports by the dip-coating technique. The TiO2 layer acts as a self-cleaning coating generated from its photocatalysis and photoinduced superhydrophilicity. The crystalline structure of TiO2 films was dominantly identified as the anatase phase, consisted of uniform spherical particles of about 14-50 nm in size, which strongly depends upon catalyst-type and heat treatment temperature. Increasing heat treating temperature can lead to an increase in crystalline size. The results indicated that the sample S.S (sample derived from sol containing sulfuric acid as catalyst) exhibits superhydrophilic nature and better photocatalytic activity, which can be attributed to its higher anatase content and lower crystalline size. Morphological studies, carried out using Atomic Force Microscopy (AFM), confirm the presence of crystalline phase with such a grain size and low surface roughness. Thus, the applied films exhibiting high photocatalytic activity, superhydrophilic behavior, and low surface roughness can be used as an efficient self-cleaning coating on glass and other optical applications.

  9. Fast preparation of PtRu catalysts supported on carbon nanofibers by the microwave-polyol method and their application to fuel cells.

    Science.gov (United States)

    Tsuji, Masaharu; Kubokawa, Masatoshi; Yano, Ryuto; Miyamae, Nobuhiro; Tsuji, Takeshi; Jun, Mun-Suk; Hong, Seonghwa; Lim, Seongyop; Yoon, Seong-Ho; Mochida, Isao

    2007-01-16

    PtRu alloy nanoparticles (24 +/- 1 wt %, Ru/Pt atomic ratios = 0.91-0.97) supported on carbon nanofibers (CNFs) were prepared within a few minutes by using a microwave-polyol method. Three types of CNFs with very different surface structures, such as platelet, herringbone, and tubular ones, were used as new carbon supports. The dependence of particles sizes and electrochemical properties on the structures of CNFs was examined. It was found that the methanol fuel cell activities of PtRu/CNF catalysts were in the order of platelet > tubular > herringbone. The methanol fuel cell activities of PtRu/CNFs measured at 60 degrees C were 1.7-3.0 times higher than that of a standard PtRu (29 wt %, Ru/Pt atomic ratio = 0.92) catalyst loaded on carbon black (Vulcan XC72R) support. The best electrocatalytic activity was obtained for the platelet CNF, which is characterized by its edge surface and high graphitization degree.

  10. Preparation and activity evaluation of NiMoB/γ-Al2O3 catalyst by liquid-phase furfural hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Shuqin Wei; Hongyou Cui; Jinghua Wang; Shuping Zhuo; Weiming Yi; Lihong Wang; Zhihe Li

    2011-01-01

    Amorphous MoNiB/γ-Al2O3 alloy catalysts were prepared by reducing NiCl2-6H2O and genation of furfural (FFR) as a probe reaction,the activity of MoNiB/γ-Al2O3 was examined. Compared to NiB and NiMoB,NiMoB/γ-Al2O3 exhibited excellent activity and selectivity towards furfuryl alcohol (FFA). After reaction for 3.0 h at 80 °C and 5.0 MPa in methanol,FFR conversion reached 99% with FFA yield of 91%. The effects of doping amount of Mo and calcination temperature before NaBH4 reduction on hydrogenation activity were also investigated. The optimum Mo/Ni atom ratio and calcination temperature were found to be 1:7 and 300 C,respectively. XRD patterns and SEM images indicated that NiMoB over the surface of γ-Al2O3 was amorphous and highly dispersed,which was responsible for the high thermal stability of the title catalyst.

  11. Preparation of Fe-Mn/K/Al2O3 Fischer-Tropsch Catalyst and Its Catalytic Kinetics for the Hydrogenation of Carbon Monoxide

    Institute of Scientific and Technical Information of China (English)

    F.Fazlollahi; M.Sarkari; H.Gharebaghi; H.Atashi; M.M.Zarei; A.A.Mirzaei; W.C.Hecker

    2013-01-01

    A K promoted iron-manganese catalyst was prepared by sol-gel method,and subsequently was tested for hydrogenation of carbon monoxide to light olefins.The kinetic experiments on a well-characterized Fe-Mn/K/Al2O3 catalyst were performed in a fixed-bed micro-reactor in a temperature range of 280-380 ℃,pressure range of 0.1-1.2 MPa,H2/CO feed molar ratio range of 1-2.1 and a space velocity range of 2000-7200 h-1.Considering the mechanism of the process and Langmuir-Hinshelwood-Hogan-Watson (LHHW) approach,unassisted CO dissociation and H-assisted CO dissociation mechanisms were defined.The best models were obtained using non-linear regression analysis and Levenberg-Marquardt algorithm.Consequently,4 models were considered as the preferred models based on the carbide mechanism.Finally,a model was proposed as a best model that assumed the following kinetically relevant steps in the iron-Fischer-Tropsch (FT) synthesis:(1) CO dissociation occurred without hydrogen interaction and was not a rate-limiting step; (2) the first hydrogen addition to surface carbon was the rate-determining steps.The activation energy and adsorption enthalpy were calculated 40.0 and-30.2 kJ· mol-1,respectively.

  12. Preparative treatment with NaOH to selectively concentrate iron oxides of a Chilean volcanic soil material to produce effective heterogeneous Fenton catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Manzo, Valentina; Pizarro, Carmen, E-mail: carmen.pizarro@usach.cl; Rubio, Maria Angelica [USACH, Facultad de Quimica y Biologia (Chile); Cavalcante, Luis Carlos Duarte [UFMG, Departamento de Quimica-ICEx (Brazil); Garg, Vijayendra Kumar [Universidade de Brasilia, Instituto de Fisica (Brazil); Fabris, Jose Domingos [UFMG, Departamento de Quimica-ICEx (Brazil)

    2011-11-15

    A Chilean volcanic Ultisol material was first size-fractionated so as to obtain the fraction with mean particle sizes {phi} < 53 {mu}m. This sample was then sequentially treated three or five times with 5 mol L{sup - 1} NaOH, in an attempt to evaluate the effectiveness of the selective chemical dissolution to concentrate iron oxides, as a preparation procedure before using the materials as heterogeneous Fenton catalysts. The effects of those treatments on the iron oxides mineralogy were monitored with Moessbauer spectroscopy. The NaOH-treated samples were tested as catalysts towards the H{sub 2}O{sub 2} decomposition. Three or five sequential NaOH treatments were found to be comparably effective, by concentrating nearly the same proportion of iron oxides in the remaining solid phase (25.1 {+-} 0.4 and 23.3 {+-} 0.2 mass%, respectively). 298 K-Moessbauer patterns were similar for both samples, with a central (super)paramagnetic Fe{sup 3 + } doublet and a broad sextet, assignable to several closely coexisting magnetically ordered forms of iron oxides. Despite of this nearly similar effect of the two treatments, the Ultisol material treated three times with NaOH presents higher heterogeneous catalytic efficiency and is more suitable to decompose H{sub 2}O{sub 2} than that with five treatments.

  13. A study of Cu/ZnO/Al2O3 methanol catalysts prepared by flame combustion synthesis

    DEFF Research Database (Denmark)

    Jensen, Joakim Reimer; Johannessen, Tue; Wedel, Stig;

    2003-01-01

    The flame combustion synthesis of Cu/ZnO/Al2O3 catalysts for the synthesis of methanol from CO, CO2 and H2 is investigated. The oxides are generated in a premixed flame from the acetyl-acetonate vapours of Cu, Zn and Al mixed with the fuel and air prior to combustion. The flame-generated powder...... is examined by X-ray powder diffraction, determination of the specific surface area by the BET-method, determination of the copper dispersion in the reduced catalyst by a novel N2O-method, by transmission electron microscopy, and by test of the catalytic properties in a catalytic micro-reactor. A low peak...... temperature and quench-cooling of the flame tend to increase the dispersion of the phases and the specific surface area of the particles. Properties of both the ternary composition, the three binary compositions and the pure oxides are discussed. The calculation of simultaneous phase and chemical equilibrium...

  14. Low temperature SCR of NO with catalysts prepared by modified ACF loading Mn and Ce: effects of modification method.

    Science.gov (United States)

    Li, Ping; Lu, Pei; Zhai, Yunbo; Li, Caiting; Chen, Ting; Qing, Renpeng; Zhang, Wei

    2015-01-01

    Achievement of a higher NOx conversion ratio in selective catalytic reduction (SCR) at low temperature is challenging. In this work, pure activated carbon fibres (ACFs) were modified with different ratios of H2O (g), NaOH, CO2 and HNO3, respectively (named as modified ACF). The chemical and physical properties of modified ACFs were identified by Brunauer-Emmett-Teller, X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy methods. The NOx conversion ratio of ACF was improved from 56.1% to 82.4% at 80°C after modification with 30% (mass ratio) NaOH. These modified ACFs were further loaded with the mixture of MnO2 and CeO2 in the form of metal salt solutions (named as Mn0.5Ce0.5O2/modified ACF). The NOx conversion ratio of 30% SHACF remained similar at 80°C but was increased from 60.0% to 98.5% at 360°C after loading with Mn and Ce, which showed the best performance in SCR of NOx at low temperature. It could be seen that ACF delivered higher performance in low temperature SCR after being modified with the aforementioned reactants and further loading with metals. Based on chemical and physical characterization and the performance of the catalysts, the reasons for different performances of these catalysts in low temperature SCR are discussed.

  15. Methane reforming With CO2 to syngas over CeO2-promoted Ni/Al2O3-ZrO2 catalysts Prepared Via a direct sol-gel process

    Institute of Scientific and Technical Information of China (English)

    Hansheng Li; Hang Xu; Jinfu Wang

    2011-01-01

    CeO2-promoted Ni/Al2O3-ZrO2 (Ni/Al2O3-ZrO2-CeO2) catalysts were prepared by a direct sol-gel process with citric acid as gelling agent.The catalysts used for the methane reforming with CO2 was studied by infrared spectroscopy (IR), thermal gravimetric analysis (TGA), microscopic analysis, X-ray diffraction (XRD) and temperature-programmed reduction (TPR).The catalytic performance for CO2 reforming of methane to synthesis gas was investigated in a continuous-flow micro-reactor under atmospheric pressure.TGA, IR, XRD and microscopic analysis show that the catalysts prepared by the direct sol-gel process consist of Ni particles with a nanostructure of around 5 nm and an amorphous-phase composite oxide support.There exists a chemical interaction between metallic Ni particles and supports, which makes metallic Ni well dispersed, highly active and stable.The addition of CeO2 effectively improves the dispersion and the stability of Ni particles of the prepared catalysts, and enhances the adsorption of CO2 on the surface of catalysts.The catalytic tests for methane reforming with CO2 to synthesis gas show that the Ni/Al2O3-ZrO2-CeO2 catalysts show excellent activity and stability compared with the Ni/Al2O3 catalyst.The excellent catalytic activity and stability of the Ni/Al2O3-ZrO2-CeO2 are attributed to the highly, uniformly and stably dispersed small metallic Ni particles, the high reducibility of the Ni oxides and the interaction between metallic Ni particles and the composite oxide supports.

  16. On the Effect of Preparation Methods of PdCe-MOR Catalysts as NOx CH4-SCR System for Natural Gas Vehicles Application

    Directory of Open Access Journals (Sweden)

    Acácio Nobre Mendes

    2015-10-01

    Full Text Available In the present work, the effect of several parameters involved in the preparation of PdCe-HMOR catalysts active for NOx selective catalytic reduction with methane (NOx CH4-SCR was studied. Results show that the catalytic performance of Pd-HMOR is better when palladium is introduced by ion-exchange, namely at room temperature. It was also shown that Pd loading does not influence the formation of cerium species, namely surface Ce4+ (CeO2 species and CeO2 species in interaction with Pd. However, when Ce is introduced before Pd, more surface CeO2 species are stabilized in the support and less CeO2 become in interaction with Pd, which results in a worse NOx CH4-SCR catalytic performance.

  17. Synthesis of Ni/Mg/Al Layered Double Hydroxides and Their Use as Catalyst Precursors in the Preparation of Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yun; JIAO Qing-ze; LIANG Ji; LI Chun-hua

    2005-01-01

    Ni/Mg/Al layered double hydroxides(LDHs) with different n(Ni):n(Mg):n(Al) ratio values were prepared via a coprecipitation reaction. Then Ni/Mg/Al mixed oxides were obtained by calcination of these LDHs precursors. Carbon nanotubes were produced in the catalytic decomposition of propane over the Ni/Mg/Al mixed oxide catalysts. The quality of as-made nanotubes was investigated by SEM and TEM. The nanotubes were multiwall with a high length-diameter ratio and appeared to be flexible. The catalytic activities of these mixed oxides increased with increasing the Ni content. The Ni/Mg/Al mixed oxide with the highest Ni content [n(Ni)/n(Mg)/n(Al)=1/1/1] showed the highest activity and the carbon nanotubes grown on its surface had the best quality.

  18. Phase Composition of Ni/Mg1−xNixO as a Catalyst Prepared for Selective Methanation of CO in H2-Rich Gas

    OpenAIRE

    Mengmeng Zhang; Hongwei Ma; Zhiming Gao

    2015-01-01

    Supported Ni catalysts Ni/Mg1−xNixO were prepared by reducing samples NiO-MgO in H2/N2 mixture gas at 500°C~800°C for selective methanation of CO in H2-rich gas (CO-SMET). The samples NiO-MgO were obtained by heating water slurry of MgO and Ni(NO3)2 in a rotary evaporator at 80°C and a final calcination in air at 400°C~800°C. X-ray diffraction (XRD) and temperature programmed reduction (TPR) measurements demonstrate that the samples NiO-MgO were composed of solid solution Mg1−yNiyO as the mai...

  19. Air-cathode preparation with activated carbon as catalyst, PTFE as binder and nickel foam as current collector for microbial fuel cells.

    Science.gov (United States)

    Cheng, Shaoan; Wu, Jiancheng

    2013-08-01

    A cathode is a critical factor that limits the practical application of microbial fuel cells (MFCs) in terms of cost and power generation. To develop a cost-effective cathode, we investigate a cathode preparation technique using nickel foam as a current collector, activated carbon as a catalyst and PTFE as a binder. The effects of the type and loading of conductive carbon, the type and loading of activated carbon, and PTFE loading on cathode performance are systematically studied by linear sweep voltammetry (LSV). The nickel foam cathode MFC produces a power density of 1190±50 mW m(-2), comparable with 1320 mW m(-2) from a typical carbon cloth Pt cathode MFC. However, the cost of a nickel foam activated carbon cathode is 1/30 of that of carbon cloth Pt cathode. The results indicate that a nickel foam cathode could be used in scaling up the MFC system.

  20. Preparation of nickel ferrite/carbon nanotubes composite by microwave irradiation technique for use as catalyst in photo-fenton reaction

    Energy Technology Data Exchange (ETDEWEB)

    Foletto, E.L.; Rigo, C.; Severo, E.C.; Mazutti, M.A.; Dotto, G.L.; Jahn, S.L.; Sales, J.C. [Universidade Federal de Santa Maria (UFSM), RS (Brazil); Chiavone-Filho, O. [Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil); Gundel, A.; Lucchese, M. [Universidade Federal do Pampa (UNIPAMPA), Bage, RS (Brazil)

    2016-07-01

    Full text: Nickel ferrite/multi-walled carbon nanotubes (NiFe2O4/MWCNTs) composite has been rapidly synthesized via microwave irradiation technique. The structural properties of the formed product was investigated by X-ray diffraction (XRD), N2 adsorption/desorption isotherms, thermogravimetric analysis (TGA), Raman spectroscopy and, scanning electron microscopy (SEM). The catalytic behavior of composite material was evaluated by the degradation of Amaranth dye in the photo-Fenton reaction under visible light irradiation. The overall results showed that the prepared composite was successfully synthesized, demonstrating good performance in the dye degradation, with higher degradation rate compared to the NiFe2O4. The high efficiency in dye degradation can be attributed to synergism between NiFe2O4 and MWCNTs. Therefore, NiFe2O4/MWCNTs composite can be used as promising photo-Fenton catalyst to degrade Amaranth dye from aqueous solutions. (author)

  1. Preparation of Nano-Sized γ-Al2O3 Supported Iron Catalyst for Fischer-Tropsch Synthesis by Solvated Metal Atom Impregnation Methods

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Two types of small iron clusters supported on γ-Al2O3-RT(dehydroxylated at room temperature) and γ-Al2O3-800 (dehydroxylated at 800 ℃) were prepared by solvated metal atom impregnation (SMAI) techniques. The iron atom precursor complex, bis(toluene)iron(0) formed in the metal atom reactor, was impregnated into γ-Al2O3 having different concentrations of surface hydroxyl groups to study the effect of surface hydroxylation on the crucial stage of iron cluster formation. Catalysts prepared in this way were characterized by TEM, M(o)ssbauer, and chemisorption measurements, and the results show that higher concentration of surface hydroxyl groups of γ-Al2O3-RT favors the formation of more positively charged supported iron cluster Fen/γ-Al2O3-RT, and the lower concentration of surface hydroxyl groups of γ-Al2O3-800 favors the formation of basically neutral supported iron cluster Fen/γ-Al2O3-800. The measured results also indicate that the higher concentration of surface hydroxyl groups causes the rapid decomposition of precursor complex, bis(toluene)iron(0), and favors the formation of relatively large iron cluster. Consequently, these two types of catalysts show different catalytic properties in Fischer-Tropsch reaction. The catalytic pattern of Fen/γ-Al2O3-RT in F-T reaction is similar to that of the unreduced α-Fe2O3 and that of Fen/γ-Al2O3-800 is similar to that of the reduced α-Fe2O3.

  2. Preparation of nanosize Cu-ZnO/Al{sub 2}O{sub 3} catalyst for methanol synthesis by phase transfer with metal surfactant. 2: Effect of additives and chain length of surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Z.; Chen, S.; Peng, S. [Chinese Academy of Science, Taiyuan, Shanxi (China). Inst. of Coal Chemistry

    1996-09-25

    Nanosize Cu-ZnO/Al{sub 2}O{sub 3} catalysts for methanol synthesis were prepared by the metal surfactant phase transfer technique. The effects of chain length of surfactant and additives were studied. It was found that the longer the organic chain of surfactant, the more stable the sol particles and the larger the surface area of catalyst. The decomposition temperature of surfactants with longer chains was also higher. For the preparation of Cu-ZnO/Al{sub 2}O{sub 3} catalyst, the surfactant organic chain should not be longer than 11 carbon atoms. A synergist could be used to improve surfactant efficiency. A stabilizing agent was used to strength the stability of sol particles in water. The time needed for oil-water separation was reduced markedly by using a demulsifying agent. The optimal mole ratios of synergist, stabilizing agent, and demulsifying agent to surfactant were, respectively, 0.6, 0.6, and 1.

  3. Novel bimetallic dispersed catalysts for temperature-programmed coal liquefaction. Quarterly technical progress report, July--September 1995

    Energy Technology Data Exchange (ETDEWEB)

    Song, Chunshan; Schmidt, E.; Schobert, H.H.

    1996-01-01

    Coal liquefaction involves cleavage of methylene, dimethylene and ether bridges connecting polycyclic aromatic units and the reactions of various oxygen functional groups. Here in this quarterly, we report on the hydrocracking of 4-(l-naphthylmethyl)bibenzyl in the presence of iron (Fe) catalysts and sulfur and residual wall catalytic effect. Catalytic hydrocracking of 4-(1-naphthylmethyl)bibenzyl (NMBB) predominantly yielded naphthalene and 4-methylbibenzyl. Various iron compounds were examined as catalyst precursors. Sulfur addition to most catalyst precursors led to substantially higher catalyst activity and higher conversion. NMBB was also treated with sulfur in the absence of iron compounds, in concentrations of 1.2-3.4 wt%, corresponding to the conditions present in reactions with added iron compounds. Increasing sulfur concentrations led to higher NMBB conversions. Furthermore, sulfur had a permanent effect on the reactor walls. A black sulfide layer formed on the surface which could not be removed mechanically. The supposed non-catalytic reactions done in the same reactor but after experiments with added sulfur showed higher conversions than comparable experiments done in new reactors. This wall catalytic effect can be reduced by treating the sulfided reactors with hydrochloric acid. The results of this work demonstrate the significant effect of sulfur addition and sulfur-induced residual wall effects on carbon-carbon bond cleavage and hydrogenation of aromatics.

  4. Supported -pyrrolidine-2-carboxylic acid-4-hydrogen sulphate on silica gel as an economical and efficient catalyst for the one-pot preparation of -acetamido ketones via a four-component condensation reaction

    Indian Academy of Sciences (India)

    Arash Ghorbani-Choghamarani; Parisa Zamani

    2014-01-01

    An efficient, one-pot, four-component condensation of aldehydes, acetophenone (or propiophenone), acetyl chloride and acetonitrile in the presence of catalytic amounts of -pyrrolidine-2-carboxylic acid-4-hydrogen sulphate (supported on silica gel), a green and non-toxic catalyst, is described for the preparation of -acetamido ketones in good to excellent yields.

  5. On the Interaction between Co- and Mo-complexes in impregnation solutions used for the preparation of Al2O3-supported HDS catalysts: a combined Raman/UV-Vis-NIR spectroscopy study

    NARCIS (Netherlands)

    Bergwerff, J.A.; Visser, T.; Weckhuysen, B.M.

    2008-01-01

    Research has been carried out on the formation of cobalt (Co) and molybdenum (Mo) complexes in CoMo-solutions, which are used for the preparation of Al2O3-supported hydrodesulphurization (HDS) catalysts. Aim of this study was to obtain more insight into possible Co–Mo interactions and their implicat

  6. Effect of operating conditions and potassium content on Fischer-Tropsch liquid products produced by potassium-promoted iron catalysts

    Institute of Scientific and Technical Information of China (English)

    Francisco E. M. Farias; Fernando G. Sales; Fabiano A. N. Fernandes

    2008-01-01

    The dependencies of Fischer-Tropsch synthesis liquid hydrocarbon product distribution on operating pressure and temperature have been studied over three potassium-promoted iron catalysts with increasing potassium molar content. The study followed an experimental planning and the results were analyzed based on surface response methodology. The effects of different operating conditions and potassium contents on the liquid product distribution were compared based on number average carbon number and dispersion. Results showed that high pressures (25 to 30 atm) favored the production of waxes that could be converted into liquid fuels through hydrocracking, while greater direct selectivity towards diesel was favored by low pressure (20 atm) using catalysts with low potassium to iron molar ratios. The liquid product distribution produced using an iron catalyst with high potassium content presented higher number-average number of carbons when compared to the distribution obtained using an iron catalyst with low potassium content.

  7. Influence of preparation on the catalytic performances of zirconia based catalysts for high temperature N{sub 2}O decomposition; Influence des conditions de preparation sur les performances de catalyseurs a base de zircone pour la decomposition du N{sub 2}O a tres haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Esteves, Ph.; Granger, P.; Leclercq, L.; Leclercq, G.; Payen, E. [Universite des Sciences et technologies de Lille, 59 - Villeneuve d' Ascq (France); Kieger, St. [Grande Paroisse S.A., Usine de Rouen, 76 - Grand Quevilly (France); Navascues, L. [Grande Paroisse S.A., 92 - Paris la Defense (France)

    2001-07-01

    Various preparation procedures of zirconia based catalysts modified by additives and their catalytic properties in the decomposition of N{sub 2}O at high temperature have been investigated. The most relevant observation was for ZrO{sub 2} containing 1% of additive with a synergy effect in comparison with a reference ZrO{sub 2} catalyst. For higher additive contents such a synergy effect disappears. (authors)

  8. Surface properties of palladium catalysts supported on ternary ZrO2-Al2O3-WOx oxides prepared by the sol-gel method: Study of the chemical state of the support

    Science.gov (United States)

    Barrera, A.; Montoya, J. A.; del Angel, P.; Navarrete, J.; Cano, M. E.; Tzompantzi, F.; López-Gaona, A.

    2012-08-01

    The surface properties of Pd and Pd-Pt catalysts supported on binary ZrO2-WOx and ternary ZrO2-Al2O3-WOx oxides prepared by the sol-gel method were studied. Special attention was paid to the study of the texture of the catalysts as well as the chemical state of tungstated zirconia and tungstated zirconia promoted with alumina in the palladium catalysts. The catalysts were tested in the isomerization of n-hexane and were characterized by N2 physisorption, XRD, TPR, Raman spectroscopy, XPS and FT-IR of adsorbed pyridine. The catalysts had bimodal pore size distributions with mesopores in the range 55-70 Å and macropores of 1000 Å in diameter. The catalysts had a surface WOx coverage (4.4-6.0 W nm-2) lower than that of the theoretical monolayer (7.0 W nm-2). A lower acidity of the ternary ZrO2-Al2O3-WOx oxide as compared to the binary ZrO2-WOx oxide was found. Higher activity in the isomerisation of n-hexane was obtained in the Pd-Pt catalysts supported on ternary ZrAlW oxides prepared by sol-gel that is correlated with the coexistence on the surface of W4+ (WO2) or W0 and W6+ (Al2(WO4)3) species, ZrO2 in the tetragonal phase and a high amount of ZrOx suboxides species in a low oxidation state (Zr3+ and Zr2+).

  9. Study of Supported Nickel Catalysts Prepared by Aqueous Hydrazine Method. Hydrogenating Properties and Hydrogen Storage: Support Effect. Silver Additive Effect; Catalyseurs de nickel supportes prepares par la methode de l'hydrazine aqueuse. Proprietes hydrogenantes et stockage d'hydrogene. Effet du support. Effet de l'ajout d'argent

    Energy Technology Data Exchange (ETDEWEB)

    Wojcieszak, R

    2006-06-15

    We have studied Ni or NiAg nano-particles obtained by the reduction of nickel salts (acetate or nitrate) by hydrazine and deposited by simple or EDTA-double impregnation on various supports ({gamma}-Al{sub 2}O{sub 3}, amorphous or crystallized SiO{sub 2}, Nb{sub 2}O{sub 5}, CeO{sub 2} and carbon). Prepared catalysts were characterized by different methods (XRD, XPS, low temperature adsorption and desorption of N{sub 2}, FTIR and FTIR-Pyridine, TEM, STEM, EDS, H{sub 2}-TPR, H{sub 2}-adsorption, H{sub 2}-TPD, isopropanol decomposition) and tested in the gas phase hydrogenation of benzene or as carbon materials in the hydrogen storage at room temperature and high pressure. The catalysts prepared exhibited better dispersion and activity than classical catalysts. TOF's of NiAg/SiO{sub 2} or Ni/carbon catalysts were similar to Pt catalysts in benzene hydrogenation. Differences in support acidity or preparation method and presence of Ag as metal additive play a crucial role in the chemical reduction of Ni by hydrazine and in the final properties of the materials. Ni/carbon catalysts could store significant amounts of hydrogen at room temperature and high pressure (0.53%/30 bars), probably through the hydrogen spillover effect. (author)

  10. CuO Nano-structures Prepared in Rosmarinus Officinalis Leaves Extract Medium: Efficient Catalysts for the Aqueous Media Preparation of Dihydropyrano[3, 2-c]chromene Derivatives.

    Science.gov (United States)

    Ghashang, Majid; Kargar, Mahboubeh; Shafiee, Mohammad R M; Mansoor, Syed S; Fazlinia, Abbas; Esfandiari, Hadi

    2015-01-01

    CuO nano-structures were prepared in Rosmarinus Officinalis leaves extract medium via a green bio-chemical method and were used for the one-pot synthesis of dihydropyrano [3,2-c] chromene derivatives. This procedure is very simple and the products were synthesized in high to excellent yields.

  11. Catalytic oxidation of n-hexane promoted by Ce{sub 1−x}Cu{sub x}O{sub 2} catalysts prepared by one-step polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, Vinícius D., E-mail: dantas@ursa.ifsc.usp.br [Instituto de Física, Universidade de São Paulo – USP, 13560-970 São Carlos, SP (Brazil); Lima, Maurício M. de [Instituto de Ciencia de los Materiales, Universidad de Valencia, E-46071 Valencia (Spain); Fundación General, Universitat de Valencia, Valencia (Spain); Cantarero, Andrés [Instituto de Ciencia de los Materiales, Universidad de Valencia, E-46071 Valencia (Spain); Bernardi, Maria I.B. [Instituto de Física, Universidade de São Paulo – USP, 13560-970 São Carlos, SP (Brazil); Bellido, Jorge D.A. [CAP-Engenharia Química, Universidade Federal de São João Del-Rei – UFSJ, São João Del-Rei, MG (Brazil); Assaf, Elisabete M. [Instituto de Química, Universidade de São Paulo – USP, 13560-970 São Carlos, SP (Brazil); Balzer, Rosana; Probst, Luiz F.D. [Departamento de Química, Universidade Federal de Santa Catarina – UFSC, 88040-900 Florianópolis, SC (Brazil); Fajardo, Humberto V. [Departamento de Química, Universidade Federal de Ouro Preto – UFOP, 35400-000 Ouro Preto, MG (Brazil)

    2013-11-01

    Ceria-supported copper catalysts (Ce{sub 1−x}Cu{sub x}O{sub 2}, with x (mol) = 0, 0.01, 0.03, 0.05 and 0.10) were prepared in one step through the polymeric precursor method. The textural properties of the catalysts were investigated by X-ray diffraction (XRD), Rietveld refinement, N{sub 2}-physisorption (BET surface area), electron paramagnetic resonance (EPR), UV–visible diffuse reflectance and photoluminescence spectroscopies and temperature-programmed reduction (TPR). In a previous study ceria-supported copper catalysts were found to be efficient in the preferential oxidation of CO. In this study, we extended the catalytic application of Ce{sub 1−x}Cu{sub x}O{sub 2} systems to n-hexane oxidation and it was verified that the catalysts were highly efficient in the proposed reaction. The best performance (up to 95% conversion) was observed for the catalysts with low copper loads (Ce{sub 0.97}Cu{sub 0.03}O{sub 2} and Ce{sub 0.99}Cu{sub 0.01}O{sub 2}, respectively). The physicochemical characterizations revealed that these behaviors could be attributed to the copper species present in the catalysts and the interaction between CuO and CeO{sub 2}, which vary according to the copper content. - Highlights: • Synthesis of CuO/CeO2 catalysts by the one-step polymeric precursor method. • 95% n-hexane conversion on Ce0.97Cu0.03O2 catalyst. • Redox properties play a key role in the catalytic performance.

  12. 混合催化剂催化蓖麻油合成蓖麻油多元醇%Preparation of Castor Oil Polyol by Mixed Catalyst

    Institute of Scientific and Technical Information of China (English)

    张立强; 张猛; 周永红; 胡丽红; 杨晓慧

    2013-01-01

    The castor oil polyols were prepared by using renewable castor oil as the main raw material,using sodium methoxide and triethanolamine as mixed catalyst,through transesterification reaction with cheap glycerol in nitrogen atmosphere.The effects of catalyst dosage,mass ratio,reaction temperature and reaction time on the conversion rate of castor oil monoglycerides,castor oil Kennedy diester and all product were investigated,respectively.The chemical structures,molecular mass and yield of the products were characterized by means of FT-IR,GPC.The optimum process was optimized by single variable experiment.The highest yield(92.54%) of castor oil polyol was obtained when mixed catalyst dosage was 0.75% of the castor oil mass,reaction temperature was 180 ℃,the mass ratio of castor oil and glycerol was 50 ∶ 12.33 and reaction time was 2.5 hours.Compared with sodium methoxide and tetrabutyl titanate as catalyst,not only the convention rate but also the hydroxyl value of the product was improved using the mixed catalyst,and the color of the product was reduced.%以可再生的蓖麻油为主要原料,首次采用甲醇钠和三乙醇胺为混合催化剂,与甘油在N2环境中发生酯交换反应,生成蓖麻油单甘脂和蓖麻油甘二酯.考察了催化剂用量、甘油用量、反应温度、反应时间对蓖麻油单甘脂转化率、蓖麻油甘二酯转化率和总转化率的影响,并与传统的催化剂甲醇钠、钛酸四丁酯催化酯交换反应进行了比较.采用FT-IR、GPC对产物的结构、相对分子质量和转化率进行了表征.通过单一变量控制法对反应的条件进行优化.结果表明,催化剂用量为蓖麻油质量的0.75%、蓖麻油和甘油的质量比为50∶12.33、反应温度为180℃、反应时间为2.5h时,蓖麻油多元醇的转化率最高,可达92.54%,与传统催化剂相比较,混合催化剂不仅提高了产物的转化率和羟值,而且使产品的色泽降低.

  13. Cu-exchanged heteropoly acids as efficient and reusable catalysts for preparation of 1-amidoalkyl-2-naphthols

    Indian Academy of Sciences (India)

    Hojatollah Khabazzadeh; Kazem Saidi; Neda Seyedi

    2009-07-01

    A series of amidoalkyl naphthols were prepared in high yields using various aldehydes and urea or amides. The reaction was catalysed by Cu1.5PMo12O40 (CuPMo) and Cu1.5PW12O40 (CuPW) and conducted in molten tetrabutylammonium bromide as an ionic liquid.

  14. PREPARATION AND PERFORMANCE OF MONOLITHIC CATALYST FOR TAR CRACKING%整体式焦油裂解催化剂的制备及性能研究

    Institute of Scientific and Technical Information of China (English)

    鲁敏; 吕鹏梅; 袁振宏; 李惠文; 许敬亮

    2011-01-01

    以堇青石为载体,采用真空浸渍法制备整体式镍基催化剂,研究了不同干燥方法对整体式催化剂内表面活性组分轴向分布的影响及不同工艺条件下的催化性能.结果表明:微波干燥法所得催化剂内表面活性组分轴向分布最均匀;重时空速对焦油裂解率的影响较大,当重时空速为177kg/(h·m3)时,焦油裂解率高达92.62%,H2的体积分数为46.53%;在较低温度条件(700~800℃)下,催化温度对焦油裂解的影响较小,当催化温度上升到900℃时,焦油裂解率大幅上升,单位质量生物质气体产率高达1.22Nm3/kg.%The Ni-based monolithic catalyst was prepared by vacuum impregnation with the support of cordierite. The influences of different drying methods to the axial distribution of active constituent in monolithic catalyst internal surface and the catalytic performance under different process conditions was studied. The results show that the axial distribution of catalyst internal surface active constituent is more homogeneous after microwaves drying. The weight hour space velocity (WHSV) has great influence on tar cracking rate. When the WHSV is 177kg/(h·m3), the tar cracking rate is 92.62% and H2 volume content is 46.53%. When the catalytic temperature is between 700 ~ 800℃, the variety of tar cracking rate is small, but when catalytic temperature rises to 900℃, the tar cracking rate can increase greatly and the gas yield can reach 1.22Nm3/kg per dried biomass.

  15. Preparation and Performance of Co-N-C Electro-Catalysts for Direct Methanol Fuel Cell%直接甲醇燃料电池用Co-N-C电催化剂的制备及性能

    Institute of Scientific and Technical Information of China (English)

    杨伟; 陈胜洲; 董新法; 林维明

    2012-01-01

    以三聚氰胺甲醛树脂和硝酸钴为前驱体,在Ar保护下采用高温碳化方法制备用于直接甲醇燃料电池( DMFC)阴极的含氮碳载钴(Co-N-C)氧还原电催化剂.利用热重与红外光谱联用、X射线衍射分析、元素分析等方法表征了催化剂的制备过程和结构,采用旋转圆盘电极测试考察了不同碳化温度对Co-N-C电催化剂氧还原催化活性的影响及电催化剂的耐醇性能,并采用该催化剂为阴极催化剂进行DMFC单电池测试.结果表明:Co-N-C电催化剂具有较高的电催化活性和较好的耐醇性能;其氧还原起始电位在0.5 V(vs.SCE)左右;700℃碳化温度下制备的Co-N-C电催化剂具有最高的氧还原催化活性.%Co-N-C oxygen reduction electro-catalysts for the cathode of the direct methanol fuel cell (DMFC) were first prepared via the pyrolysis in Ar atmosphere, with melamine formaldehyde resin and cobalt nitrate as the precursors. Then, the preparation and structure of the electro-catalysts were investigated by means of TG-FTIR, XRD and element analysis, and the electro-catalytic activity for oxygen reduction reaction as well as the methanol tolerance of the electro-catalysts was detected by using a rotating disk electrode. Finally, a DMFC single-cell test was carried out by using the prepared electro-catalysts as the cathode catalysts. The results indicate that Co-N-C electro-catalysts are of high electro-catalytic activity and strong methanol tolerance, and that the onset potential of the electro-catalysts for oxygen reduction is about 0.5 V (vs. SCE). Moreover, it is found that the catalyst prepared at 7001 possesses the highest electro-catalytic activity for oxygen reduction reaction.

  16. The influence of the hydrophobic agent, catalyst, solvent and water content on the wetting properties of the silica films prepared by one-step sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Ramezani, Maedeh, E-mail: m.ramezani@merc.ac.ir [Division of Nanotechnology and Advanced Materials, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Vaezi, Mohammad Reza [Division of Nanotechnology and Advanced Materials, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Kazemzadeh, Asghar [Division of Semiconductors, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of)

    2015-01-30

    Graphical abstract: - Highlights: • Transparent, hydrophobic, uniform silica film by sol–gel co-precursor process. • Preparation of silica coatings from ETES and Iso-OTMS in different molar ratios. • Decreasing in hydrophobicity of the films with increasing in Iso-TMS molar ratio. • By changing the molar ratio of component, different size of particles was obtained. - Abstract: In this paper, we used one-step sol–gel process to prepare the hydrophobic silica films on the glass substrate from the ethyltriethoxysilane (ETES) as a precursor and iso-octyltrimethoxysilane (Iso-OTMS) as a hydrophobic agent. In order to study the effect of the hydrophobic agent on the water repellent properties of the silica films, the alcosol was prepared by keeping constant the molar ratio of ETES:EtOH:H{sub 2}O at 1:36.2:6.3, with 6 M ammonium hydroxide and Iso-OTMS/ETES molar ratio varied from 0.2 to 1.4. Also, we investigated the influence of the other sol–gel reaction parameters, such as catalyst, solvent and water content and their effect on the morphology and hydrophobic properties of the silica films. The results revealed that by altering the molar ratio of NH{sub 4}OH, EtOH and H{sub 2}O, different sizes of silica nanoparticles from 41.24 to 86.16 nm were obtained. The silica films were characterized by atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM) images, contact angle measurement (CA) and percentage of optical transmission.

  17. The preparation and chemical reaction kinetics of tungsten bronze thin films and nitrobenzene with and without a catalyst

    Science.gov (United States)

    Materer, Nicholas F.; Apblett, Allen; Kadossov, Evgueni B.; Khan, Kashif Rashid; Casper, Walter; Hays, Kevin; Shams, Eman F.

    2016-06-01

    Microcrystalline tungsten bronze thin films were prepared using wet chemical techniques to reduce a tungsten oxide thin film that was prepared by thermal oxidation of a sputter deposited tungsten metal film on a quartz substrate. The crystallinity of these films was determined by X-ray diffraction and the surface was characterized by X-ray and Ultra-Violet Photoelectron spectroscopy. The total amount of hydrogen incorporated in the film was monitored using absorbance spectroscopy at 900 nm. The oxidation kinetics of the film and the hydrogenation of nitrobenzene in hexane were measured as a function of film thickness. A satisfactory fit of the resulting kinetics was obtained using a model that involves two simultaneous processes. The first one is the proton diffusion from the bulk of the film to the surface, and the second is a reaction of the surface protons with the oxidants. Finally, the dependence of the reaction rates on the presence of catalytic amounts of first row transition metals on the surface of the film was explored.

  18. Investigation on preparation of CuO-SnO2-CeO2/γ-Al2O3 catalysts for catalytic wet air oxidation process and their catalytic activity for degradation of phenol

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-jun; ZHANG Mi-lin; WAN Jia-feng; XIA Zhi; LIU Xiao-hui; LIU hui

    2008-01-01

    Catalytic Wet Air Oxidation process is an efficient measure for treatment of wastewater with great strength which is not biodegradable. Heterocatalysts now become the key investigation subject of catalytic wet air oxidation process due to their good stability and easy separation. In the paper, CuO-SnOE-CeO2/γ-Al2O3 catalysts are prepared by impregnation method, with SnO2 as a doping component, CuO as an active component, CeO2 as a structure stabilizer, γ-Al2O3 as a substrate. XPS test is carried out to investigate the effect of Sn on the chemical surrounding of Cu and O element on the catalyst surface and their catalytic activity. It is shown that the right do-ping of Sn can increase Cu+ content on the catalyst surface, as a result the quantity of adsorption oxygen is also increased. It is found that Cu + content on the catalyst surface is one of the primary factors that determin catalytic activity of catalyst through analyzing the catalytic wet air oxidation process of phenol.

  19. The Preparation of a Highly Efficient Ag3PO4/Ag/Bi2O2CO3 Photo-Catalyst and the Study of Its Photo-Catalytic Organic Synthesis Reaction Driven by Visible Light

    Directory of Open Access Journals (Sweden)

    Zhi Guo

    2017-09-01

    Full Text Available Ag3PO4/Ag/Bi2O2CO3 composites were prepared by a hydrothermal and precipitation method. The morphology, structure, and valence state of the photo-catalysts were characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, transmission electron microscopy (TEM, Scanning electron microscopy (SEM, Brunauer-Emmett-Teller (BET specific surface areas, and UV-vis diffuse reflectance spectra (UV-vis DRS. They were applied as heterogeneous catalysts in the synthesis of esters from aldehydes (or alcohols and alcohols and the synthesis of imines from alcohols and amines under visible light irradiation. The photo-catalytic activities of the esterification reactions of aldehydes and alcohols were heavily dependent on the loading of Ag3PO4/Ag/Bi2O2CO3 as well as the intensity and wavelength of the visible light. Furthermore, their conversion under visible light irradiation was superior to that in the dark. Herein a reaction mechanism from aldehydes and alcohols to esters was proposed, and the Ag3PO4/Ag/Bi2O2CO3 catalysts could be used six times without a significant decrease in activity. Using these catalysts under visible light could motivate future studies to develop efficient recyclable photo-catalysts and facilitate many synthetic organic reactions.

  20. Catalyst in Basic Oleochemicals

    Directory of Open Access Journals (Sweden)

    Eva Suyenty

    2007-10-01

    Full Text Available Currently Indonesia is the world largest palm oil producer with production volume reaching 16 million tones per annum. The high crude oil and ethylene prices in the last 3 – 4 years contribute to the healthy demand growth for basic oleochemicals: fatty acids and fatty alcohols. Oleochemicals are starting to replace crude oil derived products in various applications. As widely practiced in petrochemical industry, catalyst plays a very important role in the production of basic oleochemicals. Catalytic reactions are abound in the production of oleochemicals: Nickel based catalysts are used in the hydrogenation of unsaturated fatty acids; sodium methylate catalyst in the transesterification of triglycerides; sulfonic based polystyrene resin catalyst in esterification of fatty acids; and copper chromite/copper zinc catalyst in the high pressure hydrogenation of methyl esters or fatty acids to produce fatty alcohols. To maintain long catalyst life, it is crucial to ensure the absence of catalyst poisons and inhibitors in the feed. The preparation methods of nickel and copper chromite catalysts are as follows: precipitation, filtration, drying, and calcinations. Sodium methylate is derived from direct reaction of sodium metal and methanol under inert gas. The sulfonic based polystyrene resin is derived from sulfonation of polystyrene crosslinked with di-vinyl-benzene. © 2007 BCREC UNDIP. All rights reserved.[Presented at Symposium and Congress of MKICS 2007, 18-19 April 2007, Semarang, Indonesia][How to Cite: E. Suyenty, H. Sentosa, M. Agustine, S. Anwar, A. Lie, E. Sutanto. (2007. Catalyst in Basic Oleochemicals. Bulletin of Chemical Reaction Engineering and Catalysis, 2 (2-3: 22-31.  doi:10.9767/bcrec.2.2-3.6.22-31][How to Link/DOI: http://dx.doi.org/10.9767/bcrec.2.2-3.6.22-31 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/6