Abstract
Nickel impregnated Pt/H-β and Pt/H-MOR catalysts with different Ni content were prepared and subjected to hydroisomerization of n-hexane in the presence of flowing H2 gas. The states of Pt and Ni were identified by ESCA. The particle size measured by TEM shows that average particle size increases with increasing Ni loading. The acidity of the catalysts was measured by TPD of ammonia. The catalytic activity of Ni containing and Ni free Pt/H-β and Pt/H-MOR catalysts was compared and found that addition of Ni up to a threshold value (0.3 wt% for β and 0.1 wt% for MOR) increases the n-hexane conversion and dimethyl butanes selectivity due to better metal-acid synergism and decreases the amount of cracked products. When the Ni amount exceeds the threshold values the conversion decreases and cracked products increase. Further the Ni impregnation of Pt containing acidic supports increases the sustainability of the catalysts and was found to favor the protonated cyclopropane (PCP) intermediate mechanism in n-hexane isomerization. β zeolite was found to be a better potential support than mordenite and the isomerized product mixture shows better octane number.
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Anderson, J. R. and Avery, N. R., “The Isomerization of Aliphatic Hy-drocarbons over Evaporated Films of Platinum and Palladium”,J. Catal,5, 446 (1966).
Arribas, M. A., Marquez, F. and Martinez, A., “Activity, Selectivity, and Sulphur Resistance of Pt/WOx-ZrO2 and Pt/Beta Catalysts for the Simultaneous Hydrosiomerisation of n-heptane and Hydrogenation of Benzene”,J. Catal,190, 309 (2000).
Bertolini, J. C., Tardy, B., Abon, M., Billy, J., Delichere, P. and Mas-sardier, J., “Surface Reactivity of Platinum-Nickel Single Crystal Alloys: Carbon Monoxide Adsorption”,Surf. Sci.,135, 117 (1983).
Blomsma, E., Martens, J. A. and Jacobs, P. A., “Isomerization and Hy-drocracking of Heptane over Bimetallic Bifunctional PtPd/H-Beta and PtPd/USY Zeolite Catalysts”,J. Catal.,165, 241 (1997).
Blomsma, E., Martins, J. A. and Jacobs, P. A., “Reaction Mechanisms of Isomerization and Cracking of Heptane on Pd/H-Beta Zeolite”,J. Catal.,155, 141 (1995).
Brouwer, D.M., “Chemsitry and Chemical Engineering of Catalytic Pro-cesses”, Prins, R. Schult, G. C. A., Eds., Sijthof and Noordhoff, Ger-mantown,M.D. (1980).
Canizares, P. de Lucas, A., Dorado, F, Duran, A., Asencio,, “Char-acterisation of Ni and Pd Supported on H-Mordenite Catalysts: Influ-ence of the Metal leading Method”,Appl. Catal A: General.,169, 137 (1998).
Chen, J. K., Martin, A. M., Kim, Y. G. and John, V. T, “Competitive Reaction in Intrazeolitic Media”,Ind. Eng. Chem. Res.,27, 401 (1988).
Chu, H. Y, Rosynek, M. P. and Lunsford, J. H., “Skeletal Isomerization of Hexane over Pt/H-Beta Zeolite: Is the Classical Mechanism Cor-rect?”,J. Catal.,178, 352 (1998).
Condon, F E., “Catalytic Isomerization of Hydrocarbons”,Cataly-sis,1, 6 (1958).
Corolleur, C., Corolleur, S. and Gault, F G., “The Mechanism of Hy-drogenolysis and Isomerization of Hydrocarbons on Metals. VI. Iso-merization of Labeled Hexanes on a 0.2% Platinum-Alumina Cata-lyst”,J. Catal.,24, 385 (1972).
Deannan, T. F. and Kennedy, C. R., “Impact of Catalyst Acid/Metal Bal-ance in Hydroisomerization of Normal Paraffins”,AIChE J.,39(4), 607 (1993).
Glannetto, G. E., Perot, G. E. and Guisnet, M. R., “Hydrosiomerization and Hydrocracking of n-Alkanes. 1. Ideal Hydroisomerisation PtHY Catalysts”,Ind. Eng. Chem. Prod. Res. Dev.,25, 481 (1986).
Higgins, J. B., Lapierre, R. B., Schlenker, J. L., Rohrman, A. C. and Wood, J. D., “The Framework Topology of Zeolite Beta”,Zeolite,8, 446 (1988).
Iglesia, E., Soled, S. L. and Kramer, G. M., “Isomerization of Alkanes on Sulfated Zirconia: Promotion by Pt and by Adamantyl Hydride Transfer Species”,J. Catal.,144, 238 (1993).
Jao, R. M., Lin, T B. and Chang, J.-R., “Light Naphtha Isomerization over Mordenite-supported Ni-Pt Catalysts: Effects of Ni on the Catalytic Performance for Pure Feed and Sulphur Containing Feed”,J. Catal.,161, 222 (1996).
Jordao, H., Simoes, V., Montes, A. and Cardoso, D., “Bifunctional Ni, Pt Zeolite Catalysts for the Isomerization of n-Hexane;Stud. Surf. Sci. Catal.,130, 2387 (2000).
Lee, J. K. and Rhee, H.-K., “Characteristics of Pt/H-Beta and Pt/H-Mordenite Catalysts for Isomerization of n-Hexane”,Catal. Today,38, 235 (1997).
Leu, L.-J., Hov, L.-Y, Kang, B.-C., Li, C., Wu, S.-T. and Wu, J.-C., “Syn-thesis of Zeolite Β and Catalytic Isomerization of n-Hexane over Pt/ H-Β Catalysts”,Appl. Catal.,69, 49 (1991).
Lugstein, A., Jentys, A. and Vinek, H., “Hydroconversion of n-Heptane over Co/Ni Containing HZSM-5”,Appl. Catal., A: General,152, 93 (1997).
Malyala, R V, Rode, C. V., Arai, M., Hegde, S. G. and Chaudhari, R V., “Activity, Selectivity and Stability of Ni and Bimetallic Ni-Pt Sup-ported on Zeolite Y Catalysts for Hydrogenation of Acetophenone and its Substituted Derivatives”,Appl. Catal., A: General,193, 71 (2000).
Minchev, Ch., Knazirev, V., Kosova, L., Pechev, V., Grunsser, W. and Schmidt, F in L.V.C., Rees (Editor). Proc. 5th Int. Conf. Zeolites, Hey-den, London, 335 (1980).
Narayanan, S., “XPS Studies on the Reduction of Nickel Mordenite”,Zeolite,4(3), 231 (1984).
Sinha, A. K. and Sivasanker, S., “Hydroisomerisation of n-Hexane over Pt-SAPO-11 and Pt-SAPO_31 Molecular Sieves;Catal. Today,49, 293 (1999).
Tiong Sie, S., “Acid Catalysed Cracking of Paraffinic Hydrocarbons. 1. Discussion of Existing Mechanisms and Proposal of a New Mecha-nism”,Ind. Eng. Chem. Res.,31, 1881 (1992).
Weisz, P. B. and Prater, C. D., “Interpretation of Measurements in Experimental Catalysis”,Advan. Catal.,6, 413 (1954).
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Eswaramoorthi, I., Lingappan, N. Nickel impregnated Pt/H-β and Pt/H-mordenite catalysts for hydroisomerization of n-hexane. Korean J. Chem. Eng. 20, 207–216 (2003). https://doi.org/10.1007/BF02697230
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DOI: https://doi.org/10.1007/BF02697230