Hydrogen production by steam reforming of n-butane over supported Ni and Pt-Ni catalysts

Steam reforming of n-butane over Ni/delta-Al2O3 and Pt-Ni/delta-Al2O3 catalysts was studied at temperatures between 578 and 678K. The major difference between the two catalysts was found to be at 648 K, at which Pt-Ni/delta-Al2O3 showed superior performance in terms of selective hydrogen production that resulted in lower carbon dioxide and methane formation. Carbon monoxide was not observed over either catalyst at 648 K, but was produced in small quantities at 678 K. No coke formation was detected under the reaction conditions used. Both catalysts exhibited activities increasing with temperature. At 678 K, complete n-butane conversion was achieved over bimetallic Pt-Ni, while 67% conversion was obtained over Ni. Studies for evaluating reaction kinetics over the Pt-Ni/delta-Al2O3 catalyst conducted under differential conditions at 648 K gave reaction orders of 1.20 and -0.18 with respect to n-butane and steam, respectively. Activation energy of the reaction was found to be 80.7 +/- 7.7 U/mol in the 603-668 K range. (C) 2003 Elsevier B.V. All rights reserved.