Specific performance of silica-coated Ni catalysts for the partial oxidation of methane to synthesis gas

• Published in: Journal of catalysis 2007-01, Vol.245 (2), p.392-400
• Main Authors: Takenaka, Sakae, Umebayashi, Hiroshi, Tanabe, Eishi, Matsune, Hideki, Kishida, Masahiro
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Catalysis; Catalysts; Chemistry; Colloidal state and disperse state; Emulsions. Microemulsions. Foams; Exact sciences and technology; General and physical chemistry; Microemulsion; Nickel; Oxidation; Partial oxidation of methane; Silica; Silica-coated Ni catalyst; Silica-supported Ni catalyst; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2006.11.005

Silica-supported Ni catalysts were prepared by using water-in-oil typed microemulsion. By preparation using the microemulsion, Ni metal particles with diameters < ca. 5 nm were covered uniformly with silica layers with thickness of ca. 10 nm, whereas Ni metal particles were supported on the outer surface of silica by a conventional impregnation method. The Ni metal covered with silica (coat-Ni) showed excellent catalytic performance for the partial oxidation of methane into synthesis gas. Coat-Ni showed a high activity and a long life for the partial oxidation of methane at temperatures above 973 K to form CO and hydrogen, whereas Ni metal catalyst supported on silica was rapidly deactivated for the reaction. Ni K-edge XANES/EXAFS and temperature-programmed reduction for these catalysts showed that Ni metal particles in coat-Ni strongly interacted with silica. The strong interaction of Ni metal particles with silica would improve their catalytic performance for the partial oxidation of methane into synthesis gas.