The preparation and use of high surface area silicon carbide catalyst supports

Abstract

High surface area SiC has been prepared in a tubular reactor by the high-temperature, vapor phase decomposition of Si-containing compounds such as tetramethylsilane. Surface areas near 50 m 2 g −1 for β-phase SiC were obtained in these initial experiments. These powders did not sinter during heating to 1173 K, even in the presence of oxygen, and surface areas actually increased somewhat due to burnoff of residual elemental carbon. Using these SiC powders as a support resulted in well-dispersed Pt/SiC catalysts which possessed normal kinetic behavior for methanation. However, Ni/SiC catalysts exhibited unusual chemisorption behavior, a range of activity for CO hydrogenation, and selectivity only to methane.