Deactivation Behavior of Co/SiC Fischer-Tropsch Catalysts by Formation of Filamentous Carbon

Abstract

Silicon carbide (SiC) having high thermal conductivity and macro-porosity was investigated for the Fischer-Tropsch Synthesis (FTS) reaction over Co-based catalysts in order to elucidate its support effects by surface modification with alumina. Even at a low temperature of around 230 A degrees C, filamentous carbon formation was observed on the unmodified Co/SiC catalyst possessing large cobalt crystallites with a weak metal-support interaction. On the contrary, the cobalt catalyst supported on the alumina-modified SiC was found to be superior with respect to the CO conversion and stability. Even though the dispersion of cobalt oxides on the alumina-modified SiC support was not significantly improved, the remarkable performance improvements of the alumina-modified Co/SiC catalyst were mainly attributed to the enhanced metal-support interaction by the added alumina which suppressed the filamentous carbon formation.