Cobalt supported on alumina and silica-doped alumina: Catalyst structure and catalytic performance in Fischer―Tropsch synthesis

Abstract The paper addresses the structure and catalytic performance in fixed bed reactor at 20 bars of cobalt Fischer–Tropsch catalysts supported by commercial alumina (Puralox) and silica-doped alumina (Siralox). The cobalt loading varied between 8 and 15 wt.%; both alumina and silica-doped alumina supports had similar textural properties. Cobalt dispersion in both supports was principally affected by support pore diameter; at high cobalt loadings, cobalt particle size slightly increased with cobalt content. The presence of small amounts of silica in alumina (5 wt.% SiO2) enhanced cobalt reducibility and hindered formation of hardly reducible cobalt aluminate species. Higher Fischer–Tropsch reaction rate over cobalt catalysts supported on silica-doped alumina was attributed to a better cobalt reducibility.

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