One-step production of C1–C18 alcohols via Fischer-Tropsch reaction over activated carbon-supported cobalt catalysts: Promotional effect of modification by SiO2

Abstract

The promotional effect of SiO2 on the catalytic synthesis of mixed C1–C18 alcohols from syngas using the Fischer-Tropsch reaction over activated carbon-supported cobalt catalysts was investigated. X-ray diffraction, H2 temperature-programmed reduction, pulsed CO chemisorption and N2 physisorption techniques were all employed to assess the catalyst. Although the addition of SiO2 decreased the reducibility of the Co component, Co dispersion was significantly increased and its aggregation during reaction was inhibited, resulting in greatly enhanced reaction activity. Appropriate amounts of SiO2 also promoted the formation of Co2C, leading to an increased selectivity for C1–C18 alcohols. More importantly, the addition of SiO2 favored the formation of higher molecular mass alcohols (C6–C18) by suppressing Co reduction, thus producing an abundance of Co(II) species capable of facilitating CO insertion.