Enhanced Liquid Fuel Production from CO2 Hydrogenation: Catalytic Performance of Bimetallic Catalysts over a Two‐Stage Reactor System

Abstract

AbstractA bimetallic catalyst combining Fe and Co active sites enables direct conversion of CO2 to hydrocarbons with a higher activity but modest CO selectivity compared with a sole Fe catalyst. The introduction of cobalt metal increases the adsorption ability of CO2, which promotes the CO2 activation over iron species through RWGS reaction. Besides, the carbide content (Fe5C2) also increases significantly with the further introduction of cobalt metal in comparison to potassium modified one, achieving a high C−C bond coupling activity. On the basis, the catalytic performance of CO2 hydrogenation over this bimetallic catalyst was investigated in a two‐stage reactor system, where the influence of number of reactors on CO2 conversion and the catalytic performance over each reactor were analysed regarding the yield of liquid fuel. A significant increase in liquid fuel production was achieved under ordinary conditions. It was proven that ex situ water removal plays the determining role in the integrated process for improving the catalytic activity and lowering the selectivity of undesired CO by‐product. The utilization of a two‐stage reactor system promotes CO2 conversion, making the CO2 conversion approaching a higher value (69.9%). Meanwhile, the yield of liquid fuel exceeds 300 gfuels/(kgcath) under conventional conditions.