SiO2-coated FeK/Al2O3 catalysts with different silica content were prepared and examined for the synthesis of hydrocarbons from CO2 hydrogenation. It was found that SiO 2 coating affects both the activity for CO2 conversion and the selectivity to higher hydrocarbons, depending on the loading level. The catalyst with 9 wt% SiO2 coating showed both high CO2 conversion (63%) and high selectivity toward C2+ hydrocarbons (74%), while further higher coating led to suppression of catalyst activity. The analytical characterization of SiO2-coated catalysts confirmed the interactions of SiO2-Fe and SiO2-Al2O 3, which largely reduced the metal-support interaction and decreased the reduction temperature of iron oxide. In addition, an increase of adsorption capacity for CO was observed with desired SiO2 coating. It is likely that SiO2-coating improved the catalyst hydrophobic property, thereby reducing the negative impact of water by-product and facilitating the reverse water gas shift reaction and subsequent hydrogenation towards higher CO 2 conversion to higher hydrocarbons.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)