Effects of indium promoter on iron-based catalysts for CO2 hydrogenation to hydrocarbons

Abstract

Conversion of CO2 to value-added chemicals by hydrogenation is considered as a promising way for CO2 utilization. Addition of promoters into iron-based catalysts is a crucial strategy to enhance the catalytic performance in CO2 hydrogenation. In this work, indium (In) was introduced into iron-based catalyst as a promoter to improve the conversion efficiency of CO2. The promotional effects of In on CO2 hydrogenation were also studied by varying In loading. In promoter can accelerate the reduction of ferric oxide in iron-based catalysts. The evolution of In species had a significant influence on iron species during reaction, leading to the obvious induction period for the In-promoted catalysts with more than 3 wt% In loadings. Addition of In enhanced the adsorption of CO2, and obviously improved the CO2 conversion. The CO selectivity over In-promoted catalysts slightly decreased, while the distribution of hydrocarbons changed a little. The CO2 conversion over 10Fe2In1K/Al2O3 increased 17% compared with that over the benchmark 10Fe1K/Al2O3 catalyst. The insights into the promotional effects of In provides a value choice to design iron-based catalysts for CO2 hydrogenation.