Development of Mg-Modified Fe-Based Catalysts for Low-Concentration CO2 Hydrogenation to Olefins

With mounting concerns about reducing carbon emissions, developing a catalyst that can be used in the hydrogenation of CO2 to olefins makes sense. Considering the high cost of CO2 capture, the direct use of low-concentration CO2 to produce olefins is more promising. In this work, we develop a reliable Mg-modified Fe-based catalyst for the low-concentration hydrogenation of CO2 to olefins. The optimized KFeMnMg0.15 catalyst exhibits a high olefin yield of 15.4% with an olefin selectivity of 61.2% at a low CO2 concentration of 10%. The structural characterizations reveal that the Mg promoter regulates the adsorption strength of reactants CO2 and H2, and the intermediate is CO, which promotes the conversion of CO2 and inhibits the hydrogenation of olefins. In addition, the Mg promoter plays a critical role in facilitating the formation of iron carbide, which is the active phase of the hydrogenation of CO2 to olefins. Thus, multiple functions of the Mg promoter realize the efficient conversion of low-concentration CO2 to olefins.