Manganese-Promoted Fe₃O₄ Microsphere for Efficient Conversion of CO₂ to Light Olefins

Abstract

In this work, manganese well-dispersed on Fe3O4 microsphere (Mn–Fe3O4) catalyst was synthesized. It exhibited excellent catalytic performance for the direct conversion of carbon dioxide (CO2) into light olefins. A CO2 conversion of 44.7% with high selectivity of light olefin (46.2%, yield of 18.7%), high O/P ratio (6.5), and low selectivity of CO (9.4%) was obtained over the 10Mn–Fe3O4 catalyst. The Mn–Fe3O4 catalyst was studied by XRD, SEM, (HR)TEM, STEM–EDS, H2-TPR, and CO2-TPD. The result indicated that the manganese promoter could facilitate the adsorption of CO2 and the activation of C═O bonds as well as inhibit the secondary hydrogenation. This work offered a novel Fe-based catalyst system to the utilization of CO2 and an understanding in promoting C═O bond activation in the first step of CO2 hydrogenation to hydrocarbon reaction.