Key Role of Metal Oxide Support in Tuning Active Surface Components of Fe-Based Catalysts for CO2 Hydrogenation

Currently, Fe-based catalysts are a highly promising option for CO2 hydrogenation to produce hydrocarbon products, including light olefins, but understanding the behaviors of catalytically active Fe-containing phases and supports is key to regulating the catalytic performance. Here, we synthesized different metal oxide (i.e., TiO2, ZrO2, Al2O3, and CeO2)-supported Fe catalysts for CO2 hydrogenation to produce hydrocarbons through varying metal–support interactions in catalyst precursors. It was demonstrated that Fe/ZrO2 and Fe/Al2O3 catalysts exhibited superior catalytic activity and selectivity of light olefins compared to other supported Fe catalysts. Combining multiple structural characterizations with catalytic experimental results, it was revealed that for the Fe/ZrO2 catalyst, appropriately strong Fe–support interactions facilitated the generation of a large amount of defective FeOx component and a certain amount of iron carbides, thus constructing a favorable synergistic catalysis to benefit activated adsorption of CO2 and H2 and CO intermediate dissociation and thus promote the generation of light olefins. The findings highlight the pivotal role of metal–support interactions in precisely tuning the overall catalytic behavior of Fe-based catalysts and offer deep insights into the synergistic effect of catalytically active surface species on catalysts for CO2 hydrogenation.