Boosting CO2 hydrogenation to light olefins with low CO selectivity through promoting HCOO* intermediates on Fe-ZnGa2O4/SAPO-34

CO2 hydrogenation to light olefins over oxide-zeolite (OX-ZEO) bifunctional catalysts has been considered as a promising solution towards Carbon Recycling, but still exists bottleneck problems in terms of low CO2 conversion efficiency and olefin yield. Facing to the challenges, we propose a strategy by stabilizing HCOO* intermediates and therefore inhibiting the COOH* pathway for the formation of CO byproducts through atomically doping Fe in ZnGa2O4 spinel. Various in situ characterizations and the dynamic analysis reveal quantitively that the highly dispersed Fe can facilitate the H* to attack the exposed C in adsorbed CO2* to enhance the CH3O* formation, promoting the consecutive olefin production. Coupling with SAPO-34, the optimized Fe-ZnGa2O4-2.5/SAPO-34 exhibits a high CO2 conversion efficiency of 26.6 % and C-2-C-4(=) yield of 12.5 % with an excellent stability for 200 h, providing a promising strategy for CO2 hydrogenation to light olefins.