Highly Active Catalytic CO2 Hydrogenation to Lower Olefins via Spinel ZnGaOx Combined with SAPO‐34

A key primary method for creating a carbon cycle and carbon neutrality is the catalytic hydrogenation of CO2 into high value‐added chemicals or fuels. In this work, ZnGaOx oxides were prepared by parallel co‐precipitation and physically mixed with SAPO‐34 molecular sieves prepared by hydrothermal synthesis to produce ZnGaOx/SAPO‐34 bifunctional catalysts, which were evaluated for the catalytic synthesis of lower olefins (C2=−C4=) from carbon dioxide hydrogenation. It was demonstrated that the reaction process requires oxygen defect activation, synergistic hydrogenation, and CO2 alkaline adsorption of ZnGaOx. The spinel structure of ZnGaOx has more abundant oxygen defects and alkaline adsorption sites than the ZnGaOx solid solution, which effectively enhances the catalytic performance. The CO2 conversion was 28.52%, the selectivity of C2=−C4= in hydrocarbons reached 70.01%, and the single‐pass yield of C2=−C4= was 10.95% at 370 °C, 3.0 MPa, and 4800 mL/gcat/h. The introduction of an appropriate amount of Ga into ZnO can effectively increase the oxygen defect concentration and CO2 adsorption capacity of ZnGaOx, resulting in a significant improvement in the performance of ZnGaOx/SAPO‐34 catalyzed direct hydrogenation of CO2 to lower olefins.