Na-decorated binary spinel ferrite catalysts for the hydrogenation of CO₂ to olefins

Spinel ferrite catalysts, recognized for their unique physicochemical properties, have been extensively employed in CO₂ hydrogenation reactions. However, the specific roles of different transition metals in Na-decorated spinel ferrite for CO₂ hydrogenation to olefins remain underexplored. In this study, we designed a series of Na-decorated binary spinel ferrites by varying the type of the secondary metals. We found that doping with zinc reduces the hydrogenation ability, which enhances olefin selectivity. Conversely, adding copper facilitates catalyst reduction through H₂-spillover, with the CuFe interface increasing alcohol products. CoFe₂O₄ demonstrated the highest activity and olefin yield. Additionally, CoFe₂O₄ was found to promote the formation of the carbide phase and enhance the activation and dissociation of hydrogen, significantly boosting catalytic performance. Our findings pave the way for developing Na-decorated spinel catalysts tailored for selective olefin synthesis, with important implications for improving the efficiency of CO₂ hydrogenation processes.