Hybrid Catalyst Coupling Zn Single Atoms and CuNx Clusters for Synergetic Catalytic Reduction of CO2

Abstract

AbstractReverse water‐gas shift (RWGS) reaction is the initial and necessary step of CO2 hydrogenation to high value‐added products, and regulating the selectivity of CO is still a fundamental challenge. In the present study, an efficient catalyst (CuZnNx@C‐N) composed by Zn single atoms and Cu clusters stabilized by nitrogen sites is reported. It contains saturated four‐coordinate Zn‐N4 sites and low valence CuNx clusters. Monodisperse Zn induces the aggregation of pyridinic N to form Zn‐N4 and N4 structures, which show strong Lewis basicity and has strong adsorption for *CO2 and *COOH intermediates, but weak adsorption for *CO, thus greatly improves the CO2 conversion and CO selectivity. The catalyst calcined at 700 °C exhibits the highest CO2 conversion of 43.6% under atmospheric pressure, which is 18.33 times of Cu‐ZnO and close to the thermodynamic equilibrium conversion rate (49.9%) of CO2. In the catalytic process, CuNx not only adsorbs and activates H2, but also cooperates with the adjacent Zn‐N4 and N4 structures to jointly activate CO2 molecules and further promotes the hydrogenation of CO2. This synergistic mechanism will provide new insights for developing efficient hydrogenation catalysts.