Role of Y2O3 in Cu/ZnO/Y2O3 catalysts for CO2 hydrogenation to methanol

Abstract

CuZn-based catalyst is an attractive catalyst for methanol synthesis from CO₂ hydrogenation, but it early deactivates and its methanol yield still needs to improve. In this study, Y₂O₃ was introduced to Cu/ZnO using a one-pot hydrothermal method, and exhibits a synergistic effect of ZnO and Y₂O₃ on enhancing methanol yield and the stability. We found that the interaction between Y₂O₃ and ZnO results in abundant oxygen vacancies formation, thereby enhancing CO₂ adsorption and activation. Kinetic analysis and in situ DRIFTS suggest that RWGS forming CO and methanol formation compete for a mutual intermediate HCOO*, and the introduction of Y₂O₃ to Cu/ZnO raises the energy barrier for the CO formation but lowers that for methanol formation, thus enhancing the methanol yield on Cu/ZnO/Y₂O₃.