Unravelling the role of Y in Cu/ZnO/ZrO2 catalysts for CO2 hydrogenation to methanol

A detailed understanding of the role of Y in Cu/ZnO/ZrO 2 catalysts for methanol synthesis was studied by XRD, HRTEM, TPR, TPD, N 2 O titration and XPS techniques in this work. The addition of Y enhances the interaction between Cu and ZnO. With the increase of Y content, the crystal size of Cu and ZnO decreased and Cu 0 surface area increased, CO 2 /H 2 -TPD exhibited the larger CO 2 and H 2 desorption peak at relative high temperature, XPS confirmed the reduction degree of ZnO to Zn 0 on the catalyst surface also increased, and forming more Cu-ZnO x active sites. However, excess Y content leads to a much stronger interaction between Cu and ZnO, which is not beneficial for migration and stabilization of the formed ZnO x species during the reaction atmosphere, and thus generating less Cu-ZnO x sites for methanol synthesis. This work enlightens the migratable and metastabe of the formed ZnO x species on Cu surface by regulation of promoter and offers a perspective for exploring Cu-ZnO interactions in modified Cu/ZnO/ZrO 2 catalysts.