Active site structure study of Cu/Plate ZnO model catalysts for CO2 hydrogenation to methanol under the real reaction conditions

Plate-like ZnO, dominantly exposed (002) polar facet, supported Cu catalysts were prepared by impregnation method as model catalysts for CO2 hydrogenation to methanol under the real reaction conditions. The catalysts were thoroughly characterized by Scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), in situ Raman spectra, Temperature-programmed reduction (H-2-TPR) and CO2 Temperature-programmed desorption (CO2-TPD). Catalyst microstructures can be obviously tuned through the increasing of Cu content, interface constituted by Cu-Plate ZnO direct contact, interface constituted by Cu (on ZnO) covered by migrated ZnOx and interface constituted by isolated Cu nanoparticles covered by migrated ZnOx. These microstructures displayed different catalytic performance for CO2 hydrogenation to methanol; among them, interface caused by the migrated ZnOx covered Cu nanoparticles should play vital roles for methanol production.