Theoretical Insights into CO2Activation and Reduction on the Ag(111) Monolayer Supported on a ZnO(0001) Substrate

First principles calculations are performed to investigate CO 2 adsorption and reduction on Ag(111)/ZnO(000 1 ) surfaces and interfaces. First, the pristine Ag(111) surface turns out to be quite noble for CO 2 adsorption, as its d-band states are located well below the Fermi level. The d-band states of the Ag(111) surface are subject to a tensile strain slightly shifting toward the Fermi level. However, the d-band center is still far away from the Fermi level. A critical change of the d-band states is obtained when the stretched Ag(111) monolayer is supported on the ZnO(000 1 ) substrate. The binding ability between the supported Ag(111) monolayer and CO 2 molecule is an intermediate strength. Thus, the CO 2 reduction in the subsequent hydrogenation process is optimized as well. Furthermore, we demonstrate that the stretched Ag(111) monolayer supported on the ZnO(000 1 ) substrate is indeed stable under H 2 -rich conditions. This surface can even maintain the improved ability for CO 2 adsorption and reduction in the presence of Zn impurities.