Theoretical Study on Copper Adsorption on Zinc Oxide Surfaces to methanol

The study of copper on zinc oxide surfaces is a topic of ongoing research due to the importance of copper as a promoter in the low-temperature synthesis of methanol, the water-gas shift process and methanol steam reforming. The role of zinc oxide in supporting the stabilisation of the copper atoms and promoting the CO2 hydrogenation reaction is multifaceted and involves a range of physical and chemical factors. In this work, we used density functional theory (DFT) calculations to investigate the copper adsorption on zinc oxide surfaces on different sites. Bader charge analysis, adsorption energy and phonon inelastic neutron scattering (INS) associated with most stable systems were calculated and compared with previous theoretical and experimental results. We found that atomic copper adsorption on hollow site of ZnO(111) is the most stable and favourable site for copper adsorption compared to other zinc oxide surfaces. This is due to the strong metal- oxygen interaction between copper and the zinc oxide surface. We concluded that further studies are needed to investigate the catalytic activity of this catalyst under realistic reaction conditions with realistic models of copper supported on zinc oxide.