DFT Study of adsorption and diffusion of CO2 on bimetallic surfaces

In this work, adsorption and diffusion of CO2 on the Cu (111) surface, and Cu (111) surface modified by tungsten (W) and platinum (Pt) were studied and their electronic properties were examined using Density-functional theory (DFT) simulations. To specify the most favourable adsorption sites, the adsorption energies and distances of CO2 on various surface sites including on top, hexagonal close-packed (HCP), and bridge were calculated. The crystal orbital overlap population analysis was employed to investigate the properties and characteristics of chemical bonding. The computed Bader atomic charges of CO2 molecules on different catalyst surfaces indicated that the Cu-W alloy surface had a higher net charge transfer than other surfaces. This result suggests that the adsorption of CO2 on the Cu-W alloy surface is more powerful than on other surfaces. The outcomes indicated that the CO2 adsorption on the surfaces follows the order of Cu-W alloy > Cu-Pt alloy > Cu. Also, the diffusion on the alloy surfaces was faster than on the Cu surface, which confirms the adsorption energy.