DFT Study of adsorption and diffusion of CO₂ on bimetallic surfaces

ABSTRACT

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.

KEYWORDS:

• Adsorption
• bimetallic surfaces
• copper
• platinum
• tungsten

Acknowledgment

The authors of this work appreciate the financial support of the Ferdowsi University of Mashhad Research Council, Mashhad, Iran (Grant No. 3/58558).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Ferdowsi University of Mashhad: [grant number 3/58558].