Water dissociation and COOH formation on Fe modified Cu(100) surface: A density functional theory study

Abstract

Water splitting has emerged as a promising route for sustainable hydrogen production. In this research paper, adsorption and dissociation of H₂O accompanied with dissociated constituents reactions with CO₂ and CO have been investigated on Fe modified Cu(100) surface employing density functional theory (DFT) at GGA-PW91 level. The adsorption and other reactions carried out on Fe2–Cu(100) surfaces gave very promising results. The adsorption of H₂O on Fe top of this surface occurs yielding E_ads −1.73 eV, which highlights a favorable adsorption on the Fe-modified Cu(100) surface. The activation energy for the water splitting reaction is found to be 0.65 eV, suggesting a feasible pathway for hydrogen evolution. The process also accompanies reaction energy of −0.54 eV. Furthermore, the interaction between carbon dioxide (CO₂) and the H-atom on the surface lead to the formation of COOH through surmounting an activation barrier of 1.09 eV. The final position of COOH gets further stabilization having exothermicity of −0.43 eV. Another route for COOH formation from CO + OH operates on the Cu(100) part of the surface with a small activation barrier of 0.14 eV through exothermic process of −0.29 eV, however, diffusion of CO and OH from Fe to Cu is energetically expensive. This study signifies the consumption of CO and CO₂ in addition to water splitting giving birth to useful products.