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

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 Eads −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. [Display omitted] •Adsorption of H2O on the bimetallic Fe2–Cu(100) surface is chemical in nature.•Activation energy for water splitting is much lower than the adsorption energy.•The water splitting is exothermic occurring at low barrier.•CO2 interaction with H leads to COOH formation.•Bimetallic surface is superior to its counter pure parts for the reaction showing synergy.