Systematic DFT studies of CO-Tolerance and CO oxidation on Cu-doped Ni surfaces

Abstract

Nickel-based surfaces have received significant attention as an efficient substrate for electrooxidation. This work studied doped nickel surfaces with Cu atoms to enhance the CO-Tolerance. A comparative study was performed for CO adsorption upon different cleavage facets of pristine and Cu-doped nickel surfaces, whereas the adsorption energy, charge transfer, and density of state for CO were estimated using GGA-RPBE calculation method. Several adsorption probabilities were considered, and the change in adsorption energy and bond lengths were used to explain the CO adsorption mechanism. Otherwise, the density of state was employed to study the 3σ and 1π orbital to demonstrate the adsorption of CO onto the different facets. According to our analysis, the Cu-doped nickel surface showed higher CO tolerance than the pristine nickel surface. Whereas the calculated CO adsorption energies of Cu-doped surfaces have more positive values than the non-doped counterparts. The catalytic ability of pristine and Cu-doped Ni(111) was studied to evaluate the ability of surface poisoning resistance. Thus, oxidation of CO to CO2 was studied using the Eley-Rideal mechanism upon the pristine and Cu-doped surfaces of Ni(100) where the rate-determining step for CO oxidation upon the reported surfaces was estimated as CO + O2* → CO2* + O* by an energy barrier of 1.05 and 0.9 eV for pristine, and Cu-doped Ni (100).