Atomic oxygen adsorption on Au (1 0 0) and bimetallic Au/M (M = Pt and Cu) surfaces

Periodic slab calculations in generalized gradient approximation density–functional theory (GGA–DFT) have been used to demonstrate how the existence of second metals can modify the atomic oxygen adsorption on Au (1 0 0) surfaces. The computed adsorption energies for atomic oxygen adsorbed at 0.125 ML (monolayer) surface coverage on the Au (1 0 0) and bimetallic Au–Pt (1 0 0), Au–Cu (1 0 0), Au–Pt–Au (1 0 0) and Au–Cu–Au (1 0 0) surfaces are 275.60, 417.96, 427.79, 283.38, and 275.55 kJ/mol, respectively. In all coverages, the adsorption energies E ad O for Au–Pt and Au–Cu surfaces are higher than that for Au–Pt–Au, Au and Au–Cu–Au. In low coverage (θ < 0.5), the adsorption energy E ad O for Au–Cu is larger than that for Au–Pt. As the coverage rises, E ad O reduces and E ad O for Au–Cu becomes smaller than that for Au–Pt. In Au–Cu–Au (1 0 0) surface, the largest shift in the d-band center away from the Fermi level results in the weakest oxygen binding energy.