A first-principles study of C + O reaction on NiCo(1 1 1) surface

A density-functional theory method has been conducted to investigate the association of C + O on (1 1 1) facets of ordered NiCo alloy and the results have been compared with those obtained on pure Ni(1 1 1) surface. In reaction of C + O, the favorable reaction path is that C adsorbed on HCP-1 site moves to the nearest Ni-Co bridge site, and associates with O migrating from FCC-1 site to result in CO adsorbed on the bridge site of Ni-Co. However, the reaction barrier is higher by 0.35 eV than that on pure Ni(1 1 1), which indicates that the incorporation of Co into the Ni crystal is not in favor of the reaction of carbon delimination.

Highlights► Build the model of NiCo(1 1 1) slab. ► Adsorption energies of C and CO are lower on NiCo(1 1 1) than those on Ni(1 1 1). ► Reaction barrier of association of C + O is increased by 0.35 eV. ► Incorporation of Co into the Ni crystal is not in favor of carbon elimination.