Computational analysis of atomic C and S adsorption on Ni, Cu, and Ni-Cu SOFC anode surfaces

Carbon deposition and sulfur poisoning are issues that limit the state-of-the-art Ni-YSZ anode material of solid oxide fuel cell to be used in direct hydro-carbon fuels. In the present study, density functional theory calculations are performed to investigate the adsorption of C and S on Ni(111), Cu(111) and alloyed Ni-Cu(111) surfaces. It is confirmed that C and S energetically favor the hollow sites of Ni(111) and Cu(111) surfaces; forming Ni-Cu alloy by addition of Cu into Ni weakens the adsorption of C and S with lowered adsorption energies due to less overlapping between the C 2p or S 3p and the metallic 3d orbits.