Catalytic Activity of Single Transition-Metal Atom Doped in Cu(111) Surface for Heterogeneous Hydrogenation

Single-atom alloy (SAA) has been considered as an effective strategy to achieve excellent catalytic performance toward heterogeneous hydrogenation. We have performed first-principles calculations for SAAs of Cu(111) with nine different transition-metal (TM) elements of the group VIIIB (TM = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, and Pt). The thermodynamic stability and the catalytic activity of these SAAs have been systematically investigated. It has been found that the SAA of Cu(111) surface doped by a single Ni, Rh, Pd, or Pt atom can stably exist. There are only three SAAs alloyed with Ni, Pd, and Pt that exhibit a lower energy barrier of H-atom diffusion with respect to that of H-2 dissociation, facilitating the spillover of H atoms. Ab initio molecular dynamics simulations have confirmed the results obtained from the energetic calculations. It is interesting to see that Ni and Pt are more suitable than the Pd as the alloying element of Cu, owing to the lower activation energies of H-2 dissociation. Our results will be important for improving the catalytic performance of SAAs for the industrially important hydrogenation reactions.