Oxygen reduction reaction on Pt-skin PtV(111) fuel cell cathode: a density functional theory study.

Pt-non-precious transition metals (Pt-NPTMs) alloy electrocatalysts have gained considerable attention to develop cheaper and efficient electrocatalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). In this report, density functional theory (DFT) has been applied to study the catalytic activity of Pt-skin PtV(111) electrocatalyst for ORR in PEMFCs. The results revealed that the ORR intermediates (O, OH and OOH) have lower binding energies on Pt-skin PtV(111) compared to pure Pt(111) surface. The ORR on Pt-skin PtV(111) surface proceed OOH dissociation with an activation energy of 0.33 eV. The formation of OH is found to be the rate determining step with an activation energy of 0.64 eV, which is even lower than in pure Pt(111) surface (0.72 eV). This indicates a better performance of Pt-skin PtV(111) for ORR compared to pure Pt(111) surface. Moreover, the DFT results revealed that the negative formation energy of the PtV alloy and the positive dissolution potential shift of the surface Pt atoms revealed the better stability of Pt-skin PtV(111) surface over pristine Pt(111) surface. Due to the improved activity and better stability, the new PtV alloy electrocatalyst is very promising for the development of low-cost and efficient PEMFCs.