Catalysis Meets Spintronics, Spin Potentials Associated with Open-Shell Orbital Configurations Enhance the Activity of Pt3Co Nanostructures for Oxygen Reduction: A Density Functional Theory Study

One of the main obstacles in the implementations of hydrogen fuel cells (HFC) lies in the efficiency loss due to the overpotential of the oxygen reduction reaction (ORR). Nowadays, the best catalysts for cathodes in HFC are Pt3Co nanostructures. The superior activity of these magnetic Pt-alloys, compared to metallic platinum, correlates with the milder chemisorption of the oxygenated intermediates on the surfaces of the alloy. Quantum Spin Exchange Interactions (QSEI), including minor interlayer exchange coupling due to magnetic inner Co layers, are determinant to make the active sites prone to bind adsorbed oxygen atoms in an optimal fashion for catalytic activity. We present a study on antiferromagnetic (AFM) and ferromagnetic (FM) Pt3Co (111) nanostructures conducted via spin-polarized DFT+U calculations. The study begins with a thorough screening of AFM, FM and fictitious closed-shell Pt3Co slab models with different atomic distribution ranked in order of stability. The chemisorption enthalpy of O* an...