In Silico Discovery of New Dopants for Fe-Doped Ni Oxyhydroxide (Ni_{1- x}Fe_xOOH) Catalysts for Oxygen Evolution Reaction

The oxygen evolution reaction (OER) is critical to efficient water splitting to produce the H₂ fuel for sustainable energy production. Currently, the best non-noble metal OER electrocatalyst in base conditions is the Fe-doped NiOOH (Ni_1-xFe_xOOH), with an overpotential of η = 0.4, but much lower values are desired. We use density functional theory to determine the overall mechanism for the OER of Ni_1-xFe_xOOH, concluding that promoting radical character on the metal-oxo bond is critical to efficient OER. Then we consider replacing Fe with 17 other transition metals of the Fe, Ru, and Os rows, where we find 3 new promising candidates: Co, Rh, and Ir, which we estimate to have η = 0.27, 0.15, and 0.02, respectively, all very much improved performance compared to Fe, making all three systems excellent candidates for experimental testing.