Oxide Electrocatalysts Based on Earth-Abundant Metals for Both Hydrogen- and Oxygen-Evolution Reactions
Ram Krishna Hona, Surendra B. Karki, Farshid Ramezanipour
Abstract
A unique bifunctional oxide electrocatalyst capable of catalyzing both half-reactions of water splitting, namely, oxygen-evolution reaction (OER) and hydrogen-evolution reaction (HER), with the added capability of catalyzing HER in both acidic and basic media, a rare property in water-splitting catalysts, is reported. In addition to the bifunctional electrocatalytic properties, CaSrFeMnO6−δ shows OER activity, which is even superior to the reported activities of precious-metal electrocatalysts, IrO2 and RuO2. The correlation of electrocatalysis with the charge-transport properties in the series Ca2FeMnO6−δ, CaSrFeMnO6−δ, and Sr2FeMnO6−δ is demonstrated. Given the dependence of charge transport on structure and defects, this work unravels the interesting correlations between the triangle of structure, charge transport, and electrocatalytic activity for water splitting.