High Throughput Discovery of Complex Metal Oxide Electrocatalysts for the Oxygen Reduction Reaction

The oxygen reduction electrocatalysis is a key reaction for energy technologies such as fuel cells and air breathing batteries for which development of stable and efficient electrocatalysts remains a substantial challenge, especially when excluding precious metals. Multi-component metal oxides are complex materials that offer opportunities for catalyst development and challenges for prediction of optimal compositions. We use high throughput synthesis and electrochemistry to explore metal oxide electrocatalysts containing 1 to 4 of the elements Mg, Ca, Mn, Fe, Ni, Y, In, and La. Mining the resulting dataset of 7798 unique metal oxide compositions guides additional activity and stability experiments that reveal multiple avenues for further catalyst development based on (i) stabilization of Mn through incorporation in Mn-Ni–Fe oxides, (ii) discovery of Ni–Fe-La oxide electrocatalysts with excellent stability, and (iii) discovery of Mn-Ni–Fe-La oxide electrocatalysts that optimize activity while retaining excellent operational stability.