Synergy between Fe and Ni in the optimal performance of (Ni,Fe)OOH catalysts for the oxygen evolution reaction

Significance The oxygen evolution reaction (OER) is a key component to applications of electrochemistry in energy and environment, but the reaction mechanism for OER on a best-performing catalyst, the Fe-doped NiOOH [(Ni,Fe)OOH], is under debate. Using advanced quantum mechanics (QM) methods, we find that the (Ni,Fe)OOH systems feature synergy between Fe and Ni, in which the two components assume the two different key functionalities needed for OER, forming an active O radical and catalyzing the O–O coupling, respectively. It is this synergy that delivers the optimal performance of (Ni,Fe)OOH for driving the OER. This suggests a strategy to further improve the (Ni,Fe)OOH-type OER catalysts, i.e., separately screening for the best component for each key functionality.