Design Strategies of Active and Stable Oxygen Evolution Catalysts for Proton Exchange Membrane Water Electrolysis

Proton exchange membrane water electrolyzers (PEMWEs) hold great promise for the efficient production of clean hydrogen, which is vital for the transition of the current hydrocarbon-based energy infrastructure to a sustainable, circular energy future. The efficiency of a PEMWE relies heavily on the performance of the oxygen evolution reaction (OER) at the anode. Accordingly, the development of highly active and stable OER catalysts under acidic conditions is crucial for the practical implementation of PEMWEs. Herein, we present recent advances in efficient acidic OER catalysts, focusing on their rational design and in situ characterization. We illustrate representative synthetic strategies that can boost the intrinsic activity, extrinsic activity, and stability of acidic OER catalysts. Next, we discuss state-of-the-art in situ characterization techniques that enable the identification of active catalytic sites and an understanding of the OER pathways. Finally, we summarize the OER activities of high-performance catalysts in half- and single-cell configurations, providing meaningful insights into bridging the gap between the laboratory-scale development of a new catalyst and its device-level implementation for PEMWEs.