Advances in defect-engineered metal-support interactions for acidic oxygen evolution reaction

The development of efficient and stable catalysts for the acidic oxygen evolution reaction (OER) is critical for the commercialization of proton exchange membrane water electrolyzers (PEMWEs). To reduce the reliance on scarce noble metals, a common strategy is to anchor them onto stable supports, where fine-tuning the metal-support interaction (MSI) is crucial for balancing activity and durability. Particularly, defects of the support material (e.g. vacancies, grain boundaries etc.) have proven highly effective for modulating MSI, as they can tailor the coordination environment of metal sites and significantly enhance stability by suppressing metal dissolution. This review comprehensively summarizes the controllable synthesis strategies of defective supports and discusses the latest advances in understanding the metal-defect interactions for the acidic OER. More importantly, it also highlights the application of state-of-the-art in situ/operando characterization techniques and theoretical computations to elucidate these critical interface effects and dynamic reaction mechanisms. Finally, it discusses the challenges and prospects of development in this field, aiming to inspire the design of efficient, highly stable catalysts for the acidic OER.