Regulating Electrocatalysts via Surface and Interface Engineering for Acidic Water Electrooxidation

TLDR

PEM water electrolyzers are promising for hydrogen production, yet acidic OER remains a bottleneck, and advances in surface and interface engineering—guided by theory and spectroscopy—have begun to improve catalyst activity and stability. The authors aim to critically assess the field by establishing material property–catalytic activity relationships and proposing promising research directions for high‑performance PEM catalysts. They examine prevailing acidic OER mechanisms, evaluate the role of catalyst lattice oxygen, and review experimental and theoretical advances in surface and interface engineering. They propose several promising research orientations to guide future development of high‑performance PEM catalysts.

Abstract

Although proton exchange membrane (PEM) water electrolyzers offer a promising means for generation of hydrogen fuel from solar and wind energy, in acidic environments the corresponding anodic oxygen evolution reaction (OER) remains a bottleneck. Because the activity and stability of electrocatalysts depend significantly on physicochemical properties, material surface and interface engineering can offer a practical way to boost performance. To date, significant advances have been made using a judicious combination of advanced theoretical computations and spectroscopic characterizations. To provide a critical assessment of this field, we focus on the establishment of material property–catalytic activity relationships. We start with a detailed exploration of prevailing OER mechanisms in acid solution through evaluating the role of catalyst lattice oxygen. We then critically review advances in surface and interface engineering in acidic OER electrocatalysts from both experimental and theoretical perspectives. Finally, a few promising research orientations are proposed to inspire future investigation of high-performance PEM catalysts.