ABSTRACT
The large-scale production of green hydrogen by proton exchange membrane (PEM) water electrolysis is currently of considerable interest. However, oxygen evolution reaction (OER) occurring in the anode is a primary source of overpotential due to the sluggish kinetics. To realize fast reaction kinetics, it is essential to obtain a facile electron transfer between electrocatalysts and the oxygen intermediates, which is critically related to reaction mechanism and electrode interface. Meanwhile, developing high-performance electrocatalysts for acidic OER is an outstanding challenge since most metal materials are unstable under the strong acidic and oxidative conditions. Even for the promising electrocatalyst candidates, Ir oxides undergo the continuous Ir dissolution due to surface oxidization during OER [1,2]. It is also difficult to establish the structure–performance relationship due to the dynamic changes of catalyst surface (named surface reconstruction). Hence, acquiring an enhanced understanding of the electron transfer pathways and reaction interface is crucial for the design of efficient and robust OER electrocatalysts.
