Fundamental Insights Into the Formation Mechanisms, Functional Principles, and Modulation Strategies of Charge Accumulation on Catalysts During the Oxygen Evolution Reaction

Charge accumulation has significant impacts on the activity and stability of oxygen evolution reaction (OER) catalysts, especially under high current density conditions. However, the formation mechanisms of charge accumulation and its mechanism on OER catalyst performance remain unclear. There is a lack of a mechanism for guiding the design of OER catalyst structure-performance from the perspective of regulating charge accumulation. Therefore, herein the formation mechanisms of charge accumulation in OER catalysts are revealed. Charge accumulation composition and its influence on the activity and stability of OER catalysts, as well as the corresponding boundary conditions, are systematically summarized. Based on this, directional and controllable regulation mechanisms are elucidated from the two perspectives of "charge accumulation in the low-potential range promoting OER catalyst activity" and "charge accumulation in the high-potential range undermining OER catalyst stability". Specifically, charge accumulation under low current density is promoted by increasing double-layer capacitance, deprotonation capacitance, and pseudocapacitance. Conversely, charge accumulation under high current density is suppressed through strategies such as doping, intercalation engineering, and heterojunction construction. This review provides theoretical design guidance for developing high-performance OER catalysts for industrial-scale current densities.