A review of efficient electrocatalysts for the oxygen evolution reaction at large current density

Within the framework of achieving global carbon neutrality, utilizing electrocatalytic water splitting to produce "green hydrogen" holds significant promise as an effective solution. The strategic development of economic, efficient, and robust anode oxygen evolution reaction (OER) catalysts is one of the imminent bottlenecks for scalable application of electrolyzing water into hydrogen and oxygen, particularly under actual yet harsh operating conditions such as large current density (LCD). In this review, we intend to summarize the advances and challenges in the understanding of the electrocatalytic OER at LCD. Initially, the impact of LCD on the electron transfer, mass transportation efficiency and catalyst stability is identified and summarized. Furthermore, five basic principles for catalyst design, namely the dimension of the materials, surface chemistry, creation of electron transfer pathways, synergy among nano-, micro-, and macroscale structures, and catalyst-support interaction, are systematically discussed. Specifically, the correlation between the synergistic function of the multiscale structures and the catalyst-support interaction is highlighted to direct improvements in catalyst efficiency and durability at the LCD. Finally, an outlook is prospected to further our understanding of these topics and provide related researchers with potential research areas.