Iridium-based electrocatalysts for alkaline hydrogen oxidation reaction

The utilization of renewable energy conversion devices is regarded as a viable approach to mitigate both the scarcity of energy resources and their detrimental impact on the environment. Consequently, the investigation of clean and sustainable energy sources possessing a high gravimetric energy density has served as a significant impetus for exploring hydrogen energy as a cost-effective substitute for fossil energy. Accelerating the reaction process and applying it on a larger scale both stand to benefit from the development of electrocatalysts that offer high levels of performance at reasonable prices. The development of efficient and cost-effective electrocatalysts for hydrogen oxidation reaction (HOR) is crucial for advancing the field of hydrogen fuel cells. Compared to commercial platinum catalyst (Pt/C), iridium-based (Ir-based) nanomaterials have demonstrated catalytic performance that is on par with Pt/C. This review firstly summarizes the recent progress of Ir-based catalysts and the electrocatalytic performance towards HOR. Then, the challenges and prospects are highlighted, which lie ahead for the future development and practical application of Ir-based nanomaterials. Further research to optimize the catalytic performance, reduce the catalyst loading, and cost, and understand the mechanism is emphasized. The findings could pave the way for developing advanced HOR electrocatalysts, accelerating the realization of efficient and sustainable hydrogen-based energy systems.