The research progress of single-atom catalysts for the hydrogen evolution reaction

Hydrogen, a clean and renewable energy source, stands as a promising alternative to fossil fuels. Electro-catalytic water splitting has gained significant attention for hydrogen production due to its simplicity and ability to generate high-purity H₂. The efficiency of this process hinges on the performance of electrocatalysts, underscoring the need for cost-effective, highly efficient, and durable materials to drive the hydrogen evolution reaction (HER). In recent years, single-atom catalysts (SACs) have revolutionized the field of catalysis, offering unparalleled activity and maximizing atomic utilization. This review delves into the mechanisms of HER and highlights recent breakthroughs in SACs, particularly those based on Pt and non-noble metals such as Fe, Ni, and Co. It also examines advanced characterization and simulation techniques essential for understanding SACs, while exploring design strategies like heteroatom doping, defect engineering, and coordination environment tuning to enhance performance. Finally, the review addresses key challenges in applying SACs for HER and proposes solutions to advance this transformative technology.