Critical Role of Carbon Substrates in Optimizing Ru‐Based HER Catalysts: From Dimensional Insights to Metal‐Support Interactions Engineering

Abstract The development of cost‐effective and high‐performance electrocatalysts for the hydrogen evolution reaction (HER) is essential for sustainable hydrogen production through water splitting. Carbon‐supported ruthenium (Ru)‐based catalysts have emerged as a promising alternative to platinum‐based systems due to their exceptional HER activity and stability, positioning them at the forefront of current research. Notably, the carbon substrate plays a critical role in optimizing the performance of Ru‐based catalysts. This review comprehensively summarizes recent advances in carbon‐supported Ru‐based HER catalysts, starting with their fundamental characteristics. Significantly, the analysis uniquely focuses on dimensional effects of carbon substrates (0D, 1D, 2D, and 3D) on metal‐support interactions (MSIs), thereby distinguishing this work from existing reviews. Furthermore, various effective strategies for enhancing MSIs between Ru species and carbon substrates, such as heterogeneous atom doping, single‐atom engineering, vacancy engineering, and heterostructure engineering, are presented. Finally, the challenges and future directions associated with carbon‐supported Ru‐based HER catalysts are discussed. This comprehensive review aims to provide fundamental insights into carbon‐supported Ru‐based catalysts, elucidate MSI enhancement pathways, and inspire the design of next‐generation HER electrocatalysts for sustainable energy conversion.