Recent research progress on Ruthenium-based catalysts for electrocatalytic water splitting

• Summarizing Ru-based electrocatalyst’ applications in HER, OER and overall water splitting. • Classifying and elucidating the catalytic mechanisms of distinct Ru-based electrocatalyst types. • Analyzing core practical application challenges of Ru-based electrocatalyst. • Proposing targeted strategies for stability, mechanism and industry. Ruthenium (Ru), leveraging their unique electronic structures, have shown tremendous potential in balancing catalytic activity and cost, emerging as a hotspot for electrocatalytic water splitting. In this review, we systematically analyzes the mechanism, advantages, and latest research breakthroughs of Ru-based catalysts. The high intrinsic activity originates from the moderate of hydrogen adsorption and excellent oxygen evolution activity endowed by the variable valence states. To fully unlock Ru potential, research strategies have shifted from macroscale synthesis to atomic-level precise regulation, such as structure modulation, element doping, single-atomization, and composite materials have been developed to significantly enhance its catalytic activity and structural stability. Particularly, based on Ru’s bifunctional properties, the efficient overall water splitting catalysts such as phosphides, sulfides, and various composite materials have been successfully developed. Despite significant achievements, Ru-based catalysts still face challenges in stability, activity enhancement, and large-scale synthesis. Future research will focus on deepening mechanism elucidation, designing new materials with ultra-high performance, and advancing the development toward scalable electrodes. Ru-based catalysts are expected to become one of the key materials driving the realization of hydrogen economy.