Dual-Atom Catalysts for Hydrogen Evolution: Electronic Structure Insights and Synthesis Strategies

The hydrogen evolution reaction (HER) serves as the cornerstone of electrochemical water splitting, providing a sustainable route for high-purity hydrogen generation and underpinning the development of a carbon-neutral energy economy. Despite the remarkable intrinsic activity of platinum-based catalysts, stemming from their ideal hydrogen adsorption energy and superior kinetics, their scarcity and high cost present formidable obstacles to scalable and economically viable hydrogen production. Dual-atom catalysts (DACs) have recently emerged as promising alternatives owing to their unique synergistic effect between adjacent metal sites, nearly 100% atomic utilization, and tunable adsorption energy of intermediates through dynamic coordination. This review begins by summarizing recent progress in DACs for HER and outlining their main structural categories. It then discusses the intrinsic advantages and underlying origins of DACs in hydrogen evolution, with particular emphasis on electronic structure modulation strategies, including tuning metal compositions, coordination environments, and geometric configurations to optimize catalytic performance and enhance catalyst stability. The discussion is further extended to the dynamic evolution of DACs under reaction conditions and the associated challenges. Furthermore, representative synthesis approaches, including high-temperature pyrolysis, atomic deposition, and immersion methods, are highlighted. Finally, current challenges and future perspectives for advancing DAC-based HER catalysis are proposed.