Unveiling structure-performance relationships in HER catalysts for sustainable and scalable hydrogen production

The hydrogen evolution reaction (HER) is a crucial electrochemical process for producing clean hydrogen, providing a sustainable pathway to decarbonize energy systems and mitigate the impacts of climate change. Designing next-generation HER electrocatalysts with high activity, durability, and scalability relies on a fundamental understanding of how atomic structure, surface defects, and interfacial properties govern catalytic performance. Recent advances in tailored synthesis, in situ and operando characterization, and comprehensive electrochemical evaluation have provided deeper insights into catalyst behavior under realistic conditions. In parallel, theoretical tools such as density functional theory, machine learning, and multiscale modeling have accelerated the discovery of active sites, reaction pathways, and structure-property relationships. This review critically examines these developments across a wide range of materials, including noble metals, transition metal compounds, carbon-based systems, and single-atom catalysts, highlighting sustainable design strategies for resource efficiency and reduced environmental impact. By bridging atomic-scale insights with practical implementation, this work outlines key challenges and opportunities to guide the development of HER electrocatalysts that support green hydrogen production and contribute directly to sustainable energy systems. The perspective presented aims to inspire materials scientists, engineers, and policymakers to advance hydrogen technologies that align with global sustainability goals.