Emerging noble-metal-free catalysts for hydrogen technologies: Bridging theory and practice

Noble-metal-free catalysts are emerging as cost-effective, durable, and scalable alternatives to platinum-group metals (PGMs). This review surveys advances across four domains: computation, production, storage, and conversion. Computational methods, including density functional theory and machine learning, accelerate discovery by predicting adsorption energetics, identifying active sites, and guiding operando characterization. In hydrogen production, carbon materials, transition-metal oxides, phosphides, and single-atom frameworks enable efficient thermocatalytic, electrocatalytic, and photocatalytic processes, narrowing the gap with PGMs. In hydrogen storage, porous adsorbents, solid-state hydrides, and liquid organic hydrogen carriers are re-engineered with earth-abundant catalysts to improve kinetics, reversibility, and durability. In hydrogen conversion, heteroatom-doped carbons, transition-metal alloys, and M–N–C single-atom catalysts show competitive activity for the oxygen reduction and hydrogen oxidation reactions. Hybrid systems that combine trace PGMs with non-precious elements offer pragmatic pathways to commercialization. By integrating theoretical insight with experimental validation, these studies establish design principles that link electronic structure, microstructure, and performance. The target audience includes researchers and practitioners in catalysis, materials science, and energy engineering. This review provides a framework for translating noble-metal-free catalysts into scalable hydrogen technologies and reinforces hydrogen’s role as a cornerstone of the global energy transition.