Advances in Cu-based catalysts for methanol steam reforming: Mechanistic insights and atomic-level design

Methanol steam reforming (MSR) represents a promising route for hydrogen production, leveraging the high energy density and liquid-phase storage advantages of methanol. Copper-based catalysts have become indispensable for MSR due to their cost-effectiveness, exceptional catalytic activity, and tunable selectivity. However, persistent challenges such as thermal sintering, undesirable CO byproduct formation, diminished low-temperature reactivity, and long-term catalyst deactivation limit their broad industrial deployment. This review comprehensively examines the mechanistic pathways of MSR over Cu-based catalysts, with particular focus on differentiating catalyst formulations optimized for high-temperature (>200 °C) versus low-temperature (<200 °C) operation. It highlights the decisive influence of Cu nanoparticle size, electronic structure, and crystal structure on catalytic performance. Cutting-edge design strategies, including multi-element engineering, innovative synthesis techniques, and deactivation mitigation, are critically evaluated to elucidate mechanistic connections between atomic-scale structure and catalytic performance enhancement. Finally, industrial applications of commercial Cu/ZnO/Al₂O₃ variants and their scalability challenges are discussed, alongside prospective strategies for catalyst innovation and engineering to advance next-generation hydrogen production.