From alkali promotion to mechanistic understanding: enabling stable and efficient hydrogen production from methanol-water reforming over Cu@C

Aqueous phase reforming of methanol (APRM) provides a promising strategy for in-situ hydrogen production, yet its practical application is hindered by insufficient catalyst activity and stability. Herein, we report a carbon-coated copper catalyst with uniformly dispersed nanoparticles for efficient APRM. The Cu@C catalyst exhibits significantly enhanced performance in the presence of KOH, achieving an average hydrogen productivity of 236.2 μmol H2 /g cat. /s at 220 °C, nearly triple that under alkali-free conditions. Notably, the hydrogen purity reaches 99.99% with negligible CO x and alkane byproducts. Mechanistic studies reveal that methanol reforming proceeds via the methyl formate pathway, while KOH promotes reaction efficiency mainly by in-situ CO 2 capture to form KHCO 3 and by removing poisonous CO species. The synergy between Cu@C and KOH boosts catalytic activity, ensures high-purity hydrogen production, and offers a viable approach for stable and scalable APRM-based hydrogen generation.