Research on Cu-based and Pt-based catalysts for hydrogen production through methanol steam reforming

Methanol steam reforming (MSR) is a critical pathway for on-board hydrogen production from methanol, playing a significant role in clean energy applications. The catalytic performance in MSR reactions directly influences hydrogen yield and byproduct composition, with Cu-based and Pt-based catalysts extensively studied for their high efficiency. The catalytic mechanism primarily involves the cleavage of C–H and O–H bonds in methanol and water molecules. The activity of Cu-based catalysts depends on the ratio and synergistic interaction of Cu⁰ and Cu⁺ ​active sites, while Pt-based catalysts operate through Pt⁰, Pt^δ+ or Pt²⁺ active sites, in conjunction with oxygen vacancies. However, the electron transfer and interaction mechanisms between active metals and supports remain contentious, impacting the metal oxidation states, adsorption sites, and reaction pathway selectivity. This is particularly evident in the pathways for methanol dehydrogenation and intermediate product formation (e.g., formaldehyde, formic acid, and methyl formate), which lack a unified understanding. This review systematically examines the unitary and synergistic roles of Cu⁰ and Cu⁺ ​sites, explores the direct and synergistic pathways of Pt-based catalysts, and analyzes the effects of additives such as In₂O₃ on Pt site modulation and oxygen vacancy generation. By integrating catalytic performance evaluations with mechanistic insights, strategies are proposed to enhance catalyst activity and stability. This comprehensive review not only advances the understanding of MSR mechanisms but also provides a theoretical foundation and research direction for the development of high-performance catalysts for on-board hydrogen production.