Harnessing light to facilitate methanol conversion for high-efficiency hydrogen production under mild conditions

Abstract

For hydrogen storage applications, methanol serves as an ideal medium that effectively addresses storage and transportation challenges based on methanol steam reforming (MSR), which requires high temperatures (＞ 250 °C). Metal nanoparticles (e.g., Cu) with a localized surface plasmon resonance (LSPR) effect can utilize light to generate hot carriers for chemical reactions. Herein, the as-prepared Ga-doped CuZn catalyst (CuZn10Ga) achieves an exceptional H₂ production rate of 243.1 ± 4.7 mmol·g⁻¹·h⁻¹ with near-perfect CO₂ selectivity (99.9 %) and negligible CO selectivity (0.1 %), while maintaining excellent stability over 150 h under mild conditions (190 °C, 500 mW·cm⁻²). Detailed experimental studies reveal that Ga induced strong metal-support interactions (SMSI) in the CuZn10Ga, creating a high density of Cu-ZnO_x interfacial active sites. Under photo-thermal conditions (190 °C, 500 mW·cm⁻²), light enhances both methoxy (*OCH₃) conversion and formate (*HCOO) decomposition efficiency, as verified by catalytic experiments and in situ DRIFTS. This work offers valuable insights into the precise design of noble-metal-free active sites and the development of low-temperature activation technologies.