Photo-Promoted Thermocatalysis: Low-Temperature Methanol Steam Reforming Toward Hydrogen Production.

Methanol steam reforming (MSR) is an important route for on-site H2 production, yet practical application is generally constrained by high operation temperature and substantial energy consumption. Photothermal catalysis, in which hot electrons participate in catalytic reaction, offers a promising pathway for low-temperature MSR. Herein, a Cu/CeZrOx photothermal catalyst (denoted as CuCZ) was prepared through a coprecipitation-calcination-reduction strategy. The optimized CuCZ achieves a hydrogen production rate of 180.9 µmol g-1 s-1 under full-spectrum irradiation at 199°C, which is 26.2 times larger than that obtained with thermocatalytic mode, while maintaining a CO selectivity below 0.2%. A comprehensive structural characterization reveals the formation of Cuδ +-Ov-CeZrOx interfacial sites with pronounced light-induced interfacial reconstruction. In situ spectroscopic studies, kinetic analyses, and density functional theory calculations substantiate a photo-assisted thermocatalytic mechanism, in which photoexcitation drives hot electron injection and interfacial electron transfer, triggering a dynamic evolution of the Cu0/Cu+-[O*⇋Ov]-Ce3+/Ce4+ interfacial structure. This dynamic interface enables the synergistic coupling of methanol dissociation, H2O activation, and lattice oxygen regeneration, which boosts the kinetically relevant step (HCOO* conversion) by five times and delivers a 21.8% reduction in the kinetic isotope effect. This photo-assisted thermocatalysis overcomes the inherent kinetic limitations of low-temperature MSR, accounting for significantly promoted reaction efficiency.