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/CeZrO_x 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 Cu^{δ +}-O_v-CeZrO_x 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*⇋O_v]-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.