High-efficient solar-driven hydrogen production by full-spectrum synergistic photo-thermo-catalytic methanol steam reforming with in-situ photoreduced Pt-CuO_x catalyst

Synergy between the intrinsic photon and thermal effects from full-spectrum sunlight for H₂ production is considered to be central to further improve solar-driven H₂ production. To that end, the photo-thermo-catalyst that demonstrates both photoelectronic and photothermal conversion capabilities have drawn much attention recently. Here, we propose a novel synergistic full-spectrum photo-thermo-catalysis technique for high-efficient H₂ production by solar-driven methanol steam reforming (MSR), along with the Pt-CuO_x photo-thermo-catalyst featuring Pt-Cu/Cu₂O/CuO heterojunctions by Pt-mediated in-situ photoreduction of CuO. The results show that the H₂ production performance rises superlinearly with increasing light intensity. The optimal H₂ production rate of 1.6 mol g⁻¹ h⁻¹ with the corresponding solar-to-hydrogen conversion efficiency of 7% and the CO selectivity of 5% is achieved under 15 × sun full-spectrum irradiance (1 × sun = 1 kW m⁻²) at 180 °C, which is much more efficient than the previously-reported Cu-based thermo-catalysts for MSR normally operating at 250∼350 °C. These attractive performances result from the optimized reaction kinetics in terms of intensified intermediate adsorption and accelerated carrier transfer by long-wave photothermal effect, and reduced activation barrier by short-wave photoelectronic effect, due to the broadened full-spectrum absorbability of catalyst. This work has brought us into the innovative technology of full-spectrum synergistic photo-thermo-catalysis, which is envisioned to expand the application fields of high-efficient solar fuel production.