High-efficient sunlight-driven hydrogen production from methanol steam reforming on a novel photo-thermo-catalysis and thermo-catalysis dual-bed reactor

Sunlight-driven methanol-steam-reforming (MSR) reaction using solar energy promises efficient production and safe transportation of hydrogen energy while storing solar energy. However, the low efficiency of photo-reforming and the high cost of thermo-reforming, intrinsically due to limited usage of full-spectrum solar energy, pose a significant challenge to practical application. Here, we propose a sunlight-driven dual-bed photo-thermo-catalytic reactor (DBPTR) for high-efficient hydrogen production from MSR with the cascaded utilization of photo-thermo-catalysis (PTC) over Pt-CuO catalyst bed and thermo-catalysis (TC) over CuO/ZnO/Al₂O₃ catalyst bed, respectively. The experimental data verify that the overall solar-to-hydrogen (STH) efficiencies of DBPTR remarkably achieve 22.5% in the laboratory and 20.3% outdoors, respectively. These excellent performances are evidently attributed to the fact that our DBPTR could harvest the short-wave radiation (high-energy photons) in the PTC bed for photo-thermo-driven hydrogen production and confine the long-wave radiation (low-energy photons) in the TC bed for thermo-driven hydrogen production. Meanwhile, the proposed DBPTR has been proved to be scaled-up and operate under a reasonably concentrated irradiance of 16 kW m⁻² with the above high STH efficiency, harmonizing the high-performance reactor, low-cost concentrator and moderate-accuracy sun-tracker. This work opens up a novel practical pathway towards high-efficient solar-to-chemical conversion.