Ternary Schottky-p-n heterojunction strategy for enhancing photothermal dry reforming of methane

Abstract

Breaking the trade-off between activity and stability in catalysts for dry reforming of methane has long remained a huge challenge. Here, we demonstrate a ternary Schottky-p-n (TSPN) heterojunction strategy based on Ni-NiO-Sr₂Nb₂O₇ (NiO_x/SNO) for photothermal dry reforming of methane. This approach achieves a stable syngas production rate of 10.54 moles per gram per hour, with a light-to-fuel efficiency of 28.3% and a CH₄ turnover frequency of 18 per second at 500°C generated by concentrated light irradiation. This low-temperature, high-rate activity benefits from the photoaccelerated CH₄-to-H₂ process facilitated by the synergistic effect of NiO and Ni⁰. Furthermore, the light-induced spatial separation of dual reduction sites for CO₂ reduction (SNO) and H₂ evolution (Ni⁰) suppresses the reverse water-gas shift (RWGS) reaction, ensuring continuous supply of active oxygen and improving reaction stability. This finding is expected to substantially promote low-temperature photothermal catalytic technology in enhancing the selective conversion efficiency of C₁ molecules.