Constructing MgAlOx–CuRu–CeO2 Heterostructures for Enhanced Low-temperature Photothermal Dry Reforming of Methane

Light-driven photothermal methane dry reforming offers a promising strategy to produce syngas efficiently with decreased greenhouse gas emissions. However, current photothermal catalysts still face limitations in light-to-fuel efficiencies, typically below 30%. Herein, a MgAlOx–CuRu–CeO2 heterostructure was successfully constructed to boost the light-driven methane dry reforming reaction, which integrated plasmonic resonance, electronic structure modulation, and hierarchical architectures. A remarkable CO production rate of 215.4 mol gRu–1 min–1 was achieved, approximately 18 times higher than that of current advanced catalysts. Moreover, a record-high light-to-fuel efficiency of 42.5% was obtained at a relatively low temperature of 502 °C, along with an exceptionally stable photothermal performance over 60 h of operation. Structural evolution studies revealed that CuRu bimetallic nanoparticles were thermally stabilized via spatial confinement mediated by MgAlOx, which established balanced metal–support interactions and generated abundant oxygen vacancies. Additionally, the multifunctional architecture enhanced electron transfer and created electron-enriched Ru sites. The surface plasmon resonance effect of Cu and oxygen defects within the MgAlOx–CuRu–CeO2 heterostructure enabled wide-bandwidth light harvesting and promoted the formation and segregation of charge carriers. Hot carriers and thermal energy synergistically refined the reaction pathway through HCOO* and CH3O* intermediates, leading to a decrease in the apparent activation energy and enabling the surpassing of thermodynamic equilibrium limitations. This work highlights a promising strategy for boosting solar energy utilization and driving the efficient synthesis of solar fuels through the strategic engineering of multifunctional photothermal catalysts.