Densely-neighbored-Ru nanoparticles confined in porous-SiO₂ shell for efficient CO₂ methanation via...

Plasmonic metal nanostructures hold immense promise for catalysis, yet their potential remains limited by inefficient utilization of plasmon-derived energy. Herein, guided by theoretical predictions on the merits of plasmon-coupling metal nanoparticles within dielectric matrices, Ru_m@pSiO₂ nanoreactors, where clustered Ru nanoparticles confined in a porous SiO₂ shell, are rationally designed. This architecture features enhanced plasmon-energy harvesting, intensified electromagnetic field confinement, and optimized photothermal management. Consequently, the as-designed Ru_m@pSiO₂-2 nanoreactor achieved a remarkable CH₄ production rate of 8.75 mol g_Ru^-1 h^-1 with near-100% selectivity at 250 °C under irradiation in photo-thermal CO₂ methanation, surpassing surface-supported Ru_m/pSiO₂ and isolated Ru₁@pSiO₂ catalysts by 3.2- and 2.6-fold, respectively. Notably, it delivered a CH₄ yield of 2.26 L g_cat^-1 h^-1 under natural sunlight, even on a winter day (outdoor temperature: -4-6 °C). This study provides a comprehensive understanding on plasmonic energy utilization for photo-thermal catalysis and establishes a groundbreaking design paradigm for next-generation photothermal catalysts.