Work

Plasmon‐Enhanced CO 2 Methanation over Au@Ru/TiO 2 via Nanoscale Control of Ru Shell Thickness

Year: 2025

Type: article

Abstract: Plasmonic‐catalytic nanostructures enable coupling light harvesting with chemical transformations, yet their performance critically depends on nanoscale architecture and metal‐support interactions. Here, we synthesize Au@Ru core–shell nanoparticles with tunable Ru coverage and immobilize them on TiO 2 to create hybrid catalysts for CO 2 methanation. By controlling Ru shell thickness, we identifyAu 60 Ru 40 /TiO 2 , featuring a thin, discontinuous shell (∼2 nm Ru nanocrystallites), as the most active composition. This catalyst combines abundant Ru active sites with preservation of the Au core's localized surface plasmon resonance (LSPR). Under 545 nm illumination, it shows a 335% rate enhancement over dark conditions at 190 °C, outperforming commercial Ru/C and remaining stable for 85 h. Optical, structural, and kinetic analysis indicate that illumination accelerates the methanation without changing the rate‐determining step, consistent with a dominant photothermal contribution. Density functional theory reveals that TiO 2 induces strong metal‐support interactions, upshifts the Ru d‐band center, strengthens CO 2 adsorption, and lowers the barrier for the first hydrogenation step, shifting the rate‐limiting step to CH 4 desorption. These results establish Au@Ru/TiO 2 as an efficient platform for visible‐light‐assisted thermocatalysis and demonstrates that nanoscale shell engineering as a generalizable strategy to optimize plasmonic catalysts for CO 2 hydrogenation and beyond.

Source: Angewandte Chemie International Edition

DOI: 10.1002/anie.202518748