Plasmon‐Enhanced CO <sub>2</sub> Methanation over Au@Ru/TiO <sub>2</sub> via Nanoscale Control of Ru Shell Thickness
Abstract
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.
Article Details
Authors (11)
Florian Rathmann
VTT Technical Research Centre of Finland P O Box 1000 Espoo FIN‐02044 Finland
IbrahiM Abdelsalam
Department of Chemistry University of Helsinki A.I. Virtasen aukio 1 PO Box 55 Helsinki FIN‐0014 Finland
Shiqi Wang
Maja M. Kubik
Department of Chemistry University of Helsinki A.I. Virtasen aukio 1 PO Box 55 Helsinki FIN‐0014 Finland
Sana Frindy
Department of Chemistry University of Helsinki A.I. Virtasen aukio 1 PO Box 55 Helsinki FIN‐0014 Finland
Tiago V. Alves
Departamento de Físico‐Química Instituto de Química Universidade Federal da Bahia Rua Barão de Jeremoabo, 147 Salvador Bahia 40170‐115 Brazil
Mykhailo Chundak
Department of Chemistry University of Helsinki A.I. Virtasen aukio 1 PO Box 55 Helsinki FIN‐0014 Finland
Mikko Ritala
Department of Chemistry University of Helsinki A.I. Virtasen aukio 1 PO Box 55 Helsinki FIN‐0014 Finland
Alexander Reznichenko
VTT Technical Research Centre of Finland P O Box 1000 Espoo FIN‐02044 Finland
Matti Reinikainen
VTT Technical Research Centre of Finland P O Box 1000 Espoo FIN‐02044 Finland
Pedro H. C. Camargo
Department of Chemistry University of Helsinki A.I. Virtasen aukio 1 PO Box 55 Helsinki FIN‐0014 Finland