Photon-Induced Modulation of Reaction Pathways in Ruthenium Homologous Heteroclusters with a Ruδ+-Ru0 Interface for Photothermal Dry Reforming of Methane

Abstract

Photothermal dry reforming of methane (PDRM) is a promising technology for mitigating greenhouse gas (CH4 and CO2) emissions and generating syngas under mild conditions. However, it faces challenges from the catalyst deactivation because of carbon deposition and unbalanced H2/CO ratio caused by side reactions such as reverse water–gas shift (RWGS). In this work, Ru subnanometric homologous clusters are anchored onto TiO2 to address these issues. The metallic Ru0 and oxidized Ruδ+ sites with suitable proximity are created, while the carbon layers serve as the migration channels for photon-induced electrons to Ru clusters in PDRM. This configuration enables Ruδ+ to activate CH4 while electron-enriched Ru0 sites activate CO2, facilitating direct C–O coupling of *CHx and *CO2 intermediates and reducing the reliance on lattice oxygen (OL) migration and replenishment. Consequently, the optimized catalyst delivers superior activity for H2 (416.9 mmol·g–1·h–1) and CO (344.0 mmol·g–1·h–1) production with high conversion rates of CH4 (∼60%) and CO2 (∼51%) at 540 °C. The improved H2/CO ratio and negligible deactivation in long-term stability tests are simultaneously achieved, outperforming those from thermal catalysis at the same temperature. This work provides critical insight into photon-induced reaction pathway modulation for efficient PDRM.