Interfacial Oxide Engineering of TiN Antenna-Reactor for Durable Photothermal Dry Reforming of Methane.

Plasmonic TiN antenna-reactor platforms are attractive for solar dry reforming of methane, yet oxidative reconstruction of TiN in CO2-containing atmospheres undermines durability by weakening metal-support interactions and triggering nanoparticle sintering. Here, we propose a surface-oxide engineering strategy that inserts a conformal crystalline TiO2 interlayer between the TiN core and highly dispersed Ru clusters. The TiO2 interlayer stabilizes TiN, anchors subnanometric Ru clusters, and concurrently enables directional carrier delivery to Ru and photothermal heat confinement near the surface, enhancing reactant activation and product desorption while suppressing the reverse water-gas shift and coking side reactions. As a result, TiN@TiO2-Ru delivers CO and H2 formation rates of 143.9 and 92.6 mol gRu-1 h-1 under illumination, and retains 98% of its initial activity over 80 h. Mechanistic studies show that a CO2-derived, nonlattice-oxygen-mediated CH3O* pathway, in conjunction with moderated CO/C binding of Ru nanoclusters, is crucial for suppressing side reactions and sustaining long-term catalytic stability. This interfacial oxide engineering provides a general paradigm for achieving durable and efficient plasmonic photothermal catalysis.