Dynamic distance modulation and active site separation in Ru1-Ru3@MoS2 catalyst for C-O bond activation

Abstract

Current strategies for C-O bond activation primarily rely on static single-site catalysts, which often suffer from steric congestion and limited catalytic efficiency. In this work, we report a dynamic synergistic catalyst, Ru₁-Ru₃@MoS₂, consisting of coplanarseparated Ru₁ single atom and Ru₃ cluster anchored on a defective MoS₂ substrate. For phenol hydrodeoxygenation, this dual-site system achieves a very low C-O bond cleavage barrier of 0.85 eV. Mechanistic investigations reveal a dynamic wave-like evolution of the inter-site distance (4.94→4.14→4.84 Å), which drives the phenyl group to migrate toward the Ru₃ cluster while the hydroxyl group remains anchored at the Ru₁ site. This arrangement enables spatially separated active sites and sequential tandem catalysis. The activation process is further governed by Ru-d_xz/O-p_z orbital hybridization and electron transfer mediated by bridging sulfur atoms. This dynamic structure-activity relationship offers a new design paradigm for developing highperformance catalysts for biomass conversion.