Fully Exposed Cu Clusters with Ru Single Atoms Synergy for High-Performance Acetylene Semihydrogenation

Semihydrogenation of acetylene is an essential process in the ethylene industry for removing acetylene impurities and ensuring the production of polymer-grade ethylene. Atomically dispersed Cu catalysts have attracted significant attention due to their cost-effectiveness and catalytic potential. However, the inherently weak hydrogen dissociation ability of Cu results in low catalytic activity, necessitating elevated reaction temperatures, which limit its practical applicability. To overcome this limitation, we design a Ru single-atom-decorated, fully exposed Cu cluster catalyst (Ru₁Cu_n/SiO₂) that exhibits outstanding performance in semihydrogenation of acetylene, achieving 100% acetylene conversion with 98% ethylene selectivity at 170 °C. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), X-ray absorption spectroscopy (XAS), and X-ray photoelectron spectroscopy (XPS) confirm the atomic dispersion of Ru and the structural evolution of Cu clusters. H₂-D₂ exchange and temperature-programmed desorption (TPD) experiments reveal that Ru modification significantly enhances the hydrogen dissociation ability of the catalyst while tuning acetylene adsorption. Density functional theory (DFT) calculations further demonstrate that the Ru single atoms and Cu nanoclusters create a synergistic catalytic interface that markedly promotes hydrogen activation and lowers the energy barrier of the rate-determining step. This study provides fundamental insights into the rational design of atomically dispersed bimetallic catalysts and offers a new strategy for the efficient and selective acetylene hydrogenation.