A Phosphorus-Modified Ultralow Content Ru Catalyst for Acetylene Hydrochlorination

Reducing the noble metal loading while maintaining its high catalytic performance is a challenge. Herein, we engineer Ru/C-P═O synergistic sites to develop an ultralow-content Ru catalyst. The Ru content is as low as 0.05%. The 0.05% Ru/P7AC catalyst exhibits an excellent acetylene conversion of 94% in the acetylene hydrochlorination under conditions of 180 °C and a GHSV(C₂H₂) of 60 h^-1. Such a low Ru content and high catalytic performance can be attributed to the Ru/C-P═O species on P-doped carbon. The synergistic interaction between Ru and C-P═O species promotes the dispersion of Ru species, increases the content of high valence Ru, and enhances the adsorption of acetylene, thereby improving the catalyst activity. Simultaneously, the synergistic interaction between Ru and C-P═O species also slows the reduction of high valence Ru and inhibits coke deposition, thereby enhancing the catalyst stability. DFT calculations further validate the synergistic interaction of Ru and C-P═O species, and a novel reaction pathway involving the C-P═O species is proposed. This work develops ultralow-content Ru catalysts with high catalytic activity, offering a viable strategy for designing mercury-free catalysts.