The reaction mechanism of acetylene hydrochlorination on defective carbon supported ruthenium catalysts identified by DFT calculations and experimental approaches

Abstract

It is critical to identify the reaction mechanism of carbon supported metal catalysts for the exploration of high-performance catalysts in acetylene hydrochlorination. Herein, we reported a systematic study on the role of defective carbon for ruthenium catalysts in acetylene hydrochlorination via density functional theory calculations and experimental methods. The single vacancy sites on the surface of defective carbon form strong chemical bonds with ruthenium chloride and increase the electron density of ruthenium ions in the ruthenium catalyst. The deactivation rate of ruthenium catalysts in acetylene hydrochlorination is approximately linearly related to their acidity and coke deposition. Further studies on the reaction mechanism show that the reaction barrier of the defective carbon supported ruthenium chloride with high electron density is reduced, and the polymerization of acetylene and vinyl chloride, which is the side reaction of acetylene hydrochlorination, is significantly inhibited. Thus, the defective carbon supported ruthenium catalyst shows high catalytic activity and stability. This work contributes to understanding the effect of the electron density of the catalyst on the main and side reactions and the rational design of catalysts for acetylene hydrochlorination.