Enhanced catalytic performance of activated carbon-supported Ru-based catalysts for acetylene hydrochlorination by azole ligands

Abstract Supported Ru-Lx/AC catalysts were synthesised by coordinating a Ru precursor with several azole ligands and assessed for acetylene hydrochlorination. The results demonstrated that the coordinated Ru-imidazole/AC (Ru-L1/AC) catalyst exhibited superior catalytic activity compared to that of catalysts coordinated with other ligands. In addition, the substitution of hydrogen on the imidazole ring by electron-donating substituents further improved the catalytic performance. Specifically, the coordination between the ruthenium precursor and heteroatom in the ligands, which contain a conjugated structure and an electron-donating substituent, promoted the transfer of electrons from the heteroatom to Ru cation and augmented the electron cloud density around the active centres, which helps stabilise high-valence Ru and produce more active Run+ species. In addition, the coordination contributed to the anchoring and dispersion of active species, which improved the catalytic hydrochlorination of acetylene. Thus, the as-designed Ru-1-isopropyl imidazole/AC (Ru-L8/AC) catalyst exhibits a superior performance and good application prospect.