Ionic liquid–solvent systems in the gas–liquid phase for acetylene hydrochlorination

Abstract

Homogeneous mercury-free catalysts synthesized using ionic liquids (ILs) have become increasingly popular due to their high activity and excellent stability for acetylene hydrochlorination. However, high viscosity as well as costliness limit the application of ILs. Here, for the first time, we explored the use of solvents for acetylene hydrochlorination since low-viscosity systems allow rapid mass and heat transfer processes. In the synthesized Ru–ILs–solvent system, tetraphenylphosphonium chloride (TPPC) shows excellent promoting effects on the reaction. Compared with the pure IL phase, the tetramethylene sulfone (TMS) system improves the catalytic performance, while the amount of IL used is reduced by more than 90%. Among the synthesized catalysts, Ru–TPPC–TMS shows the highest conversion rate of about 95% and vinyl chloride selectivity of more than 99.8% under the conditions of 170 °C and GHSV of 50 h⁻¹. Briefly, this study provides new inspiration for the development of homogeneous catalysts for acetylene hydrochlorination.