Improvement of imidazolium-based ionic liquids on the activity of ruthenium catalyst for acetylene hydrochlorination

Imidazolium-based Ionic Liquids (IBILs) were employed to synthesize Ru-based catalysts using the Supported Ionic Liquid Phase (SILP) technique for acetylene (C2H2) hydrochlorination, combining the characterizations of transmission electron microscopy (TEM), N-2 adsorption-desorption (BET), thermo-gravimetric analysis (TGA), temperature-programmed desorption (TPD), and X-ray photoelectron spectra (XPS), etc. The optimal Ru10%[BMIM]BF4/AC catalyst achieved the C2H2 conversion of 98.9% and the selectivity to vinyl chloride monomer (VCM) of 99.8% under the temperature of 170 degrees C and the C2H2 gas hourly space velocity (GHSV) of 180 h(-1). Further, other IBILs with different anions were chosen to fabricate Ru-based catalysts, and the catalysts showed high activity and selectivity similar with Ru10%[BMIM]BF4/AC catalyst. It is demonstrated that IBILs additives can significantly improve the dispersion of ruthenium species and prevent the appearance of coke deposition owing to the interactions between Ru species and [BMIM]BF4. Moreover, the oxygen-containing functional groups on the carbon support are associated with the interactions among Ru species and [BMIM]BF4. (C) 2017 Elsevier B.V. All rights reserved.