Highly effective carbon-supported gold-ionic liquid catalyst for acetylene hydrochlorination

Abstract

The sulfur-containing ionic liquid (IL) trimethylsulfonium iodide (C₃H₉SI) was used to synthesize an efficient non-mercuric catalyst with HAuCl₄·4H₂O as a precursor and spherical active carbon (SAC) as a support. Various Au-IL/SAC catalysts were synthesized using the incipient wetness impregnation technique and applied to acetylene hydrochlorination. The 0.3% Au-IL/SAC catalyst showed the best catalytic performance, with an acetylene conversion of 90% at a temperature of 170 °C and gas hourly space velocity (GHSV) of 360 h⁻¹ using water as the solvent. The catalyst also displayed excellent long-term stability: C₂H₂ conversion was maintained at 97% for up to 200 h (T = 170 °C, GHSV = 90 h⁻¹). Brunauer–Emmett–Teller surface area, thermogravimetric analysis, temperature programmed desorption, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy results together showed that the C₃H₉SI additive significantly improved the dispersion of Au species and inhibited coke deposition on the catalyst surface during the acetylene hydrochlorination reaction. The superior activity and stability of the Au-IL/SAC catalyst make it a green catalyst for the industrial application of acetylene hydrochlorination.