Activated-Carbon-Supported Gold-Cesium(I) as Highly Effective Catalysts for Hydrochlorination of Acetylene to Vinyl Chloride

The synthesis of vinyl chloride from acetylene by hydrochlorination has gained tremendous interest in coal-based chemistry. Bimetallic gold-cesium(I)/activated carbon (Au-Cs-I/AC) catalysts were found to have a higher catalytic activity and stability for acetylene hydrochlorination when compared with gold catalysts. Over 1Au-4Cs(I)/AC catalysts, the maximum conversion of acetylene was 94% and there was only 5% C2H2 conversion loss after 50 h of running time. Moreover, the 1Au-4Cs(I)/AC catalyst delivered a stable performance during a 500 h test with the conversion of acetylene and the selectivity of vinyl chloride reaching more than 99.8 and 99.9 %, respectively. Temperature-programmed reduction of H-2, temperature-programmed desorption of C2H2, and X-ray photoelectron spectroscopy techniques were further applied to detect structural information on the Au-Cs-I/AC catalysts. Additives of CsCl indeed stabilized the catalytically active Au3+ species and inhibited the reduction of Au3+ to Au-0, thereby improving the activity and long-term stability of gold-based catalysts.