Activated carbon supported ternary gold-cesium(I)-indium(III) catalyst for the hydrochlorination of acetylene

Commercialization of acetylene hydrochlorination using AuCl3 catalysts has been impeded by its poor stability. We have been studying CsCl as a promoter, which can improve acetylene hydrochlorination activity and has resistance to catalytic deactivation. In-III added to the Au-Cs-I/AC catalysts worked as efficient catalysts for the hydrochlorination of acetylene to vinyl chloride. A series of trimetallic catalysts.1AuxIn(III)4Cs(I)/AC with x = 0.5, 1, 2, 3) were prepared and assessed for their ability to promote hydrochlorination of acetylene. The enhancement of stability observed for a Au/In-III/CsI weight ratio of 1 : 1 : 4 was particularly remarkable. It delivered stable performance within the conversion of acetylene, reaching more than 92.8%, and there was only 3.7% C2H2 conversion loss after running for 50 h under the reaction conditions of a temperature of 180 degrees C and a C2H2 hourly space velocity of 1480 h(-1). Moreover, the 1Au1In(III)4Cs(I)/AC catalyst delivered stable performance with an estimated lifetime exceeding 6520 h at a C2H2 hourly space velocity of 50 h(-1). H-2-TPR, TEM, HCl-TPD, C2H2-TPD, XPS and TGA techniques were further applied to reveal the structural information on the Au-In-III -Cs-I/AC catalysts. The results reveal that the addition of InCl3 increased the electron density of Au3+ species via electron transfer from the In atoms to the Au3+ center which can increase the adsorption of hydrogen chloride and therefore improve the catalytic stability. These results demonstrate that the addition of metal additives CsCl and InCl3 results in a synergistic effect to enhance the activity and the stability of Au-based catalysts. The excellent catalytic performance of the 1Au1In(III)4Cs(I)/AC catalyst demonstrated its potential as an alternative to mercury chloride catalysts for acetylene hydrochlorination.