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

Commercialization of acetylene hydrochlorination using AuCl 3 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 (1Au x In 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 /Cs I 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% C 2 H 2 conversion loss after running for 50 h under the reaction conditions of a temperature of 180 °C and a C 2 H 2 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 C 2 H 2 hourly space velocity of 50 h −1 . H 2 -TPR, TEM, HCl-TPD, C 2 H 2 -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 InCl 3 increased the electron density of Au 3+ species via electron transfer from the In atoms to the Au 3+ 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 InCl 3 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. Promoting the effect of indium( iii ) on activated carbon supported gold-cesium( i ) catalyst in acetylene hydrochlorination.