Single-Atom AuI–N₃ Site for Acetylene Hydrochlorination Reaction

The gold-catalyzed acetylene hydrochlorination reaction is an important process to produce vinyl chloride monomer in the polyvinyl chloride industry. The traditional catalyst of carbon-supported AuCl 3 is inclined to be reduced by acetylene and lose its activity during the reaction process. Here, we presented the construction of Au I –N 3 active sites through single gold atom dispersed on g-C 3 N 4 (Au 1 /g-C 3 N 4 ), which shows robust catalytic performance toward acetylene hydrochlorination. The Au species is shown to have Au I oxidation state, and it is coordinated with three nitrogen atoms of tri-s-triazine repeating units, which is consistent with density functional theory (DFT) modeling and XAFS measurements. Through DFT study, we demonstrate that the Au I –N 3 sites tend to coordinate with HCl than C 2 H 2 in the initial reaction. The Au I –N 3 sites cannot be reduced into Au 0 oxidation state easily and thus maintain their activity as stable catalytic active sites. The single-atom-site Au catalyst with nitrogen coordination environment and corresponding electronic state provides an efficient pathway for acetylene hydrochlorination reaction.