Self-oxidation of Au-[Bmim][Cl3] catalyst with enhanced activity and stability for acetylene hydrochlorination

There is great potential for carbon-supported gold catalysts to replace toxic mercuric chloride-based catalysts in the acetylene hydrochlorination, which is a key process for producing PVC. However, the catalyst design is essentially hindered by the difficulties in enhancing the catalytic activity of cationic gold and suppressing the deactivation of active species. We report a strategy for self-oxidation of Au3+ by the Au-SILP system with the [Bmim][Cl3] ILs. This strategy can stabilize all gold species in the state of highly oxidized Au3+ instead of coexisting in the Au3+/Au+ site, which makes the catalyst exhibit excellent catalytic activity. High coordination numbers Au-Cl entities reduce the electron transfer between Au3+ and C2H2 and weaken the adsorption of C2H2 on the Au active sites. Furthermore, [Bmim][Cl3] ILs can self-oxidize gold nanoparticles on the support surface into Au3+. This study provides a new method for improving the stability and activity of gold-based acetylene hydrochlorination catalysts.