[Report] Identification of single-site gold catalysis in acetylene hydrochlorination
There remains considerable debate over the active form of gold under operating conditions of a recently validated gold catalyst for acetylene hydrochlorination. We have performed an in situ x-ray absorption fine structure study of gold/carbon (Au/C) catalysts under acetylene hydrochlorination reaction conditions and show that highly active catalysts comprise single-site cationic Au entities whose activity correlates with the ratio of Au(I):Au(III) present. We demonstrate that these Au/C catalysts are supported analogs of single-site homogeneous Au catalysts and propose a mechanism, supported by computational modeling, based on a redox couple of Au(I)-Au(III) species. Authors: Grazia Malta, Simon A. Kondrat, Simon J. Freakley, Catherine J. Davies, Li Lu, Simon Dawson, Adam Thetford, Emma K. Gibson, David J. Morgan, Wilm Jones, Peter P. Wells, Peter Johnston, C. Richard A. Catlow, Christopher J. Kiely, Graham J. Hutchings