Identification of single-site gold catalysis in acetylene hydrochlorination

A new paper published today in Science reveals the active-site in gold based acetylene hydrochlorination reaction.

Work pioneered by Prof. Graham Hutchings and in collaboration with Johnson Matthey has improved the commercial production of the industrially important feedstock, vinyl chloride.  Previously produced using the hazardous mercuric chloride catalyst, a more environmentally friendly catalyst of gold supported on carbon now replaces mercuric chloride.

However, considerable debate has reigned over the active for of gold under reaction conditions.  In the present work, the team with the help of the facilities at the Diamond Synchrotron, performed in-situ x-ray absorption fine structure studies of the Au/C catalysts under acetylene hydrochlorination reaction conditions, to revealing the highly active catalysts comprise of single-site cationic Au entities whose activity correlates with the ratio of Au(I):Au(III) present.

Supported by computational work supported, Malta et al have shown the Au/C catalysts are supported analogues of single-site homogeneous Au catalysts operating on a redox couple of Au(I)-Au(III) species.

The work is published in Science, Vol. 355, Issue 6332, pp. 1399-1403.