Cyanide leaching of Au/CeO2: highly active gold clusters for 1,3-butadiene hydrogenation

Abstract

Ceria-supported gold catalysts before and after leaching by NaCN were investigated by X-ray absorption spectroscopy at the Au L_III edge. After gold leaching, isolated gold cations remain in close interaction with the support. These ions form an ideal precursor to very small clusters of a few gold atoms upon reduction. The resulting gold clusters exhibit a very high intrinsic activity in the hydrogenation of 1,3-butadiene, which is at least one order of magnitude higher than that of the nanometre-sized gold particles in the non-leached parent catalyst. These findings point to a very strong structure sensitivity of the gold-catalyzed hydrogenation of dienes.