Supported single Au(Ⅲ) ion catalysts for high performance in the reactions of 1, 3-dicarbonyls with alcohols

The high cost and poor atom utilization efficiency of noble metal catalysts have limited their industrial applications. Herein, we designed CeO₂-supported single Au(Ⅲ) ion catalysts with ultra-low gold loading that can enhance the utilization efficiency of gold atoms and bridge the gap between homogeneous and heterogeneous gold catalysis. These catalysts were highly active and reusable for the reaction of 1, 3-dicarbonyls with alcohols. The catalytic turnover number of CeO₂-supported single Au(Ⅲ) ion catalysts was much higher than that of the homogeneous catalyst NaAuCl₄. In addition, the effects of gold loading and the drying method for the catalysts on the organic reactions were systematically explored. In-depth investigation of the structure–property relationship by highresolution transmission electron microscopy, hydrogen temperature-programmed reduction, X-ray absorption near edge structure analysis, UV–vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy revealed that the isolated Au(Ⅲ) ions were related to the active sites for the synthesis of β-substituted cyclohexenone and that CeO₂ was responsible for yielding ketonic ester.