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

Abstract

The high cost and poor atom utilization efficiency of noble metal catalysts have limited their industrial applications. Herein, we designed CeO 2 -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 CeO 2 -supported single Au(III) ion catalysts was much higher than that of the homogeneous catalyst NaAuCl 4 . 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 CeO 2 was responsible for yielding ketonic ester.

Enhanced Oxygen Evolution Reaction Activity of Co Ions Isolated in the Interlayer Space of Buserite MnO2

“…Clearly, the Co ions intercalated in the layered MnO 2 possess much higher catalytic activity than those in the other states. This indicates that a high utilization efficiency of Co ions is realized by isolating them, where the state of Co ions is quite different from those bound in the oxide network and is similar to homogeneous catalysts . The Tafel slope of Co/MnO 2 was smaller than that of α-Co­(OH) 2 , reflecting better electron transfer kinetics.…”

“…The particle size effects in Co­(oxide)-based catalysts were explored in a number of important reactions, including Fischer–Tropsch synthesis and CO 2 hydrogenation. , However, little has been reported on the size dependency for the OER . On the other hand, single-ion catalysts of Au or Pt supported on the surface of oxides such as CeO 2 and ZrO 2 provided enhanced utilization efficiency and selectivity. , The supported single-atom catalysts can not only reduce the use of noble metals but also have a high utilization efficiency comparable to that of homogeneous catalysts. These previous studies motivated us to isolate Co ions to enhance their catalytic activity toward the OER.…”

“…10 On the other hand, single-ion catalysts of Au or Pt supported on the surface of oxides such as CeO 2 and ZrO 2 provided enhanced utilization efficiency and selectivity. 11,12 The supported single-atom catalysts can not only reduce the use of noble metals but also have a high utilization efficiency comparable to that of homogeneous catalysts. These previous studies motivated us to isolate Co ions to enhance their catalytic activity toward the OER.…”

Tailoring the Selectivity of Bio‐Ethanol Transformation by Tuning the Size of Gold Supported on ZnZr10Ox Catalysts

“…Evidently, changing the fashion of gold loading enables control over product distribution. The influence of sodium on selectivity control was effectively ruled out by performing the reaction over 3Au/ZnZr‐DP samples prepared by a modified DP method using an ammonia solution …”

The Sub‐Nanometer Scale as a New Focus in Nanoscience

“…However, the performance of SACs is highly related to the substrate, or the ligand anchoring the single metal atom. Currently, several different substrates exist, such as transition metal oxides, metals, metal–organic frameworks, nitrogen doped carbon materials, porphyrin, and other types of substrates with defects or undercoordinated sites . The substrates not only serve to anchor metal atoms, but also give rise to the activity.…”