Crown Jewel catalyst: How neighboring atoms affect the catalytic activity of top Au atoms?

This work aims to develop an efficient catalyst for aerobic glucose oxidation and obtain a clear structure-activity relationship of the catalyst. It is a well-known fact that catalytic sites are located on the surface of the metal, especially at the tops (vertexes) with a high coordination vacancy. By constructing crown jewel Pd/Au (CJ-Pd/Au) nanostructures via a replacement reaction of Pd atoms at active top, sites of the mother cluster with Au ions, we disclose herein a new approach to synthesize a novel Pd/Au catalyst containing an abundance of top Au atoms on a large scale. Tuning the number of the neighboring Pd atoms coordinating with Au atoms at the top position is shown to result in the changes of Au's electronic structure, which leads to significantly enhanced activities for aerobic glucose oxidation of the top Au atoms. The CJ-Pd/Au catalyst showed a very high catalytic activity for glucose oxidation, and the top Au atoms decorating the Pd NCs were 20-30 times more active than the Au atoms of Au NCs with a size of 1.4-nm diameter. The highest catalytic activity of the top Au atoms could be associated with its high negative charge and its unique structure. (C) 2013 Elsevier Inc. All rights reserved.