Chitosan-stabilized gold, gold-palladium, and gold-platinum nanoclusters as efficient catalysts for aerobic oxidation of alcohols

Chitosan was used as a stabilizer for the synthesis of Au, AuPd and AuPt nanoclusters (NCs). The produced NCs had a narrow particle size distribution with sizes less than 2.3 nm in diameter and were characterized by various techniques such as UV-Visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and scanning electron microscope energy dispersive spectroscopy (STEM-EDS). These metal NCs exhibited high catalytic activity toward the aerobic oxidation of various alcohols under ambient conditions comparable with the reported Au:PVP catalyst. Au NCs protected by chitosan could easily be recovered for repeated use. (C) 2011 Elsevier B.V. All rights reserved.