Palladium nanoparticles supported on polyvinylpyridine: Catalyticactivity in Heck-type reactions and XPS structural studies

Abstract

Palladium nanoparticles, obtained by metal vapour synthesis (MVS), weredeposited on cross-linked polyvinylpyridine. The Pd/PVPy system showedhigh catalytic activity in the Heck C-C coupling reaction of iodo- andbromo-arenes (iodobenzene, bromobenzene, p-nitrobromobenzene,p-bromoacetophenone, p-(methoxy)bromobenzene) with alkyl acrylates(methyl acrylate, n-butyl acrylate, ethylhexyltrans-3-(4-methoxyphenyl)acrylate) at 100 degrees C-175 degrees Cworking under nitrogen atmosphere as well as in air. The catalyst isstable and the leaching of metal in solution is very low. When reused,the recovered Pd/PVPy maintains the catalytic activity of the pristinematerial. XPS structural studies performed on the starting catalyst aswell as on the recovered one indicate the presence of a interactionbetween the basic nitrogen of the pyridine present in the polymer andthe metal. (C) 2009 Elsevier Inc. All rights reserved.