Palladium nanoparticles consisting of metallic cores and encapsulating shells serve as an intriguing, catalytic model system. This investigation is aimed at enhancing our understanding of the surface composition of palladium nanoparticles synthesized in polyol and exploiting their encapsulating shells to understand the catalytic properties of the nanoparticles more rationally. We investigated the surface structure of palladium nanoparticles by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). FTIR spectra showed the presence of monoalkoxide species with tilted geometry. TGA further confirmed the presence of these species along with some adsorbed byproducts formed during the reaction. Atomic force microscopy (AFM) shows the presence of diffused negatively charged coatings on the surface of the nearly spherical nanoparticles. (C) 2008 Elsevier B.V. All rights reserved.