Ethanol chemisorption on core–shell Pt-nanoparticles: an ab initio study

Abstract: By means of ab initio calculations, we have investigated the chemisorption properties of ethanol onto segregating binary nanoalloys (NAs). We select nanostructures with icosahedral shape of 55 atoms with a Pt outermost layer over an M-core with M = Ag, Pd, Ni. With respect to nanofilms with equivalent composition, there is an increase of the ethanol binding energy. This is not merely due to observed shortening of the Pt–O distance but depends on the nanoparticle distortion after ethanol adsorption. This geometrical distortion within the nanoparticle can be interpreted as a radial breathing, which is sensitive to the adsorption site, identified by the O-anchor point and the relative positions of the ethyl group. More interestingly, being core-dependent larger in Pd@Pt and smaller in Ni@Pt, it relates to an effective electron transfer from ethanol and the M-core towards the Pt-shell. On the view of this new analysis, Pd@Pt NAs show the most promising features for ethanol oxidation.