Effect of quantity of polymer on catalysis and superstructure size of polymer-protected Pt nanoclusters

Platinum nanoclusters protected by poly(N-vinyl-2-pyrrolidone) (PVP) were prepared by ethanol reduction of hexachloroplatinic(IV) acid in the presence of PVP. The PVP-protected platinum nanoclusters, prepared at various mole ratios of PVP to platinum, were characterized by transmission electron microscopy (TEM), atomic force microscopy and the Taylor dispersion method. Hydrogenation of methyl acrylate in ethanol under 1 atm of hydrogen at 30°C was used for evaluation of the catalytic activities, revealing that the catalytic activity of platinum nanoclusters depends on the superstructure size of the PVP-protected nanoclusters in dispersion, which can be estimated on the basis of measurements by TEM and the Taylor dispersion method.