Platinum Nanoparticles Stabilized by Polyvinylpyrrolidone for Hydrogenation

Nanosized colloidal platinum was prepared by reduction of H2PtCl6 in methanol-water mixture by refluxing. The particle size and morphology were characterized by transmission electron microscopy and electron diffraction. The influence of polyvinylpyrrolidone (PVP) molecular mass (MM), PVP concentration, and reduction time on platinum particle size was investigated. Small (1–2 nm) Pt particles are formed in the case of PVP with MM = 1.2×104. With increasing polymer MM and decreasing polymer concentration, large aggregates from small particles appear. High catalytic activity of the obtained colloidal platinum in hydrogenation of acetylene compounds is shown. The effect of Pt particle size on the catalytic activity was studied.