Studies On Syntheses Of Precious Metal Nanoclusters And Their Catalytic And Magnetic Properties

This dissertation is focused on synthese of precious metal nanoclusters and their catalytic, magnetic properties. The main topics are:1) Synthese of polyvinylpyrrolidone(PVP)-stabilzed palladium metal nanoclusters, including colloidal Pd/iron oxide and supported Pd/Fe₂O₃, Pd/Fe₃O₄ and Pd-Pt/Fe₃O₄, by chemical reduction method and its characterization by TEM and VSM. The supported Pd/Fe₃O₄ and Pd-Pt/Fe₃O₄ exhibit strong magnetism. These catalysts could be isolated from other matters by an extra magnetic field. Hydrogenation of o-chloronitrobenzene (o-CNB) over Pd/Fe₃O₄ and Pd-Pt/Fe₃O₄ presents better catalytic properties than that over Pd and Pd-Pt nanoclusters. The Pd/Fe₃O₄ and Pd-Pt/Fe₃O₄ catalysts can be repeatedly used in many times.2) PVP-stabilized Au colloidal nanoparticles were prepared by microwave irradiation. Effect of the alcohol reducing agent and NaOH on particle size and shape was investigated. The Au nanoparticles were...