Studies On Structures And Catalytic Properties Of Platinum-Group Bimetallic Nanoclusters With Organic Molecules

This dissertation focuse on structures and catalyst properties of platinum-group bimetallic nanoclusters with organic stabilizers. The main topics are described as follows:1. Effect of poly(vinylpyrrolidone)(PVP) on structure and properties of platinum bimetallic nanoclusters. Pt-Rh and Pt-Ru bimetallic nanoclusters were prepared by microwave synthsis method with and without the presence of PVP before the formation of the metal colloidal nanoclusters. Reaction activities of the Pt-Rh and Pt-Ru nanoclusters on the hydrogenation of o-CNB and cyclohexene and characterization results of TEM,FTIR,XPS and XRD indicated that two kinds of Pt-Rh and Pt-Ru bimetallic clusters had different structures and catalytic properties. PVP that have carbonyl groups could influence the surface composition of the platinum-group bimetallic nanoclusters and thereby their catalytic properties. For Pt-Rh bimetallic nanoclusters, because Rh atoms are apt to assemble on the surface layer with the presence of PVP, catalytic properties of PVP-PtRh bimetallic nanoclusters gain much contribution from Rh atoms. For Pt-Ru bimetallic nanoclusters, because Pt atoms are apt to assemble on the surface layer with the presence of PVP, catalytic properties of PVP-PtRu bimetallic nanoclusters get greatly effect from Pt atoms.2. Studies on effect of amino-conpounds on structure and catalysis of PVP-stabilized Pt-Rh bimetallic nanoclusters. Two kinds of PVP-stabilized PtRh bimetallic nanoclusters were got with the addition of triethanolamine and hexadecylamine in the formation of metal colloidal nanoclusters. Reaction activities of o-CNB and 4-nitrophenol over the Pt-Rh nanoclusters showed that Rh atoms are apt to assemble on the surface layer of PtRh bimetallic nanoclusters with the presence of amino-compounds. The present work provides a way for turning the structures and properties of bimetallic clusters purposefully.