Preparations of platinum nanoparticles and their catalytic performances

This work investigates the effect of reducing agents and stabilizing agent on the preparation of platinum nanoparticles. We used H₂PtCl₆as a precursor and hydrogen and sodium borohydride as reducing agents to prepare colloidal platinum nanoparticles. Polyvinylpyrrolidones (PVPs) is used as a stabilizing agent. Hydrogen and sodium borohydride are used as reducing agents. The prepared platinum nanoparticles are characterized by transmission electron microscopy (TEM) and X-ray diffractometer (XRD). The concentrations of the precursor and the stabilizing agent influence the size of platinum nanoparticles, while the reducing agents influence the morphologies and structures of platinum nanoparticles. Supported platinum catalysts (CPt-NaBH₄, CPt-H₂) are prepared from colloidal platinum nanoparticles and γ-Al₂O₃. For comparison, another supported platinum catalyst (IPt) is prepared by the conventional impregnation method with an aqueous H₂PtCl₆ solution and γ-Al₂O₃. The catalytic activities of CPts are superior to that of IPt on the basis of benzene conversion.