Preparation Of Novel Bimetallic Nanomaterials And Their Electrochemical Catalytic Properties Research

Direct alcohol fuel cells (DAFCs) have been used extensively due to their advantages including high efficiency, easy operation, safety, and environmental friendliness. Up to date, the main catalysts used in DAFCs are Pt or Pt-based bimetallic nanomaterials. The catalytic properties, including activity and stability of the catalyst, are important determinants of the fuel cell performance. Thus, scientists from all over the world are dedicated to the design and preparation of nanomaterials with excellent catalytic properties. As the catalytic properties of nanomaterials are highly dependent on their morphologies, sizes, components, and crystal structures, we have synthesized a series of new catalysts with good performance via modifying their morphologies, structures, and components to improve their catalytic activity and stability. The main contents are shown below:(1) A simple, facile and one-pot solvothermal method was developed for preparation of reduced graphene oxide (RGO) supported hollow Ag@Pt core-shell nanospheres (hAg@Pt), using ethylene glycol as a reducing agent and sodium dodecyl sulfate (SDS) as a soft template. Control experiments demonstrated that the molar ratios of the Pt-Ag precursors, the amount of SDS, the presence of GO, and the reaction temperature were critical to the final nanocomposites. The as-prepared hAg@Pt-RGO showed the improved electrocatalytic activity and durability toward ethylene glycol oxidation in alkaline medium.(2) A simple solvothermal method was developed for fabrication of PtRu nanodendrites supported on RGO (PtRu-RGO) in the ethylene glycol system, using hexadecylpyridinium chloride (HDPC) as a shape-directing agent. Based on the observation the morphology and structure of the PtRu nanodendrities, we speculated that their proposed formation mechanism may be ascribed to the particle attachment and self-aggregation of initially formed small branches. The as-prepared nanocomposites showed the superior catalytic activity and better stability towards ethylene glycol oxidation, compared with RGO-supported Pt nanoparticles and commercial PtRu/C (Pt 30 wt.%, Ru 15 wt.%) catalysts.(3) Popcorn-like PtAu nanoparticles were fabricated by a facile wet-chemical method in the presence of PVP using H2PtCl4 and HAuCl4as precursors, glucosamine as morphology directing and reducing agent. The PtAu nanoparticles were further supported on RGO by simple ultrasonication. The prepared PtAu-RGO nanocomposites showed an enhanced catalytic performance toward oxygen reduction reaction and methanol oxidation reaction, in comparison with Pt-RGO and commercial 10% Pt/C catalysts.(4) A simple one-pot solvothermal approach was developed for preparation of Pt3Co nanoflowers by co-reduction of Pt(acac)2 and Co(acac)3 in oleylamine, without any seed or template. The as-prepared Pt3Co nanoflowers showed the enhanced catalytic performance for oxygen reduction reaction in comparison with solid Pt3Co nanoparticles and commercial Pt black catalysts. Meanwhile, Pt3Co nanoflowers exhibited the improved catalytic activity and long-term stability towards methanol oxidation reaction, using solid Pt3Co nanoparticles and commercial Pt black catalysts as references.(5) Bimetallic alloyed PtPd nanoflowers were fabricated by one-pot solvothermal co-reduction of Pt(acac)2 and Pd(acac)2 in oleylamine system. The as-prepared nanostructures showed the enhanced electrocatalytic activity for oxygen reduction reaction. Meanwhile, PtPd nanoflowers displayed good methanol tolerance and improved stability for oxygen reduction reaction.