Preparation Of Pt - Based Nanometer Fracture Structure And Its Electrocatalytic Methanol Performance

Direct methanol fuel cell （DMFC） has become the developing direction of the fuel cell in the future due to its advantages such as simple structure, high energy density, easy to carry and pollution-free, etc. Anode and cathode catalyst activity and stability are key determinants of the DMFC performance. Platinum （Pt） catalyst is recognized as the most efficient DMFC catalyst, however its low reserves, high cost and easy to poison limits the commercialization of DMFC progress severely. At the same time, the non-platinum catalyst activity and stability need further improved, to meet the standard of commercial applications. Composition, morphology and structure of controllable Pt-based nanocatalyst, due to the unique surface structure and showed excellent physical and chemical properties has been widely studied, especially in the field of catalysis. Especially, highly dendrites catalyst tend to have large specific surface, in favour of the exposure of active sites, while improve the catalytic performance can also greatly reduce the dosage of precious metals, In this paper, based on the principle of simple operation, mild conditions and environment friendly signs of controllable preparation and properties of electrode materials. Specific content as follows:1. Ethylenediamine tetramethylene phosphonic acid （EDTMP） as complexing agent and stabilizer, with formaldehyde （HCHO） as the reducing agent to reduct the EDTMP-Ptâ…¡ complex for the preparation of phosphate functional Pt nanodendrites. The morphology and structure characteristics of the product was first comprehensive characterization. The results show that the proper reducing agent and Cl-/O₂ etching that generates the morphology structure of the branch. By cyclic voltammograms and i-t current test, the functional catalyst has higher catalytic activity and stability than commercial Pt towards MOR.2. The polyallylamine （PAH） functionalized Pt-Cu bimetal alloy nanodendrites （Pt-Cu BANDs） are synthesized successfully through a one-pot hydrothermal method. Use polyene acryl amine hydrochloride （PAH） as complexing agent, stabilizer and crystal-facet choose agent, formaldehyde as reducing agent. We propose a simple feasible green synthesized by hydrothermal morphology rules of Pt-Cu bimetal alloy nanodendrites. The components, structure and morphology of the Pt-Cu BANDs were overall characterization, explore the formation mechanism of induced reduction and oxidation etching. Cyclic voltammograms（CV） and chronoamperometry curves test （i-t curve） confirmed that Pt-Cu BANDs shows that its superior electric catalytic in terms of methanol oxidation activity （mass activity and specific activity）, and the stability in comparison with commercial Pt black catalyst. This is thanks to the combination of synergetic and electronic effect.3.Through the prophase work of prepared Pt-Cu BANDs as a template, K₂PdCl4 as the etching agent, based on the galvanic displacement reaction mechanism for the in situ preparation of PtPdCu alloy concave octahedral （PtPdCu ACNOs） catalyst. The morphology, composition and structure of PtPdCu ACNOs were characterized by transmission electron microscope （TEM）, scanning electron microscope （SEM）, element distribution （Mapping）, energy dispersive X-ray spectrometer （XPS）, X-ray diffraction （XRD） etc. The activity of PtPdCu ACNOs, Pt-Cu BANDs and commercial Pt were evaluated by Cyclic voltammograms（CV） and chronoamperometry curves test （i-t curve）. The results exhibits that PtPdCu ACNOs showed higher catalytic activity, poison resistance and stability compared to both Pt-Cu BANDs and commercial Pt catalyst.