Preparation Of Metal Phthalocyanine-functionalized Graphene Supported Pt And Flower-like PtNi Alloy Catalysts And Their Performance For Methanol Electrooxidation

This thesis put emphasis upon studies of the fabrication of sulfonated metal phthalocyanine functionalized graphene-supported Pt nanocatalysts with high performance,and the effect of different metal phthalocyanine functionalization molecules on the catalytic performance was investigated.Moreover,the effect of synthesis conditions and morphology of flower-like PtNi alloy on methanol oxidation was also investigated.It involves the discipline forefront of nanomaterials,electrocatalysis,surface science and energy science.The main original results obtained are as follows(1)With sulfonated cobalt phthalocyanine(CoTsPc)functionalized graphene(CoTsPc-G)as the carrier,a new anode catalyst(Pt/CoTsPc-G)for DMFC applications was prepared by depositing Pt nanoparticles via the hydrothermal method.The prepared materials were characterized by UV-Vis absorption spectroscopy,Raman spectroscopy,scanning electron microscopy(SEM),transmission electron microscopy(TEM),thermogravimetric analysis(TGA),X-ray diffraction(XRD),X-ray energy dispersive spectroscopy(EDX),X-ray photoelectron spectroscopy(XPS)and electrochemical tests.The results show that the CoTsPc-G support can significantly reduce the particle size of platinum nanoparticles,and thus increase the electrochemical active surface area of the catalyst.Electrochemical tests show that the Pt/CoTsPc-G catalyst can significantly improve the electrocatalytic activity,stability and CO-tolerance ability for methanol oxidation in acidic medium(2)The Pt nanocatalysts(Pt/MTsPc-G)were prepared by functionalizing graphene with different sulfonated metal phthalocyanine molecules(e.g.,cobalt phthalocyanine,nickel phthalocyanine,copper phthalocyanine and zinc phthalocyanine).UV-vis spectroscopy,Raman spectroscopy,XRD and electrochemical methods were used to characterize the prepared materials.The electrochemical results show that the Pt catalysts prepared by using different metal phthalocyanine functionalized graphene as the carrier could obviously enhance the electrocatalytic activity and stability of the catalyst for methanol oxidation.The activity order of the catalysts for methanol oxidation is as follows:Pt/NiTsPc-G>Pt/ZnTsPc-G>Pt/CuTsPc-G>Pt/CoTsPc-G>Pt/G>commercial Pt/C(3)With chloroplatinic acid and nickel nitrate as the metal precursors and ethanolamine as the reductant,a new flower-like platinum-nickel alloy catalyst(Pt4Ni-F)was successfully prepared by the hydrothermal method.The physical characterizations were carried out by SEM,TEM,XRD,XPS and EDS.The electrochemical stability and activity tests were carried out by cyclic voltammetry and chronoamperometry.It is found that the Pt4Ni-F has better catalytic activity and stability than the spherical PtNi alloy,commercial Pt/C and commercial Pt black for methanol oxidation in acidic medium.