Morphology Control. Crystalline Nano-carbon-based Composite Body And Electrode Materials

Molybdenum carbide, tungsten carbide is a unique class by owning Pt-likecatalytic activity in acid and Alkaline medium, high stability and resistance to CO gaspoisoning and other features, which are widely used in catalytic hydrogenation,dehydrogenation, isomerization, fuel cells areas, etc. Especially in the direct methanolfuel cell(DMFC), molybdenum carbide, tungsten carbide catalyst for methanolelectro-oxidation respective are much less than Pt, but their participation is conduciveto CO and other intermediate products desorpting from Pt, thus greatly improving thecatalytic activity of precious metals and stability, and reduce the amount of preciousmetals, thereby reducing the production cost of the direct methanol fuel cells.Therefore, the synthesis of molybdenum carbide, tungsten carbide or their compositehas very important significance.The traditional carbon materials have excellentphysical transmission capacity, but its steric hindrance, it is not conducive toapplications since its resistance is so large.The crystalline nanocarbon materials withhigh conductivity and structural stability, is a very good optional material.In this paper, chitosan and polyacrylamide are used as carbonsource.Phosphomolybdic acid hydrate and tungstophosphoric acid are adopted asmolybdenum and tungsten source, and Ni metal salt serve for graphitizing catalyst. Bycoordinating polar groups on the carbon source and metal ions, crystalline nanocarbonbased composite materials is success to be realized synchronous synthesis.By XRD, Raman, TEM, TG, BAS100, and other physical and chemicalcharacterization of the crystalline phase,morphology, phase transition and its directmethanol fuel cell (DMFC) application of each product. The experimental results showthat the chitosan and polyacrylamide with a large number of groups have a certainconfinement effect for the growth of nano-particles, so achieving that complexes of molybdenum carbide and tungsten carbide nano-particles dispersed, also closed tocarbon phase. The material obtained can be successfully used as a carrier and hasshown a superior DMFC carrier effect, the commercialization of fuel cells havepotential applications. This synthetic route also simultaneously in situ, experimentalmethod is simple, material is inexpensive, provide a new way for the synthesis ofmolybdenum carbide, tungsten carbide / crystalline carbon-based composite materials.