Reseach On Graphene-Baesd Metal Catalyst For Properties Of Direct Alcohol Fuel Cells

Energy issues always relate to the country's economic lifeline. As a potential new way to supply energy, Direct Alcohol Fuel Cells has drawn a great deal of attention, but there are still many problems with its catalysts. With its appearance, researches and concerns on Graphene used as the supporter bearing the metal catalysts have been a focus just attributing to its superior performance. In this study, Graphene and Nitrogen (N)-doped Graphene were synthesized by solvent-thermal method, and both Graphene and N-doped Graphene supported Pt and Pt-Ru nanoparticles were prepared via the method of ethylene glycol reduction. Using XRD Analysis characterized the composition of the prepared samples, and through electro-chemical techniques such as Cyclic Voltammetry method (CV) and Electrochemical Impedance Spectroscopy (EIS) it was studied in detail that both methanol and ethanol electro-catalytic oxidation properties for Pt/G, Pt-Ru/G, Pt/NG and Pt-Ru/NG under the acidic condition. Besides, in this work, Pt/G and Pt-Cu/G were synthesized by the impregnation-reduction method, and then these catalysts were tested using technologies like CV and EIS in order to determine those mechanisms of methanol and ethanol electro-oxidation in acidic environment. Those catalysts in the acidic electrolyte had showed superior properties, and however, having many different characteristics from the former system, the alkaline electrolyte had drawn many concerns. Different composition ration catalyst like Pt/G, Ni/G, Pt-Ni(1:1)/G, Pt-Ni(1:2)/G and Pt-Ni(2:1)/G were loaded on the graphene via the ethylene glycol reduction, and then employ electrochemical techniques such as CV, EIS and I-t to study and analyze these catalysts' electrocatalytically properties for the methanol oxidation reaction in the alkaline electrolyte with different concentrations. From many aspects, for example, catalytic activity, CO tolerance, interfacial resistance and stability and so on, these factors demonstrated the 0.75M electrolyte was better, and through a comprehensive consideration, the conclusion was that the catalyst Pt-Ni(1:1)/G is the best among all sorts in the section. Moreover, in this thesis, applying strategies like CV, EIS and I-t to made a complete check for Pt/G, Co/G, Co-Cr/G and Pt-Co-Cr/G catalysts in different electrolyte concentration mainly for methanol oxidation reaction, and the result was that the properties of Pt-Co-Cr/G was preferable in 0.75M and 1.0M. The research aiming for these metal-based catalysts was to sustain catalytic activity and stability, and in the same time to curtail costs, finally making forward to accomplish the target to replace the noble metal with those non-precious metals.