Fabrication And Performance Study Of Direct Methanol Fuel Cell Catalytic Layer Based On Graphene

Direct methanol fuel cells(DMFCs)have been widely studied by scholars from various countries since it came into being in the last century due to their high energy conversion efficiency,convenient fuel addition,simple battery design and many other advantages.However,the slow oxidation rate of methanol in the anode catalytic layer of DMFC and the catalyst poisoning are two major technical difficulties hindering the commercialization of DMFC.Therefore,the research and development of new catalytic layers has become a key technology for the development of DMFC.As a new type of DMFC catalyst carrier,graphene,due to its unique structure,is formed by a single layer of carbon atoms through sp2 hybridization to form a two-site honeycomb structure..There is huge potential for improving the catalytic efficiency of catalysts and the anti-toxicity of catalysts,which has been widely concerned by domestic and foreign researchers.Graphene is usually prepared in the following ways:micro-mechanical exfoliation high-order pyrolysis graphite method,epitaxial growth method,Chemical vapor deposition(CVD),chemical reduction method and hydrothermal method.Among them,graphene aerogel prepared by hydrothermal method has three-dimensional microscopic pore structure and certain mechanical strength,and is an excellent material for manufacturing DMFC catalyst carrier.Therefore,this topic intends to use graphene as the DMFC anode catalyst carrier to replace the currently widely used carbon black carrier to explore its catalytic oxidation performance for methanol.This article starts from four levels,and conducts research on catalyst carrier preparation,catalyst preparation,catalyst layer preparation and single-cell performance test respectively,inferring the influence of different preparation parameters on these four levels,and then obtaining the best DMFC membrane electrode Preparation parameters.First,the graphene-based aerogel was prepared using a composite guided hydrothermal method,and then the graphene-based aerogel was ground and redispersed,sprayed onto a carbon cloth to prepare a graphene-based catalytic layer,and finally a hot-pressed membrane electrode assembly was prepared,install batteries to test DMFC performance.In this paper,the microscopic morphology,element distribution,thermal reduction effect,precious metal mass fraction,hydrophilic and hydrophobic properties,and electrical conductivity of the prepared catalyst and catalytic layer are studied in detail using Scanning electron microscope(SEM),transmission electron microscope(TEM),laser confocal micro-Raman spectrometer,thermogravimetric analysis(TGA),angular contact measuring instrument and four-probe conductivity tester.Finally,combining the research results,the above work is summarized,and the influence of the preparation parameters on the above four levels is discussed in detail.