Preparation Of Nanoparticle Catalyst Supported On Graphene And The Research Of Their Catalytic Effect On Fuel Cell

In recent years,direct alcohol fuel cells(DAFCs)have become a hot topic because of the wide sources,low-emission,small noise,high transfer efficiency and simple equipment.The development of DAFCs will be in favour of solving the environment pollution and the shortage of fossil fuels.But the research of catalyst with high catalytic efficiency and low price is an important reason that restricts the progress of DAFCs.In our research,we make the best of the advantages of reduced graphene oxide(RGO),which have large active area and fast electron transmission.It was used as the supporting materials for the catalysts,so that the catalytic activities and stability can be improved greatly.Bimetallic palladium-silver nanoparticles(NPs)supported on RGO with different Pd/Ag ratios(Pd-Ag/RGO)were prepared by an easy green method which did not use any additional reducing agents or dispersing agents.The morphology and composition of the Pd-Ag/RGO were characterized by transmission electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,thermogravimetric analysis and Raman spectroscopy.Cyclic voltammetry and chronoamperometry were used to investigate the electrochemical activities and stabilities of these Pd-Ag/RGO catalysts for the electro-oxidation of methanol and ethanol in alkaline media.It was proved that the Pd-Ag/RGO has good catalytic efficiency for DAFCs.Also different ratios of Pd/Ag have different catalytic activities.Bimetallic palladium-cobalt nanoparticles and trimetallic palladium-cobalt-copper nanoparticles supported on reduced oxide graphene with different metal ratios were prepared via sodium borohydride reduction.The morphology and composition of the samples were characterized by transmission electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,and thermogravimetric analysis.Cyclic voltammetry,linear sweep voltammograms and chronoamperometry were used to investigate the electrochemical activities and stabilities of these catalysts for the oxygen reduced reaction in alkaline media.As the addition of the second metal Co and the third metal Cu,the catalytic efficiency was improved.In acide media,metal Mo was used to reduce GO,and got the samples of MoO2 supported on RGO(Mo O2/RGO).Transmission electron microscopy,scanning electron microscope,X-ray diffraction,X-ray photoelectron spectroscopy,and thermogravimetric,ultraviolet and visible spectrophotometer were used to investigated the morphology and composition of the samples.Also the catalysts were tested for the catalytic activities and stabilities of ORR.The result showed that the catalysts can really catalyzed the oxygen reduced reaction with four-electron pathway.