Pt / C And Metal Oxide Composite Anode Materials Developed

Recently direct methanol fuel cell (DMFC) has received widespread attention dueto the abundant fuel source, the low price and safety of the storage and transportation ofthe fuel. Nevertheless, the step toward the practical application has not been promotedas fast as that people expected. One of the major problems that rearding its practical useis due to the used Pt catalyst, which has relatively low electrocatalytic activity towardsthe methanol oxidation reaction and easy to be poisoned by the intermediates ofmethanol oxidation reaction. In order to reduce the amount of Pt catalyst used, improvethe electrocatalytic activity and utilization ratio, we prepare a series highly dispersed Ptcomposite electrodes. The phase evolution and electrochemical property of thecomposite electrode was characterized by cyclic voltammetry (CV),XRD and TEMmethod etc.The main results obtained were as follows:(1) Pt/C catalyst was prepared by liquid phase reaction method and Pt particle sizewas successfully controlled. It was found that the electrocatalytic activity of Pt/Ccatalyst (homemade) is similar to Pt/C (ETEK) catalyst.(2) Nano size CeO₂ round and clubbed particles were prepared through sol-gel andhydrothermal synthesis methods, respectively. Pt-CeO₂/C composite catalyst wasobtained by mixing CeO₂ with Pt/C (homemade) catalyst. It is found that Pt-CeO₂/Ccatalyst with CeO₂ round particles exhibts improved electrocatalytic activity for themethanol oxidation reaction. The Current density for methanol electro-oxidation is112.3 mA·cm^-2.(3) Nano size MnO_x round particles were obtained from solid phase reaction andoxidation-reduction method. Pt-MnO_x/C catalyst was prepared with two differentmethods. It was found that Pt-MnO_x/C catalyst mixed with Mn₂O₃ round particles hashigher electrocatalytic activity for the methanol oxidation. The Current density for methanol electro-oxidation is 84.9 mA·cm^-2.The experiment results demonstrate that Pt-MO_x/C catalysts mentioned in thisthesis have high electrocatalytic activity for the methanol oxidation reaction. Theobtained composite catalysts have potential application in DMFC.