Fabrication Of Pt/Au-PAN Catalytic Electrodes And Electrocatalytic Properties For Methanol Oxidation

Direct methanol fuel cells (DMFCs) have attracted enormous attention as power sources for portable electronic devices and transportation owing to wealthy fuel, the high-energy conversion efficiency, simplicity for storing and safety for operating. However, the commercialization process of DMFC has been seriously hampered since that the oxidation of methanol in the anode reaction exists serious polarization and it is a process of poisoning caused by reaction intermediates. Currently, we mainly focus on reseaching how to improve the catalyst performance. In this paper, substrates of hybrid fiber membranes (Au-PAN) have been prepared by combining the electrospinning and electroless plating methods. And then the catalytic electrodes (Pt/Au-PAN) have been prepared by using electrochemical deposition and electroless deposition methods to form a layer of platinum nanoparticles in the Au-PAN. Finally, we study their catalytic properties for methanol oxidation.(1) Polyacrylonitrile (PAN) nanofibers containing gold salt have been prepared by electrospinning technique. After the gold salt was reduced by NaBH4, the gold nanoparticles were formed. By using the gold nanoparticles as seeds, thin continuous gold films have been depositeded on the surface of PAN fibers through self-catalyzed reduction of chloroauric acid in solution.(2) The catalytic electrodes (Pt/Au-PAN) have been prepared by using electrochemical deposition and chemical deposition methods to form a layer of platinum nanoparticles in the substrates of Au-PAN. Then they were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffractometer (XRD).(3) The electrocatalytic properties of the obtained fibrous mats electrode above have been tested. Meanwhile, the Pt/C/Au-PAN electrodes by the wetting-drying method have also been fabricated and investigated in the same condition. The results show that the prepared Pt/Au-PAN electrodes using the Au-PAN fibrous as substrates by electrochemical deposition and electroless deposition methods exhibit better activity and stability than the corresponding commercial Pt/C/Au-PAN electrodes.