Electrophoretic Deposited Pt/C/SiO2 Anode for Self-Humidifying and Improved Catalytic Activity in PEMFC

Abstract

In this study, the electrophoresis deposition (EPD) method was employed to prepare hydrophilic Pt/C/SiO2 anode for obtaining self-humidifying membrane electrolyte assemblies (MEAs). The SiO2 nanospheres prepared by sol gel method are with 65nm diameter averagely. The self-humidifying MEAs consist of hydrophilic anodes, JM-GDE cathode, and polymer electrolyte (Nafion 212, DuPont), were prepared via hot pressing and then incorporated into single cell (9cm2) for testing. Effects of SiO2 mass fraction and humidity on Pt mass activity and long-term durability are discussed. Besides the addition of SiO2 nanospheres, Pt mass activity on anode was enhanced from 1941 to 2856mA/mgPt while operating under the operating cell voltage of 0.6V and 100% relative humidity (RH) condition. Furthermore it also enhanced from 1529 to 2709mA/mgPt under cell operation conditions of 0.6V and 30 % RH. For the long-term durability under severe condition (<30% RH), the routine single cell manifests a significant voltage decline of about 15.5%. While single cell with our proposed hydrophilic anodes shows only 4.5% of voltage declining rate for exceeding 560hours operating. Our proposed methodology in this study not only results in an outstanding Pt mass activity but also in an excellent slef-humification.