Investigation of the Carbon Corrosion Process for Polymer Electrolyte Fuel Cells Using a Rotating Disk Electrode Technique

The carbon corrosion process of low surface-area Pt/XC72 and high-surface-area Pt/BP2000 was investigated using an developed accelerated durability testing (ADT) method under simulated fuel cell conditions (a Rotating Disk Electrode (RDE) approach). Compared with the complex MEA system, this innovated approach using RDE can simply focus on carbon corrosion process and avoid the use of MEA in which many degradation/corrosion processes simultaneously occur. A steam etching experiment was also carried out for further understanding of the carbon corrosion process for XC72 and BP2000. It was observed that different carbon corrosion processes resulted in different performance (electrochemical active surface area, mass activity and double layer capacity) decay of catalysts. The corrosion process was studied using TEM. It was found that in the case of Pt/XC72, major corrosion occurred at the center of the Pt/XC72 particle, with some minor corrosion on the surface of the carbon particle removing some amorphous carbon black filaments, while in the case of Pt/BP2000, the corrosion started on the surface. The understanding of carbon corrosion process provides the guidance for making high corrosion resistance catalysts to increase the durability performance of PEFC.