Electrodes, degradation modes

The typical electrode degradation modes are (1) corrosion of the catalyst metal (both particle growth and dissolution) and (2) corrosion of the carbon materials in electrodes (catalyst support and gas diffusion layer materials). 

Table 3 b Possible Electrode Degradation Modes (mtx = mass transport ECSA = electrochemical surface area)... 

Table 1 Main degradation modes in high-temperature membrane electrode assemblies...

Summarizing Table 1, the potentials typically experienced on PEFC electrodes range from approximately 0 to 1.5 V or more. Since higher potentials promote degradation modes such as carbon corrosion and platinum dissolution, one should strive to minimize exposure to high potentials. Before discussing ways of accomplishing this, we briefly review how potential affects platinum and carbon. 

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