Degradation cathode potential measurement

Combined with the presence of the Pt catalyst, which accelerates this reaction, measurable CO2 production occurs above 1.0 V. While this indicates that slow corrosion will occur at open circuit potential, the rate is still relatively low, but is enough to contribute to degradation over longer lifetimes. However, the key driver for corrosion of the carbon support is the increased potentials that typically occur during shutdown or startup, when the cathode potential can go up to 1.5 V or higher [461. 

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