H2 Starvation Model

In the fully developed H2 starvation region, where H2 is completely depleted, the cathode electrode potential reaches its maximum value as determined by the mixed potential of all electrochemical reactions involved at the cathode, namely, COR and OER. The reaction current therein is determined by 02 crossover (ix o2) from cathode through membrane to anode, where only ORR takes place in the absence of H2. Charge balance yields 

Equation (8) states the fact that the sum of carbon corrosion current (f co, = /cor,call,) and oxygen evolution current (/o2 = /oER.cath) on the cathode must be equal to the oxygen reduction current on the anode determined by the 02 crossover rate  

the gas permeability through the membrane is calculated by the semiempirical correlation44 

The kinetic model described by Eq. (8) can be used to evaluate the material impact on the carbon corrosion rate. As shown for 50% Pt/Vulcan in Fig. 4 and Table 3 (first row), its carbon corrosion rate is essentially equal to the 02 crossover current. Since the 

Catalyst, Catalyst-Support, and Membrane Material Impact on Maximum Catalyst-Support Corrosion Rate Under Fully Developed H2 Starvation Conditions. Here, Advanced-Support is a Hypothetical Support with a 30-Fold Lower Corrosion Rate than Graphitized Vulcan Carbon and Membrane-X Refers to a Hypothetical Membrane with a 10-Fold Lower 02 Permeability. 

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