Localized membrane degradation

In an operating fuel cell, the RH and gas partial pressure vary between inlet and outlet, and potential distribution exists in the vicinity of the electrode perimeter, all of which may cause local membrane degradation. 

Localized membrane degradation has been observed at the location of the platinum line for PEMFCs (Escobedo 2006). As shown in Fig. 10, membrane void, cracks, and delamination can be observed. 

During normal operation of PEMECs, the local conditions, such as RH and gas partial pressure, vary from the inlet to the outlet. Several reports have identified the gas inlet area as more vulnerable to membrane degradation compared with the bulk membrane. 

Extracellular degradation removes acetylcholine, the neuropeptides and ATP. Acetylcholine is rapidly hydrolyzed to choline and acetate by acetylcholinesterase. The enzyme is localized in both the presynaptic and the postsynaptic cell membrane and splits about 10,000 molecules of acetylcholine per second. 

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