Catalyst layer operation capability

At the heart of a PEM fuel cell is a polymer membrane that has some unique capabilities. It is impermeable to gases but it conducts protons (hence the name, proton exchange membrane). The membrane that acts as the electrol5q e is squeezed between the two porous, electrically conductive electrodes. These electrodes are typically made out of carbon doth or carbon fiber paper. At the interface between the porous electrode and the polymer membrane there is a layer with catalyst particles, typically platinum supported on carbon [1]. A schematic diagram of cell configuration and basic operating principles is shown in the Figure in.l. 

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