Carbon Corrosion Induced by Partial Hydrogen Coverage

A two-dimension model of carbon corrosion induced by the partial coverage of hydrogen on the anode is presented. In proton exchange fuel cells, this degradation mode is caused principally by two mechanisms: 1) blockage of hydrogen from a portion of the anode under steady-state conditions, and 2) transitioning between the off state and a normal operating state. Whereas, corrosion of anode supports because of insufficient fuel is well known, corrosion of the cathode supports under these conditions is less well understood and likely a larger contributor of degradation than commonly expected. Under certain conditions the overpotential in the cell may reach values greater than 1.5 V.