Rejuvenation of automotive fuel cells

A process for rejuvenating a fuel cell, the process comprising:

• providing a fuel cell having an anode, a cathode, and a polymer electrolyte membrane between the anode and the cathode, the cathode having an initial value of current density at a chosen cell voltage;
• allowing the fuel cell to generate electricity over a chosen period of time after which the cathode has a second value of current density less than the initial value at the same chosen voltage, a difference between the initial value and the second value over the chosen period of time representing a rate of performance loss;
• dehydrating the fuel cell;
• and thereafter
• exposing the cathode to a flow of a gas having less than 5% water at a temperature of from about 80° C. to about 200° C.;
• and
• rehydrating the fuel cell, wherein the sequence of dehydration, gas exposure, and rehydration rejuvenates the fuel cell as indicated by an increase in the current density from the second value to a third value following rehydration.