NOVELTY - Improving electrical performance of an operating fuel cell (20) catalyst-containing cathode in fuel cell connected to electrical load, involves: reducing flow of air to cathode (15); disconnecting the load (45) from fuel cell; connecting a potentiostat to fuel cell; cycling an applied voltage, current, or power to fuel cell; disconnecting potentiostat from fuel cell; reconnecting load to fuel cell; and resuming flow of air to cathode.    USE - For improving electrical performance of operating fuel cell catalyst-containing cathode in fuel cell (claimed).    ADVANTAGE - The method enables rapid recovery of a deactivated Proton exchange membrane fuel cell (PEMFC) cathode, without the use of an external inert gas. The oxygen in the air is consumed by the cathode, leaving behind a gas mainly composed of nitrogen, thus allow electrochemical recovery of the Pt or other catalysts at high potentials without the occurrence of irreversible oxidation processes. The method uses fuel cell during operational period to power electrical load, and begins by reducing existing flow of air to the cathode. An advantage of using the method to recover deactivated fuel cell instead of purging the fuel cell with clean air is that recovery may be both faster and more effective, where 70 hour air purge is capable of recovering 20% of the cell's initial activity. Another advantage of using method instead of exposing cell to open circuit voltages is that recovery with this method may be much faster, where exposing cell to open circuit voltage takes 3 hours to partially recover the cell performance. In contrast, the present recovery method achieves 100% recovery within 3 minutes. Further, the method does not require an external inert gas because inert gas is produced inside cathode during recovery procedure, and has advantage over shutting down cell that it does not require the turn down of entire balance of plant, which exposes cell to corrosive cell reversal conditions. Another potential advantage over a simple voltage pulse to 1.4 V is that it produces better recovery in comparable time scales because (bi)sulfate formed at 1.4 V is desorbed at the lower potentials and Pt is reduced. In the method, it is not required that the gas flows be stopped and it doesn't over expose the cell to voltage were Pt oxidation is detrimental to catalyst surface area.    DESCRIPTION OF DRAWING(S) - The figure shows process flow diagram of proton exchange membrane fuel cell recovery.    Proton exchange membrane fuel cell (10)    cathode (15)    Fuel cell (20)    Air feed (30)    Load (45)    External switch (50)