Patent ID: 7442453

Claim:
A decontamination procedure for a fuel cell power plant ( 10 ), wherein the plant ( 10 ) includes at least one fuel cell ( 12 ) for generating electrical power from hydrogen containing reducing fluid fuel and oxygen containing oxidant reactant streams, a power circuit ( 80 ) for directing the electrical power from the fuel cell ( 12 ) to a primary electrical load ( 82 ), the fuel cell ( 12 ) including an anode electrode ( 24 ) and a cathode electrode ( 42 ) on opposed sides of an electrolyte ( 48 ), an anode flow field ( 22 ) in fluid communication with the anode electrode ( 24 ) for directing the hydrogen fuel to flow through the fuel cell ( 12 ) and adjacent the anode electrode ( 24 ), and a cathode flow field ( 40 ) in fluid communication with the cathode electrode ( 42 ) for directing the oxidant stream to flow through the fuel cell ( 12 ) and adjacent the cathode electrode ( 42 ), the decontamination procedure comprising the steps of: a. operating the fuel cell power plant ( 10 ) to produce electrical power for an operating period by connecting the primary electrical load ( 82 ) to the fuel cell ( 12 ), directing a flow of the oxidant through the cathode flow ( 40 ) field, and directing a flow of the hydrogen fuel through the anode flow field ( 22 ); b. then, whenever electrical power production of the fuel cell ( 12 ) is reduced by at least 5% by contamination of the anode electrode ( 24 ) and/or the cathode electrode ( 42 ), terminating operation of the fuel cell ( 12 ) of the plant ( 10 ) for a decontamination period by disconnecting the electrical load ( 82 ) from the fuel cell ( 12 ); c. then, decontaminating the fuel cell ( 12 ) during the decontamination period by terminating flow of the hydrogen fuel through the anode flow field ( 22 ) and then directing a flow of an oxygen containing oxidant stream through the anode flow field ( 22 ) so that a potential of the electrodes ( 24 , 42 ) rises to between about 1.0 and 1.25 volts, compared to a standard hydrogen reference electrode, to oxidize contaminants adsorbed on at least one of the anode electrode ( 24 ) and cathode electrode ( 42 ) during the operating period.