NOVELTY - The process comprises decreasing, at a constant current density, flow of pure reformed hydrogen based fuel with respect to a nominal flow of the fuel during a first time period resulting to a stoichiometric coefficient value of 0.5 so as to increase an oxidation potential of a catalytic electrode from an initial value to a first value that is greater or equal to an oxidation potential of pollutant species, and increasing the flow of the fuel corresponding to a second stoichiometric value of 2 during a second time period to accelerate the flow of the fuel towards catalytic sites of an anode.    USE - The process is useful for decontaminating and regenerating a catalytic electrode of a fuel cell, for reacting the fuel cell and for capturing pollutant species such as hydrogen sulfide and carbon monoxide on the catalytic electrode (all claimed), where the fuel cell such as a proton exchange membrane fuel cell is useful for an automotive application.    ADVANTAGE - The process allows efficient and rapid decontamination and regeneration of the catalytic electrode of the fuel cell thus improving the electrical performance of the fuel cell.    DETAILED DESCRIPTION - The process comprises decreasing, at a constant current density, flow of pure reformed hydrogen based fuel with respect to a nominal flow of the fuel during a first time period resulting to a stoichiometric coefficient value of 0.5 so as to increase an oxidation potential of a catalytic electrode from an initial value to a first value that is greater or equal to an oxidation potential of pollutant species, increasing the flow of the fuel corresponding to a second stoichiometric value of 2 during a second time period to accelerate the flow of the fuel towards catalytic sites of an anode, and returning the flow to the nominal value to react the fuel with the catalytic electrode. The catalytic electrode comprises platinum nano-particles supported on carbon clusters. The decreasing step is regulated to achieve a threshold anodic potential (greater than 0.9 V) of the catalytic electrode. The anodic potential is maintained for 1-10 minutes. The first time period and the second time period are few minutes.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a fuel cell.    Polymer membrane (2)    Catalytic layers (3, 4)    Anode compartment (5)    Cathodic compartment (6)    Gaseous diffusion layers. (7, 8)