Abstract: A fuel cell includes a proton-exchange membrane, and a cathode and anode fixed on its opposite sides. The anode delimits a flow conduit between a molecular-oxygen inlet area and a water outlet area. The cathode includes a support for catalyst material. The support has first and second materials to which catalyst is fixed, the first material being a graphitized material. The second material has a resistance to corrosion by oxygen that is greater than that of the first material. A quantity of the second material at the inlet area is greater than a quantity of the second material at the water outlet. The cathode comprises a first layer including the first material and a second layer including the second material. A thickness of the second layer decreases between the molecular-oxygen inlet area and the water outlet area.

Abstract: A method of manufacturing a catalyst for a PtxMy-based PEMFC, M being a transition metal, including the steps of: depositing PtxMy nanostructures on a support; annealing the nanostructures; depositing a PtxMy layer at the surface of the nanostructures thus formed; and chemically leaching metal M. It also aims at the catalyst obtained with this method.

Abstract: A method for depolluting and regenerating a catalytic fuel-cell electrode, the reaction of the fuel of the cell and capture of at least one polluting species occurring on the catalytic electrode, comprises: a decrease, at a constant first reference current density, in fuel flow, relative to a nominal fuel flow, for a first length of time, leading to a value for the stoichiometric coefficient of fuel lower than 1, to increase oxidation potential on the catalytic electrode and reach oxidation potential of the polluting species, to eliminate it; a cut-off of current for a cut-off time; an increase in flow above nominal flow, leading to a value of stoichiometric coefficient higher than or equal to 1; and an increase in current density until a second current density chosen by operator and possibly identical to or different from the initial reference current density, is reached.

Abstract: The invention concerns an active layer for an electrochemical reactor comprising:—a carbon electronic conductor which is not a fullerene as a support; and —a catalytic system made up of one or more metals and a fullerene. It also concerns an electrochemical reactor integrating such an active layer.

Abstract: A method of using a proton exchange membrane fuel cell, composed of a polymer membrane and electrodes present on either side of the membrane, includes at least one step of reversing the functioning of the cell during use.

Abstract: An electrode for an electrochemical system, such as a fuel cell, is formed by an active layer including: pores; at least one catalyst; at least one ionomer; and electrically-conductive particles. The catalyst content per pore ranges between 30 and 500 mg/cm3 with respect to the pore volume.

Abstract: The invention relates to a method for extending the lifetime of a PEMFC fuel cell that includes the step of supplying, at anode 3, a chemical compound capable of reacting with oxygen, but not originating from the fuel.

Abstract: A fuel cell includes a proton-exchange membrane, and a cathode and anode fixed on its opposite sides. The anode delimits a flow conduit between a molecular-oxygen inlet area and a water outlet area. The cathode includes a support for catalyst material. The support has first and second materials to which catalyst is fixed, the first material being a graphitized material. The second material has a resistance to corrosion by oxygen that is greater than that of the first material. A quantity of the second material at the inlet area is greater than a quantity of the second material at the water outlet. The cathode comprises a first layer including the first material and a second layer including the second material. A thickness of the second layer decreases between the molecular-oxygen inlet area and the water outlet area.

Abstract: A method of manufacturing a catalyst for a PtxMy-based PEMFC, M being a transition metal, including the steps of: depositing PtxMy nanostructures on a support; annealing the nanostructures; depositing a PtxMy layer at the surface of the nanostructures thus formed; and chemically leaching metal M. It also aims at the catalyst obtained with this method.

Abstract: A method for depolluting and regenerating a catalytic fuel-cell electrode, the reaction of the fuel of the cell and capture of at least one polluting species occurring on the catalytic electrode, comprises: a decrease, at a constant first reference current density, in fuel flow, relative to a nominal fuel flow, for a first length of time, leading to a value for the stoichiometric coefficient of fuel lower than 1, to increase oxidation potential on the catalytic electrode and reach oxidation potential of the polluting species, to eliminate it; a cut-off of current for a cut-off time; an increase in flow above nominal flow, leading to a value of stoichiometric coefficient higher than or equal to 1; and an increase in current density until a second current density chosen by operator and possibly identical to or different from the initial reference current density, is reached.

Abstract: A device for determining the CO concentration in a gas containing hydrogen is provided, including a detection electrode in contact with the gas, and a counter electrode, each being in contact with an electrolyte; a current source to deliver a current with a predetermined intensity between the detection electrode and the counter electrode so as to generate, at the detection electrode, an electric potential fluctuating between two threshold values due to the adsorption and desorption of the CO at the detection electrode; a device for measuring the potential; and a calculating device to determine the CO concentration, connected to the current source and to the device for measuring the potential, for calculating a characteristic parameter of the fluctuations of the potential, and for determining the CO concentration from the calculated characteristic parameter and the intensity of the applied current.

Abstract: A fuel cell having a proton-exchange membrane, an anode, and a cathode. The anode and cathode are fixed on opposing sides of the proton-exchange membrane. The anode demarcates a flow conduit between a molecular-hydrogen inlet area and a molecular-hydrogen outlet area. A quantity of catalyst at the molecular-hydrogen outlet area is smaller than a quantity of catalyst at the molecular-hydrogen inlet area. The anode also has a thickness that decreases continuously between the molecular-hydrogen inlet and outlet areas.

Abstract: A method for measuring the reproducibility of N unitary ion exchange membrane/electrode assemblies, where N is an integer strictly greater than 1, each assembly containing an ion exchange membrane located between an anode fed with a first stream and a cathode fed with a second stream and possessing cell voltage characteristics, comprises the following steps: delivering to each unitary assembly a stream containing at least one polluting species for a given time; measuring at least one electrochemical parameter of each assembly; and comparing said measurements so as to evaluate the reproducibility of said assemblies.

Abstract: An electrode for an electrochemical system, such as a fuel cell, is formed by an active layer including: pores; at least one catalyst; at least one ionomer; and electrically-conductive particles. The catalyst content per pore ranges between 30 and 500 mg/cm3 with respect to the pore volume.

Abstract: The method for supplying power from a fuel cell detects a sulphur oxide in the oxidising gas of the cell and decreases the operating temperature of the cell when the quantity of sulphur oxide detected is greater than a predetermined threshold. The temperature decrease can vary according to the degradation rate of the performances.

Abstract: The invention concerns an active layer for an electrochemical reactor comprising:—a carbon electronic conductor which is not a fullerene as a support; and —a catalytic system made up of one or more metals and a fullerene. It also concerns an electrochemical reactor integrating such an active layer.

Abstract: The method for managing a fuel cell having an active gas flowing in contact with an electrode includes a step of comparing the concentration of a sulfur compound in the active gas with a threshold indicative of a sulfur compound pollution phase and a step of temporary introducing an oxygenated and non-sulfur polluting gas into the active gas if the concentration is higher than the threshold. The polluting gas can be introduced during or after the pollution phase.

Abstract: The method of using a fuel cell (1) of the PEFMC type, composed of a polymer membrane (2) and electrodes (3, 4) present on either side of the membrane (1), according to the invention comprises at least one step of reversing the functioning of the cell during use.

Abstract: The invention relates to a device for determining the CO concentration in a gas containing hydrogen, said device comprising a detection electrode (1) in contact with said gas and separated from a counter electrode (2) by an electrolyte (3; 4). In a galvanostatic mode, the fluctuations of the hydrogen oxidation potential of the detection electrode (1) are characterized by a parameter having a value used for obtaining the CO concentration by comparison to reference data.

Abstract: The invention relates to a method for extending the lifetime of a PEMFC fuel cell that includes the step of supplying, at anode 3, a chemical compound capable of reacting with oxygen, but not originating from the fuel.