Abstract: The present invention provides a method for generating a gas that may be used for startup and shutdown of a fuel cell. In a non-limiting embodiment, the method may include generating a nitrogen-rich stream; merging the nitrogen-rich stream with a hydrocarbon fuel stream into a feed mixture stream; and catalytically converting the feed mixture into a reducing gas.

Abstract: A direct formate fuel cell (DFFC) employs at least one formate salt as the anode fuel, either air or oxygen as the oxidant, a polymer anion exchange membrane (AEM) to separate the anode and cathode, and metal catalysts at the anode and cathode. One exemplary embodiment consists of palladium nanoparticle anode catalyst and platinum nanoparticle cathode catalyst, each applied to the alkaline AEM in the form of a thin film. Operation of the DFFC at 60° C. with 1 M KOOCH+2 M KOH as the anode fuel and electrolyte and oxygen at the cathode produces 144 mW cm?2 of peak power density, 181 mA cm?2 current density at 0.6 V, and an open circuit voltage of 0.931 V. This performance is competitive with alkaline direct liquid fuel cells (DLFCs) reported in the literature and demonstrates that formate fuel is a legitimate contender with alcohol fuels for alkaline DLFCs.

Abstract: A hydrogen evolution device that liberates hydrogen upon passage of an electric current, wherein an amount of liberated hydrogen is proportional to an amount of the current, includes at least one hydrogen evolution cell including an electrochemically oxidizable anode, a hydrogen cathode and an electrolyte, and at least one heating resistor thermally coupled to the hydrogen cathode directly or via a solid or liquid heat conductor.

Abstract: A fuel cell includes membrane electrode assemblies disposed in a planar arrangement. Each membrane electrode assembly includes an electrolyte membrane, an anode catalyst layer, and a cathode catalyst layer disposed counter to the cathode catalyst via the electrolyte membrane. Interconnectors (conductive members) are provided on the lateral faces of the electrolyte membranes disposed counter to each another in the neighboring direction of the membrane electrode assemblies. Each interconnector includes a support portion protruding toward the central region of the electrolyte member on the cathode side of the electrolyte membrane. The support portion is in contact with the cathode-side surface of an edge of the electrolyte membrane, and the electrolyte membrane is held by the support portion.

Abstract: An electrochemical cell having two or more diffusion bonded layers, which demonstrates a high degree of ruggedness, reliability, efficiency and attitude insensitiveness, is provided. The novel cell structure simplifies construction and operation of these cells. Also provided is a method for passive water removal from these cells. The inventive cell, as well as stacks made using these cells, is suitable for use in applications such as commercial space power systems, long endurance aircraft, undersea power systems, remote backup power systems, and regenerative fuel cells.

Abstract: The invention provides part solid, part fluid and flow electrochemical cells, for example, metal-air and lithium-air batteries and three-dimensional electrode arrays for use in part solid, part fluid electrochemical and flow cells and metal-air and lithium-air batteries.

Abstract: An apparatus and method is disclosed for recovering a flammable vapor emanating from a vent of a tank. The apparatus comprises an input conduit for connecting to the vent of the tank. An input manifold connects the input conduit to an input of a compressor with an output manifold connecting an output of the compressor to an input of a storage tank. An output conduit connects an output of the storage tank to the turbine generator for generating electrical power by processing the flammable vapor. An electrical connector directs electrical power from the turbine generator to drive the apparatus as well as to supply surplus power to an external load.

Abstract: A burning device is provided for fuel cell to be run under high temperature. The burning device uses a specific-designed fuel spraying device having porous medium. The burning device can be used under different statuses of flow in the fuel cell. With the burning device, the fuel cell has improved efficiency by enhancing recycling of system heat and pollution of discharged waste gas is reduced.

Abstract: An apparatus for generating electrical energy at altitude, comprising a tether connecting a substantially ground level location, part to a platform at an elevated location, the tether comprising a conduit coupled to an electrical generator at the platform, the conduit arranged to allow the flow of a fuel fluid from the substantially ground level location to the elevated location, and the electrical generator being operable to convert energy in the fuel fluid to electrical energy at the elevated location.

Abstract: A device for reducing carbon dioxide includes a cathode chamber including a cathode electrolyte solution and a cathode electrode, an anode chamber including an anode electrolyte solution and an anode electrode, and a solid electrolyte membrane. The anode electrode includes a nitride semiconductor region on which a metal layer is formed. The metal layer includes at least one of nickel and titanium. A method for reducing carbon dioxide by using a device for reducing carbon dioxide includes steps of providing carbon dioxide into the cathode solution, and irradiating at least part of the nitride semiconductor region and the metal layer with a light having a wavelength of 250 nanometers to 400 nanometers, thereby reducing the carbon dioxide contained in the cathode electrolyte solution.

Abstract: An electrochemical power system is provided that generates an electromotive force (EMF) from the catalytic reaction of hydrogen to lower energy (hydrino) states providing direct conversion of the energy released from the hydrino reaction into electricity, the system comprising at least two components chosen from: a catalyst or a source of catalyst; atomic hydrogen or a source of atomic hydrogen; reactants to form the catalyst or source of catalyst and atomic hydrogen or source of atomic hydrogen, and one or more reactants to initiate the catalysis of atomic hydrogen. The electrochemical power system for forming hydrinos and electricity can farther comprise a cathode compartment comprising a cathode, an anode compartment comprising an anode, optionally a salt bridge, reactants that constitute hydrino reactants during cell operation with separate electron flow and ion mass transport, and a source of hydrogen.

Abstract: A non-microbial fuel cell utilizing an organic fuel containing a hydroxyl group and a non-metallic catalyst is disclosed. Compositions for use in and methods for generating electric energy from chemical energy using fuel cells are also disclosed. Compositions for use in and methods of storing energy using fuel cells are also disclosed.

Abstract: In one example embodiment, an electronic device uses a fuel cell which reduces thickness of the overall fuel cell while reducing electrical resistance. In one example embodiment, a flow path that distributes an electrolyte is included between a fuel electrode and an oxygen electrode. In one example embodiment, a current collector on the fuel electrode side has a pair of current collector terminals in opposing-corner positions. Similarly, a current collector on the oxygen electrode side has a pair of current collector terminals in opposing-corner positions. The current collector terminals project outside the fuel cell. Thereby, connection of unit cells within the battery is facilitated, a monopolar plate structure becomes easier to use as the current collector, and distance of flowing current is shortened.

Abstract: In one embodiment, an electrical power storage system using hydrogen includes a power generation unit generating power using hydrogen and oxidant gas and an electrolysis unit electrolyzing steam. The electrical power storage system includes a hydrogen storage unit storing hydrogen generated by the electrolysis and supplying the hydrogen to the power generation unit during power generation, a high-temperature heat storage unit storing high temperature heat generated accompanying the power generation and supplying the heat to the electrolysis unit during the electrolysis, and a low-temperature heat storage unit storing low-temperature heat, which is exchanged in the high-temperature heat storage unit and generating with this heat the steam supplied to the electrolysis unit.

Abstract: The present invention provides a method for evaluating the properties of hydrogen to improve the safety of hydrogen fuel, and provides a method for selecting proper odorants for hydrogen. Odorized hydrogen containing suitable odorants in appropriate concentrations with hydrogen are also provided.

Abstract: An electrochemical energy storage device comprising a primary positive electrode, a negative electrode, and one or more ionic conductors. The ionic conductors ionically connect the primary positive electrode with the negative electrode. The primary positive electrode comprises carbon dioxide (CO2) and a means for electrochemically reducing the CO2. This means for electrochemically reducing the CO2 comprises a conductive primary current collector, contacting the CO2, whereby the CO2 is reduced upon the primary current collector during discharge. The primary current collector comprises a material to which CO2 and the ionic conductors are essentially non-corrosive. The electrochemical energy storage device uses CO2 as an electroactive species in that the CO2 is electrochemically reduced during discharge to enable the release of electrical energy from the device.

Abstract: The invention relates to a method of making alkali metal silicide compositions, and the compositions resulting from the method, comprising mixing an alkali metal with silicon and heating the resulting mixture to a temperature below about 475° C. The resulting compositions do not react with dry O2. Also, the invention relates to sodium silicide compositions having a powder X-ray diffraction pattern comprising at least three peaks with 2Theta angles selected from about 18.2, 28.5, 29.5, 33.7, 41.2, 47.4, and 56.2 and a solid state 23Na MAS NMR spectra peak at about 18 ppm. Moreover, the invention relates to methods of removing a volatile or flammable substance in a controlled manner. Furthermore, the alkali metal silicide compositions of the invention react with water to produce hydrogen gas.

Abstract: The present invention relates to an anode supported solid-oxide fuel cell based flame fuel cell that enable the generation of both electricity and heat from a flame (i.e. flame is used as a heat source and a fuel source for the fuel cell's operation, while supplying a useful heat for other thermochemical systems) and, more particularly, to an anode supported solid-oxide fuel cell based flame fuel cell that uses hydrocarbon/air mixture as a fuel source and includes a catalyst layer that can act as a protective layer for the anode layer, an anode layer, a cathode layer, an electrolyte layer, and an interlayer between the cathode layer and the electrolyte layer.

Abstract: While the operation of a fuel cell is stopped, a pressure decrease caused by a current sweep is suppressed from being misjudged as being the occurrence of a hydrogen leak or a cross leak, and the judgment accuracy of the hydrogen leak, etc. is improved. In order to realize this feature, during an intermittent operation, in which, when a load on the fuel cell system is low, electrical power is supplied from a power storage unit in the fuel cell system to a power-consuming apparatus and power generation of a fuel cell is temporarily stopped, in the situation where a current sweep for suppressing a degradation of the fuel cell is performed, a hydrogen pressure in an anode of the fuel cell is corrected based on hydrogen consumed by the current sweep, and a hydrogen leak judgment based on a pressure decrease or a cross leak judgment based on a pressure decrease is performed on the basis of the corrected hydrogen pressure.

Abstract: An electrochemical energy conversion and storage system comprises an electrochemical energy conversion device, in fluid communication with a source of an organic liquid carrier of hydrogen and an oxidant, for receiving, catalyzing and electrochemically oxidizing at least a portion of the hydrogen to generate electricity, a hydrogen depleted liquid, and water; and a vessel for receiving the hydrogen depleted liquid; wherein the organic liquid carrier of hydrogen comprises at least two secondary hydroxy groups is provided.

Abstract: There is provided an air battery having a power generation body, the power generation body comprising: a laminate in which a negative electrode, a separator, a positive electrode having a catalyst layer and a positive electrode current collector, and an oxygen diffusion membrane are laminated in this order; and an electrolyte being in contact with the negative electrode, the separator and the positive electrode, wherein one of main surfaces of the oxygen diffusion membrane is arranged facing one of main surfaces of the positive electrode current collector; and at least a part of a peripheral edge part of the oxygen diffusion membrane is in contact with atmospheric air.

Abstract: A device (1) for performing mechanical work and/or producing electrical or thermal energy, the energy necessary for operation is obtained from the oxidation of carbonaceous fuels (20) into carbon dioxide (24) and water (23). The device comprises means (14) for compression and/or condensation of the exhaust gas (21), and storage means (15) for receiving the compressed and/or condensed exhaust gas (21).

Abstract: A solid oxide cell is provided which, after short-time activation, can generate electricity at a high power density over a prolonged period. This cell can be constituted so as to eliminate the necessity of carrier gas introduction during power generation and, hence, can more easily realize a size reduction in power generation systems. The solid oxide cell at least has an anode having an anode material, a cathode having a cathode material, and an electrolyte disposed between the anode and the cathode and including an ionically conductive solid oxide, wherein the anode material includes a composite metal oxide or a cermet, solid carbon is deposited on the anode material during activation and at least the following reaction schemes (1) and (2) are utilized at the anode during power generation to generate electricity.

Abstract: A method for refilling a hydrogen reservoir comprising a first hydrogen-storing material comprises establishing a fluid connection between the hydrogen reservoir and a cartridge containing a second hydrogen-storing material. The second hydrogen-storing material releases hydrogen at a pressure sufficient to charge the first hydrogen-storing material. Some embodiments involve heating the second hydrogen-storing material and/or allowing heat to flow between the first and second hydrogen-storing materials.

Abstract: A bipolar plate for fuel cells includes a flow plate having a first surface for the introduction of hydrogen fuel gas and water vapor and a second surface for the introduction of an oxygen containing gas, wherein at least a portion of the first and/or second surface comprises a nanostructured carbon material (NCM) coating deposited thereon, said coating having a thickness of 1 nm to 5 ?m.

Abstract: In certain embodiments, a cartridge includes a fuel chamber configured to store a fuel. The fuel chamber has a fuel outlet port configured to interface with a fuel inlet port of a fuel cell such that the fuel may be supplied to the fuel cell. The cartridge further comprises an oxidizing agent chamber configured to store an oxidizing agent. The oxidizing agent chamber has an oxidizing agent outlet port configured to interface with an oxidizing agent inlet port of the fuel cell such that the oxidizing agent may be provided to the fuel cell.

Abstract: The present invention provides a technology related to a fuel cell system capable of adjusting a discharge amount of an odorant discharged to an outside of a moving body according to a state of the moving body. The fuel cell system mounted to a moving body includes: a fuel cell which generates electric power by electrochemically reacting a hydrogen gas with an oxidation gas; and a adjusting portion which adjusts an amount of an odorant to be discharged to an outside of the moving body according to a state of the moving body, the odorant being included in an anode off-gas discharged from an anode side of the fuel cell.

Abstract: An electrochemical method for providing hydrogen using ammonia, ethanol, or combinations thereof, comprising: forming an anode comprising a layered electrocatalyst, the layered electrocatalyst comprising at least one active metal layer deposited on a carbon support; providing a cathode comprising a conductor; disposing a basic electrolyte between the anode and the cathode; disposing a fuel within the basic electrolyte; and applying a current to the anode causing the oxidation of the fuel, forming hydrogen at the cathode.

Abstract: The present invention provides a fuel cell in which an electrolyte electrode assembly having an electrolyte sandwiched between an anode and a cathode is provided between separators, each of the separators including: a sandwiching section which sandwiches an electrolyte electrode assembly and includes a fuel gas channel and a separately provided oxygen-containing gas channel; a bridge which is connected to the sandwiching section and includes a reactant gas supply channel; a reactant gas supply section which is connected to the bridge and includes a reactant gas supply passage; and a connecting section that connects the sandwiching section to the bridge.

Abstract: The present invention pertains to a high differential pressure electrochemical cell which encompasses a high pressure chamber and a low pressure chamber, said chambers being separated by a membrane, the membrane being ion-conductive, in particular proton-conductive, and electrically insulating, the membrane having a first surface in the high pressure chamber and a second surface in the low pressure chamber, the first surface being provided with a first electrode, and the second surface being provided with a second electrode, the first and second electrodes being electroconductively connected to each other via an electric circuit, wherein the membrane comprises at least two ion-conductive layers, wherein at least one of said ion-conductive layers is electrically insulating and at least one of said ion-conductive layers is electrically conductive. The high differential pressure electrochemical cell preferably is an ionic gas compressor, an ionic gas decompressor, or a high pressure electrolyser.

Abstract: A power source and hydride reactor is provided that powers a power system comprising (i) a reaction cell for the catalysis of atomic hydrogen to form hydrinos, (ii) a chemical fuel mixture comprising at least two components chosen from: a source of catalyst or catalyst; a source of atomic hydrogen or atomic hydrogen; reactants to form the source of catalyst or catalyst and a source of atomic hydrogen or atomic hydrogen; one or more reactants to initiate the catalysis of atomic hydrogen; and a support to enable the catalysis, (iii) thermal systems for reversing an exchange reaction to thermally regenerate the fuel from the reaction products, (iv) a heat sink that accepts the heat from the power-producing reactions, and (v) a power conversion system. In an embodiment, the catalysis reaction is activated or initiated and propagated by one or more other chemical reactions such as a hydride-halide exchange reaction between a metal of the catalyst and another metal.

Abstract: An electrochemical cell apparatus that can operate as either a fuel cell or a battery includes a cathode compartment, an anode compartment operatively connected to the cathode compartment, and a carbon fuel cell section connected to the anode compartment and the cathode compartment. An effusion plate is operatively positioned adjacent the anode compartment or the cathode compartment. The effusion plate allows passage of carbon dioxide. Carbon dioxide exhaust channels are operatively positioned in the electrochemical cell to direct the carbon dioxide from the electrochemical cell.

Abstract: A utility supply system supplies a fluid containing an antioxidant of a gaseous phase to a stack of proton-exchange membrane fuel cells, for efficient removal of hydroxyl radicals.

Abstract: A fuel composition for a fuel cell includes at least one primary fuel that produces protons and electrons, and at least one peroxide. As an example, the primary fuel may be at least one aqueous solution containing methanol, ethanol, or formic acid. When the fuel composition is used, the catalytic activity can increase, and thus a fuel cell having improved performance can be manufactured.

Abstract: A system and a method for suppressing the build up of metal carbonates in the electrolyte, using a porous cell separator is used to allow the use of different electrolyte compositions around the anode (anolyte) and the cathode (catholyte). This cell configuration enables the oxygen cathode to operate in a molten hydroxide electrolyte, and the carbon anode to operate in mixed carbonate-hydroxide melt, so that most of the advantages of using a molten hydroxide electrolyte will be retained.

Abstract: The present invention provides a catalyst precursor substance containing copper, zinc, and aluminum and exhibiting an X-ray diffraction pattern having a broad peak at a specific interplanar spacing d (?). The present invention also provides a method for producing the catalyst precursor substance by mixing a solution containing a copper salt, a zinc salt, and an aluminum salt with a solution containing an alkali metal hydroxide or an alkaline earth metal hydroxide, thereby forming a precipitate. In the present invention, a catalyst is prepared through calcining of the catalyst precursor; the catalyst is employed for water gas shift reaction; and carbon monoxide conversion is carried out by use of the catalyst.

Abstract: At shutdown of a fuel cell system, a system-shutdown controller is configured to cause a current extraction device to extract current from a fuel cell in a state where a supply of a fuel gas through a fuel supply system is continued and a supply of an oxidant gas through an oxidant supply system is stopped, and the system-shutdown controller is configured to airtightly close fresh-air control valves after increasing pressure of the fuel gas in a fuel electrode to not less than atmospheric pressure and not less than pressure of the oxidant gas in an oxidant electrode.

Abstract: Disclosed is a fuel cell device comprising: a fuel cartridge to accumulate a fuel therein; and a fuel cell device main body to generate electric power by using the fuel accumulated in the fuel cartridge, wherein the fuel cell device main body is provided with a cartridge conveying body, the fuel cartridge being attached to and detached from the cartridge conveying body, and the cartridge conveying body is provided so as to be rotatable with respect to the fuel cell device main body.

Abstract: Conveying gas containing sulfur through a sulfur tolerant planar solid oxide fuel cell (PSOFC) stack for sulfur scrubbing, followed by conveying the gas through a non-sulfur tolerant PSOFC stack. The sulfur tolerant PSOFC stack utilizes anode materials, such as LSV, that selectively convert H2S present in the fuel stream to other non-poisoning sulfur compounds. The remaining balance of gases remaining in the completely or near H2S-free exhaust fuel stream is then used as the fuel for the conventional PSOFC stack that is downstream of the sulfur-tolerant PSOFC. A broad range of fuels such as gasified coal, natural gas and reformed hydrocarbons are used to produce electricity.

Abstract: A system and method for starting up a fuel cell system are disclosed. Briefly described, an embodiment for starting an electrochemical reaction between a fuel and an oxidant during a start-up process includes a fuel cell stack operable to output a nominal voltage during a normal operating condition and operable to output a reduced start-up voltage during the start-up process, and includes at least one balance of plant (BOP) device that supports operation of the fuel cell stack, operable at a nominal output when sourced by the fuel cell stack at the nominal voltage, and operable at a reduced output when sourced by the fuel cell stack at the reduced start-up voltage.

Abstract: A fuel cell system that includes a liquid fuel tank containing a non-sulfur-containing liquid fuel and water; a reformer generating a hydrogen-rich gas from the liquid fuel and water received from the liquid fuel tank; a reformer burner heating the reformer by burning a gaseous fuel received from a gaseous fuel tank, and a fuel cell stack generating electrical energy from the hydrogen-rich gas received from the reformer. The liquid fuel tank is connected to the gaseous fuel tank, and the liquid fuel mixed with water is supplied to the reformer by the pressure of the gaseous fuel tank.

Abstract: Embodiment of a system for generating electric power with micro fuel cells comprising at least one first micro cell and at least one second micro cell, each micro cell having an anode and a cathode with a membrane being sandwich-wise interposed, the system comprising a spacer element having an annular element that surrounds a cavity, said spacer element being associated with said anode of said first micro cell and with said anode of said second micro cell to realize a common diffusion chamber for the fuel of said first micro cell a of said second micro cell.

Abstract: A power generator has a hydrogen producing fuel and a fuel cell having a proton exchange membrane separating the hydrogen producing fuel from ambient. A valve is disposed between the fuel cell and ambient such that water is controllably prevented from entering or leaving the fuel cell by actuation of the valve. In one embodiment, multiple fuel cells are arranged in a circle around the fuel, and the valve is a rotatable ring shaped gate valve having multiple openings corresponding to the fuel cells.

Abstract: Processes to shut down a fuel cell system are described. In one implementation (400), fuel (H2) and oxidizer (air) flow is halted and the system's anode region (305) is sealed. A load (215) is then engaged across the system's fuel cell stack (205) so as to deplete much of the fuel in the stack's sealed anode region (305). The stack (205) is monitored to determine when the load should be disengaged. (215). Once the load is disengaged, fluid communication between the system's anode and cathode regions is established. The vacuum created in the anode region (305) as a consequence of consuming H2 therein, pulls nitrogen enriched gas from the cathode region (310) into the anode region (305). When substantially all of the H2 has been depleted from the anode region (305), no pressure difference exists between the anode and cathode regions and fluid communication between the two is severed.

Abstract: In a first aging step, a plus electrode electric potential is applied to an anode of a fuel cell, and a minus electrode electric potential is applied to a cathode of the fuel cell. In this state, hydrogen pump operation is performed at maximum current density in use by supplying humidified hydrogen to the anode without supplying any oxygen-containing gas to the cathode. Thus, the hydrogen passes through a solid polymer electrolyte membrane toward the cathode. After the first aging step, in a second aging step, power generation of the fuel cell is performed at the maximum current density.

Abstract: The invention provides the use of silicon particles as redox catalyst, an electrochemical device and method thereof. As electrocatalyst, the silicon particles catalyze a redox reaction such as oxidization of the redox reactant such as renewable fuels e.g. methanol, ethanol and glucose. The device such as a fuel cell comprises a redox reactant and a catalytic composition comprising silicon nanoparticles. The silicon particles catalyze the redox reaction on an electrode such as anode in the device. In preferred embodiments, the electrocatalysis is dramatically improved under low illuminance such as in darkness. The invention can be widely used in applications related to for example a fuel cell, a sensor, an electrochemical reactor, and a memory.

Abstract: Fuel cell systems including a fuel composition are disclosed. In some embodiments, a fuel composition includes an organic polymer, and a fuel such as methanol, and the composition has a hardness of at least about 2 grams peak force, as determined by penetration test using a texture analyzer.

Abstract: This invention provides a moving object having a fuel cell system, which is capable of preventing the entry of fuel gas into a cabin even if the leakage of the fuel gas occurs. The moving object, having the fuel cell system (1), has an air introduction mechanism (5) for introducing air from the outside of the moving object into a cabin space inside the moving object, wherein an air introduction port (50) for the air introduction mechanism (5) is formed a given distance apart from the fuel cell system (1), so that gas leaking from the fuel cell system (1) does not reach the air introduction port (50).

Abstract: A fuel storage device for fuel cell comprises a tank-in-tank or tank-by-tank type tank. In addition, a pipe-in-pipe or pipe-by-pipe delivery system is also provided. A fuel cell system using the fuel storage device comprises liquid fuel at the anode side, liquid oxidant at the cathode side, electrolyte, fuel and oxidant tank-in-tank storage system, fuel and oxidant pipe-in-pipe deliverable system, and by-products handling at both the anode and cathode sides. The liquid fuels include amine-based compounds such as hydrazine, hydroxyl amine, ammonia, and their derivatives.

Abstract: Anode catalysts for conversion of hydrocarbon feeds in solid oxide fuel cell membrane reactors. An anode catalyst may be a mixture of a metal with a metal oxide, for example a mixture of copper or copper-nickel alloy or copper-cobalt alloy with Cr2O3. Mixed oxides can be prepared by dissolving into water soluble salts of the different metals, chelating the metal ions with a chelating agent, neutralizing the solution, removing water by evaporation to form a gel which then is dried, and finally heating the dried gel to form a mixed oxide of the different metals. The chelating agent can be citrate ions, and ammonia can be added to the solution until the pH of the solution is about 8. The mixed oxide so formed then is reduced, for example by hydrogen, to form a composite comprising the metal (Cu, Cu—Co, Cu—Ni) and metal oxide, here Cr2O3.