Abstract: A fuel cell system (10) basically containing an energy storage subunit (14) which receives feed fuel (17) or recirculated fuel (23) both containing H2 where either fuel is contacted with a metal in the energy storage subunit (14) to provide a H2 rich fuel (18) to a fuel cell power generator (20) that is completely separated from all other components such as possible reformers (13), thermal energy sources (16) and storage media subunits (24, 35).

Abstract: The present invention is a solid oxide fuel cell device with a load following function for changing a fuel supply rate in response to a load defined as a required power determined by demand power.

Abstract: An arrangement for charging a substrate reservoir for boats or underwater boats when traveling at the surface, comprising an energy source which is either a propulsion system driven with fossil fuels or a nuclear-powered propulsion system, and a DC current generator operated therewith; a reservoir tank for distilled or deionized water; an electrolyzer for conversion of the water from the reservoir tank with the DC current from the energy source to hydrogen and oxygen; a chemical reactor for production of a high-energy form of the substrate having an extensive ?-conjugated system by chemical reaction by means of hydrogen; and a storage means for the high-energy form of the substrate produced in the reactor.

Abstract: A system for fabricating a fuel cell component in which a deposition mechanism deposits loading material particles onto the fuel cell component and an actuation mechanism actuates the deposition mechanism. A unit provides a tape fixing agent to the fuel cell component and loaded material particles so as to retain the particles on the fuel cell component. Other fuel components are retained to the fuel cell component also using a tape fixing agent.

Abstract: The present invention comprises individual fuel cells 84 disposed within a fuel cell module 2; a reformer 20; a reformer temperature sensor 148 and generating chamber temperature sensor 142 for detecting the reforming state temperature inside the reformer, and a control section 110 for controlling the fuel cell module operation. In a state whereby a stopping of fuel cell module operation has been executed from a high temperature, this control section skips the normal startup ATR and executes a restart control by the SR when the reforming state temperature is within the normal startup ATR temperature band and a restart of operation has been executed.

Abstract: To provide a solid oxide fuel cell system with which the durable lifespan of the reformer can be extended by suppressing temperature unevenness in the reformer. The present invention is a solid oxide fuel cell, including a fuel cell module, a reformer for producing hydrogen by POX, ATR, and SR steps; a fuel supply apparatus, a reform air supply apparatus, a water supply apparatus, a generating air supply apparatus, and a control device which, as the temperature inside the fuel cell module rises, executes in sequence POX, ATR and SR steps at predetermined respective temperature bands, and causes a rise in temperature at which electrical generation is possible; wherein the control device comprises a localized temperature rise suppression circuit which, by causing steam reforming to occur locally within the reformer in the POX step, suppresses localized temperature rises in the reformer.

Abstract: The present invention relates to a fuel processing unit in an electrochemical fuel cell power plant, and more specifically to a preheater combustor that forms byproduct compounds that may destroy downstream catalytic reactors for fuel reforming. The present invention includes a retention material that collects the byproduct compounds prior to entry into the downstream reactors. The retention material may be comprised of at least one active compound and a support structure, preferably having a porous body to facilitate tortuous fluid flow. Further aspects of the invention may include an electrical charging device for use with the retention device material that enhances collection of byproduct compounds. The present invention also includes a method of operation for start-up incorporating a retention material.

Abstract: A fuel cell system for use with an endothermic fuel generator including a fuel cell stack having a primary fuel cell stack having a first thermal mass and a secondary fuel cell stack having a second thermal mass smaller than the first, the fuel cell system further including a first thermal coupling mechanism configured to thermally couple waste heat from the secondary fuel cell stack to the primary fuel cell stack, and a second thermal coupling mechanism configured to thermally couple waste heat from the fuel cell stack to the endothermic fuel generator.

Abstract: A catalyst for a fuel cell includes an active metal catalyst and a composite supporter supporting the active metal catalyst. The composite supporter includes a spherical-shaped supporter and a fibrous supporter, wherein the fibrous supporter is included in an amount of about 5 wt % to about 40 wt % based on the total amount of the composite supporter. In addition, an electrode for a fuel cell using the same, a membrane-electrode assembly for a fuel cell including the electrode, and a fuel cell system including the membrane-electrode assembly are also disclosed.

Abstract: A catalyst for a fuel cell includes an active metal catalyst and a composite supporter supporting the active metal catalyst. The composite supporter includes a spherical-shaped supporter and a fibrous supporter, wherein the fibrous supporter is included in an amount of about 5 wt % to about 40 wt % based on the total amount of the composite supporter. In addition, an electrode for a fuel cell using the same, a membrane-electrode assembly for a fuel cell including the electrode, and a fuel cell system including the membrane-electrode assembly are also disclosed.

Abstract: A fuel cell system includes a fuel cell stack, an oxidizer supply unit, a reformer, a fuel tank, and a water tank. The reformer generates a hydrogen-containing reformed gas reformed from hydrocarbon-based fuel and supplies it to the fuel cell stack. The fuel tank supplies the hydrocarbon-based fuel to the reformer. The water tank supplies water to the reformer. The reformer includes a reforming unit configured to have a reforming reaction generated therein, a combustion unit configured to supply heat energy to the reforming unit, and a carbon monoxide reduction unit configured to reduce the concentration of carbon monoxide in a reformed gas discharged from the reforming unit. A combustion gas pipe is connected to the combustion unit. A reformed gas pipe is disposed between the reforming unit and the carbon monoxide reduction unit.

Abstract: A power generating system of the present invention includes: a package (70); a power generator (1); a combustible gas passage (23); a first device configured to operate by a first voltage using a DC power generated by the power generator (1); a second power supply circuit (13) configured to generate the DC power of the first voltage; a first connecting unit (8) arranged between the first device and the second power supply circuit (13); a control circuit (7) configured to control the first device using the DC power of the first voltage; and a first power supply circuit (11) configured to generate a power of a second voltage higher than the first voltage, and the package (70) is divided by a dividing wall (71) into a first space (72) in which the power generator (1), the combustible gas passage (23), the first device, the first connecting unit (8), and the control circuit (7) are arranged and a second space (73) in which the first power supply circuit (11) and the second power supply circuit (13) are arranged.

Abstract: Provided is a fuel-cell system and a method of operating the fuel-cell system, wherein functions F=f(P) and P=f?1(F) of electrical output P and fuel flow-rate F required to output P are beforehand obtained, and a reformable fuel flow-rate FR is calculated from the temperature of reforming catalyst layer. When FR?Fmin, if the output demand PD?maximum output PM, and when f(PD)?FR, F is set to f(PD); and when f(PD)>FR, the P is set to the maximum value within a range of less than PD amongst P calculated from P=f1(FR), and F is set to FR. When PD>PM, and when f(PM)?FR, the cell output is set to PM, and F is set to f(PM). When f(PM)>FR, the cell output is set to the maximum value amongst P calculated from P=f1(FR), and F is set to FR.

Abstract: Method of operating a fuel cell apparatus in which a reforming reaction in the reforming portion is selected by a controller at the starting time of the apparatus by comparing a first starting temperature of a reforming portion to a temperature T1 at which steam reforming can be performed and comparing a second starting temperature of a vaporizing portion to a temperature T2 at which a predetermined amount of steam can be generated by steam reforming. A reforming reaction starting with an autothermal reforming reaction is performed when the first starting temperature is not lower than T1 and the second starting temperature is lower than T2.

Abstract: A fuel cell system includes a plurality of fuel cells arranged into a stack. A combustor receives a cathode exhaust flow from the fuel cell cathodes and a flow of fuel. The fuel is oxidized in the combustor by the cathode exhaust to produce a mixed exhaust flow. A cathode air flow path extends between a fresh air source and the fuel cell cathodes. An air preheater is arranged along the cathode air flow path, cathode air passing through the air preheater being heated therein by a flow of uncombusted anode exhaust from the fuel cell anodes. A cathode recuperator is arranged along the cathode air flow path, cathode air passing through the cathode recuperator being heated therein by the mixed exhaust flow. Water passing through a vaporizer is converted to steam by heat from the mixed exhaust flow and directed from the vaporizer to the fuel cell anodes.

Abstract: Embodiments of the invention provide an ammonia operated fuel cell system including an alkaline membrane fuel cell (AMFC) having an anode, and an ammonia thermal cracker including a combustion chamber, the cracker being in gas communication with an ammonia source, and configured to provide a supply of H2 directly to the AMFC anode.

Abstract: A fuel cell system includes a reformer that generates reformed gas using reforming fuel; a fuel cell that generates electric power using the reformed gas generated by the reformer; and a control device. The control device includes a plurality of different stop control modes for stopping operation of the fuel cell system, and selects a specific stop control mode among the plurality of stop control modes, according to the cause of a malfunction of the fuel cell system.

Abstract: The present invention provides a fuel cell system, and the fuel cell system comprises a fuel cell, an after burner, a heat exchanger and a reformer. The after burner connects with the fuel cell to receive rest-bar of the fuel cell and produce a gas with high temperature. The heat exchanger comprises a first heat exchanging unit and a second heat exchanging unit connected with the first heat exchanging unit, and the second heat exchanging unit connects with a fuel input pipe for receiving the fuel. The reformer connects with the after burner, the first heat exchanging unit and the second heat exchanging unit separately.

Abstract: A fuel cell system includes a reforming unit, a carbon monoxide decreasing unit, a fuel cell, a burner unit, a raw gas supply device, and a heating unit. The heating unit is controlled at a start-up operation of the fuel cell system, so as to adjust an amount of a desorbed raw gas desorbed out of components of the raw gas adsorbed to at least one of a reforming catalyst and a carbon monoxide decreasing catalyst such that a ratio of an amount of combustion air to an amount of a raw gas in the burner unit falls within a predetermined range.

Abstract: Disclosed herein is a separator for a molten carbonate fuel cell, the separator including four steel sheets in which edges of the four steel sheets are joined to each other thereby providing three spaces therebetween, comprising a cathode channel, serving as a flow path of oxidant gas, formed in the first space; an anode channel, serving as a flow path of fuel gas, formed in the second space such that the anode channel is separated from the cathode channel; and a fuel gas reforming channel formed in the third space, which is located between the first space and the second space. The separator for a molten carbonate fuel cell is advantageous in that the volume of the fuel cell is decreased, and the structure thereof is simple, thus reducing the production cost thereof.

Abstract: A hydrogen generator of the present invention includes a reformer (16) for generating a hydrogen-containing gas through a reforming reaction using a raw material; a combustor (102a) for heating the reformer (16); a combustion air supplier (117) for supplying combustion air to the combustor (102a); and an abnormality detector (110a) for detecting an abnormality; and a controller (110) configured to control the combustion air supplier (117) such that the reformer (16) is cooled with a higher rate in an abnormal shut-down process executed after the abnormality detector (110a) detects the abnormality, than in a normal shut-down process.

Abstract: Anodes utilizing precise energy separation are provided. The anodes can be used to generate electrical energy from a feedstock via precise energy separation. The anodes include an energy source that supplies the promoter energy to target molecules in a feedstock to dissociate one or more target bonds in one or more target molecules. Generally, the energy is provided in an effective amount, intensity, and frequency of energy to specifically dissociate one or more target bonds in one or more target molecule present in the feedstock, releasing electrons. These electrons are accepted by an electrode that is electrically connected to an electron sink. Fuel cells containing anodes utilizing precise energy separation are provided.

Abstract: To provide a solid oxide fuel cell device capable of smooth transition from a startup state to an electrical generating state. The present invention is a solid oxide fuel cell device (1) for generating electricity, having a fuel cell module (2); a reformer (20) for reforming fuel, heated by the combustion of remaining fuel not used in the generation of electricity; a fuel supply means (38); a water supply means (28); an electrical generation oxidant gas supply means (45); and a control means (110) for controlling the fuel supply means and water supply means at the time of startup when the solid oxide fuel cell units are raised to a temperature at which electrical generation is possible; wherein the control means controls the fuel supply means during the SR operation such that electrical generation is started after reducing the fuel supply flow rate prior to starting electrical generation.

Abstract: A fuel cell system having a hydrogen supply path for supplying a hydrogen gas to a fuel cell, an injector which is provided in the hydrogen supply path and which regulates the pressure of the gas on the upstream side of the hydrogen supply path to inject the pressure-regulated hydrogen gas to the downstream side of the hydrogen supply path, and a surge tank 81 which is provided in the hydrogen supply path on the upstream side from the injector and which suppresses the fluctuation of the pressure of the gas in the hydrogen supply path.

Abstract: Apparatus and operating methods are provided for controlled atmosphere furnace systems. In one possible embodiment, hydrogen is injected from a hydrogen source to an enclosure. The hydrogen is circulated within the enclosure from a gas inlet to a gas outlet. A temperature is raised within the enclosure to a predetermined threshold. Hydrogen is pumped from the gas outlet to the gas inlet with an electrochemical hydrogen pump. The electrochemical hydrogen pump has a first electrode in fluid communication with the gas outlet, and a second electrode in fluid communication with the gas inlet. An electrical potential is provided between the first and second electrodes, wherein the first electrode has a higher electrical potential with respect to zero than the second electrode. Various methods, features and system configurations are discussed.

Abstract: A casing of a fuel cell system is divided into a fluid supply section, a module section, and an electrical equipment section. A detector, a fuel gas supply apparatus, an oxygen-containing gas supply apparatus, and a water supply apparatus are provided in the fluid supply section. A fuel cell module and a combustor are provided in the module section. A power converter and a control device are provided in the electrical equipment section. The module section is interposed between the fluid supply section and the electrical equipment section.

Abstract: A method of operating a hydrogen generator includes: a step (a) of generating a hydrogen-containing gas by a hydrogen generation unit by using a raw material in the hydrogen generation unit; a step (b) of removing a sulfur compound from the raw material by a hydrodesulfurizer which is heated by heat transferred from the hydrogen generation unit; and a step (c) of performing an operation of supplying the raw material to the hydrogen generation unit after stopping the generating of the hydrogen-containing gas by the hydrogen generation unit. The step (c) is not performed unless, at least, a temperature of the hydrodesulfurizer is such a temperature at which carbon deposition from the raw material is suppressed.

Abstract: When terminating power generation by a fuel cell 3 in a fuel cell system 1, an amount of a raw fuel material introduced to a reforming catalyst 2a of a reformer 2 is reduced. Here, before the temperature of the reforming catalyst 2a is lowered to the un-reformed gas generation temperature, an amount of water supplied to the reforming catalyst 2a is controlled to increase the temperature of the reforming catalyst 2a. Thus, upon termination of power generation in the fuel cell 3, no un-reformed gas is generated and the reformed gas is supplied to the fuel cell 3.

Abstract: In certain embodiments of the present disclosure, a proton exchange membrane fuel cell is described. The fuel cell includes a twin-cell electrochemical filter. A flow of reformate H2 and pulse potential are switched between each respective filter cell such that when CO-contaminated H2 is fed to one filter cell, generally simultaneously a pulse potential is applied to the other filter cell.

Abstract: A fuel cell comprises an anode, a cathode, and a proton exchange membrane. The anode and cathode can include a catalyst layer which includes a plurality of generally aligned carbon nanotubes. Methods of making a fuel cell are also disclosed.

Abstract: A fuel cell module includes a vaporizer; a reformer; a cell stack; and a housing which accommodates in inside thereof the vaporizer, the reformer, and the cell stack and includes in inside thereof a wall portion defining an exhaust gas flow channel, wherein the wall portion comprises an inner wall portion; and an outer wall portion, and defines the exhaust gas flow channel communicating to the accommodation chamber between the inner wall portion and the outer wall portion, and the vaporizer is disposed in the exhaust gas flow channel at a position below the reformer and the cell stack so that the vaporizer is spaced from the reformer, and further, spaced from the outer wall portion.

Abstract: A fuel cell system includes a fuel cell module and a control device. The control device includes a partial oxidation reformer adjuster, a combustion starter, and a power generator. Based on at least any of the reforming state in the partial oxidation reformer, the combustion state in the exhaust gas combustor and the temperature of the fuel cell stack, the partial oxidation reformer adjuster adjusts the temperature of the partial oxidation reformer, the supply amount of raw fuel, and the supply amount of oxygen-containing gas, the combustion starter starts combustion in the exhaust gas combustor, and the power generator starts power generation in the fuel cell stack.

Abstract: A casing of a fuel cell system is divided into a first fluid supply section, a second fluid supply section, a module section, and an electrical equipment section. A water supply apparatus, a fuel gas supply apparatus, and a detector are provided in the first fluid supply section. An oxygen-containing gas supply apparatus is provided in the second fluid supply section. A fuel cell module and a combustor are provided in the module section. A power converter and a control device are provided in the electrical equipment section. The module section is interposed between the first fluid supply section and the electrical equipment section. The second fluid supply section is disposed on the lower surface of the module section.

Abstract: The present disclosure is directed to systems and methods for maintaining hydrogen-selective membranes during periods of inactivity. These systems and methods may include heating and maintaining at least the hydrogen-selective membrane of a hydrogen-producing fuel processing system in a thermally buffered state and/or controlling the chemical composition of the gas streams that may come into contact with the hydrogen-selective membrane. Controlling the chemical composition of the gas streams that may come into contact with the hydrogen-selective membrane may include maintaining a positive pressure of an inert, blanket, reducing, and/or non-oxidizing gas within the membrane separation assembly and/or periodically supplying a reducing gas stream to the membrane separation assembly.

Abstract: When terminating power generation by a fuel cell 3 in a fuel cell system 1, an amount of a raw fuel material introduced to a reforming catalyst 2a of a reformer 2 is reduced. Here, before the temperature of the reforming catalyst 2a is lowered to the un-reformed gas generation temperature, an amount of water supplied to the reforming catalyst 2a is controlled to increase the temperature of the reforming catalyst 2a. Thus, upon termination of power generation in the fuel cell 3, no un-reformed gas is generated and the reformed gas is supplied to the fuel cell 3.

Abstract: A hydrogen generation apparatus including: a first desulfurizer; a second desulfurizer; a reformer to generate a hydrogen-containing reformed gas from a raw material gas from which sulfur has been removed by at least one of the first desulfurizer and the second desulfurizer; and a recycle passage through which a part of the reformed gas generated by the reformer is mixed into the raw material gas to be supplied to the second desulfurizer. After installation or maintenance of the hydrogen generation apparatus, the raw material gas is supplied to the reformer through the first desulfurizer until a catalyst in the second desulfurizer is activated by a mixed gas of the reformed gas supplied through the recycle passage and the raw material gas, and after the catalyst in the second desulfurizer is activated, the raw material gas is supplied to the reformer through the second desulfurizer.

Abstract: Apparatus and operating methods are provided for controlled atmosphere furnace systems. In one possible embodiment, hydrogen is injected from a hydrogen source to an enclosure. The hydrogen is circulated within the enclosure from a gas inlet to a gas outlet. A temperature is raised within the enclosure to a predetermined threshold. Hydrogen is pumped from the gas outlet to the gas inlet with an electrochemical hydrogen pump. The electrochemical hydrogen pump has a first electrode in fluid communication with the gas outlet, and a second electrode in fluid communication with the gas inlet. An electrical potential is provided between the first and second electrodes, wherein the first electrode has a higher electrical potential with respect to zero than the second electrode. Various methods, features and system configurations are discussed.

Abstract: The present invention is a niobium nitride which has a composition represented by the composition formula Nb3N5 and in which a constituent element Nb has a valence of substantially +5. The method for producing the niobium nitride of the present invention includes the step of nitriding an organic niobium compound by reacting the organic niobium compound with a nitrogen compound gas.

Abstract: The invention provides a solid oxide fuel cell generation system and a start up method thereof which heat up a reformer and a cell main body without any water and nitrogen gas, and start up for a short time until a power generation and without deteriorating a reliability of the cell. In a solid oxide fuel cell generation system having a power generation cell including an anode, a cathode and a solid electrolyte membrane, a mixing portion for obtaining a mixed gas by mixing a used fuel gas discharged from the anode with a raw fuel, a reducing combustion gas generating apparatus, and a reforming portion, the reducing combustion gas generating apparatus has a starting burner generating a reducing combustion gas, and the mixing portion, the reducing combustion gas generating apparatus, the reforming portion and the anode are coupled alphabetically from an upstream side.

Abstract: A reformer including a vaporization part provided with a supply port through which raw fuel is supplied, the supply port being provided at a central section of a tubular container; and reforming parts provided at both sides of the container, each reforming part containing reforming catalyst that reforms the raw fuel that flows into the reforming part from the vaporization part into fuel gas and provided with a fuel-gas supply port through which the fuel gas is discharged.

Abstract: A fuel cell sealing plate taking-out method that may include taking out a sealing plate from a stack of sealing plates one by one while an air layer exists between adjacent sealing plates of the stack of fuel cells. A protrusion may be formed beforehand at one or more surfaces of each sealing plate. Due to the air layer existing between adjacent sealing plates, it may be possible to take out the sealing plate one by one from the stack of sealing plates.

Abstract: The present invention relates to processes and apparatuses for generating electrical power from certain non-gaseous carbonaceous feedstocks through the integration of catalytic hydromethanation technology with fuel cell technology.

Abstract: A fuel cell system includes a fuel cell stack having an anode plate and a cathode plate arranged on opposing sides of a proton exchange membrane. Cooling channels are in thermal contact with at least one of the anode plate and the cathode plate and include an internal coolant passage. A pressure-drop device is provided in the coolant channels and is configured to provide a sub-atmospheric pressure within the coolant passage. In one example, the coolant within the coolant passage is at less than ambient pressure. A compression device fluidly interconnects to and is downstream from the internal coolant passage by a coolant system loop and configured to convey a sub-atmospheric pressure coolant steam. The compression device is configured to increase the pressure and a temperature of the sub-atmospheric coolant steam to a super-atmospheric pressure and maintain the coolant steam within a steam region of a pressure-enthalpy curve.

Abstract: The present invention is directed to a solid oxide fuel cell system with a load following function. The system sets a command power value, based on the amount of load, and instructs an inverter to achieve a permitted power value corresponding to the command power value, which is a permitted amount of power to be extracted from the fuel cell system. The system also changes an amount of change per unit time in the next inverter permitted power value.

Abstract: Disclosed are an electrode for a fuel cell that includes an electrode substrate and a surface-treatment layer disposed on the electrode substrate and including a hydrophilic layer and a hydrophobic layer partially disposed on the hydrophilic layer. Also disclosed are a method of fabricating an electrode for a fuel cell, a membrane-electrode assembly, and a fuel cell system including the membrane-electrode assembly.

Abstract: A fuel cell system includes a fuel processor; a fuel cell stack; a first water tank; a combustor; a water discharge passage connected to a water drain port formed in the first water tank to discharge the water from inside of the first water tank; a water filling detector configured to detect that at least one of the water drain port and the water discharge passage is filled with water; a water supply unit for supplying the water to the first water tank; and a controller configured to execute a water filling step of supplying the water to the first water, supply the combustible gas to the combustor via the first water tank and cause the combustor to combust the combustible gas, when the water filling detector detects that at least one of the water drain port and the water discharge passage is filled with water.

Abstract: A fuel reformer includes a primary carrier having a chamber between two separated protrusions for receiving a fuel material, two orifices formed in the protrusions, and two apertures communicative with the chamber of the primary carrier, and a secondary carrier disposed below the primary carrier and having a compartment formed between two separated swellings for receiving a regulating fluid and having two holes formed in the swellings and communicative with the apertures of the primary carrier, and the orifices of the protrusions are communicative with the compartment of the secondary carrier for allowing the regulating fluid to flow through the orifices of the primary carrier and the compartment of the secondary carrier.

Abstract: A process is provided for operating a fuel cell system (1), especially in a motor vehicle, wherein the fuel cell system (1) includes at least one reformer (2) and at least one fuel cell (3). To prolong the service life of the system (1), a warm-holding mode is carried out after switching off the fuel cell system (1). During the warm-holding mode an educt containing hydrogen and carbon monoxide is fed to the reformer (2) and reacted with air in reformer (2) at a catalyst (5) of reformer (2) in an exothermal reaction.

Abstract: A fuel cell system includes: a fuel cell; a fuel gas supply unit; an oxidizing gas supply unit; an oxidizing gas supply passage; an oxidizing gas discharge passage; an oxidizing gas branch passage; an on-off valve disposed on at least one of the oxidizing gas discharge passage and a portion of the oxidizing gas supply passage; an oxidizing gas supply amount measuring unit disposed on the oxidizing gas branch passage; and a controller configured to determine that the on-off valve is normal in a case where a supply amount of the oxidizing gas measured by the oxidizing gas supply amount measuring unit is equal to or larger than a first threshold and determines that the on-off valve is abnormal in a case where the supply amount of the oxidizing gas measured by the oxidizing gas supply amount measuring unit is smaller than the first threshold.

Abstract: A mesoporous oxide-catalyst complex including: a mesoporous metal oxide; and a catalyst metal supported on the mesoporous metal oxide, wherein the catalyst on the mesoporous metal oxide has a degree of dispersion of about 30 to about 90 percent.