Abstract: The invention relates to a process for producing a catalytic component on a metallic or ceramic support for a fuel cell system, in which the catalytic component is applied to the metallic or ceramic support in at least one layer. This at least one layer contains at least one hydrophobic material component, which is applied together or alternately with at least one catalytically active material component in one process step. The invention also relates to a catalytic component, which is applied to a metallic or ceramic support, for a chemical reactor in a fuel cell system, and to methods of using the catalytic component.

Abstract: Integrated power systems and methods for use in an electric vehicle having a fuel cell and an electric motor, the integrated power systems and methods including a common casting, a traction inverter module operable for converting DC current generated by the fuel cell into AC current capable of powering the electric motor, and a DC/DC converter operable for stepping-down the voltage of the fuel cell. The traction inverter module and the DC/DC converter are disposed within the common casting.

Abstract: An electrochemical cell stack comprises a plurality of membrane electrode assemblies interposed between pairs of separator plates. The stack comprises adhesively bonded layers. Preferably each membrane electrode assembly is adhesively bonded to the adjacent pair of separator plates. The adhesive bond between the plate and membrane electrode assembly preferably provides a substantially gas and liquid-tight seal around the perimeter of the electrochemically active area of the membrane electrode assembly and around any fluid manifold openings formed therein. Alternatively, or in addition, adjoining pairs of separator plates in an electrochemical cell stack may be adhesively bonded together. Such pairs of adhesively bonded plates may define cooling spaces between neighboring cells. Stacks comprising a plurality of individual cell modules may be formed, each module comprising a membrane electrode assembly bonded to a pair of separator plates.

Abstract: A method detects fluid leaks within a fuel cell assembly. The method comprises (a) introducing a first supply fluid to a first fluid passage within the fuel cell assembly, wherein the first supply fluid comprises a tracer; (b) introducing a second supply fluid to a second fluid passage within the fuel cell assembly, wherein in the absence of a leak in the first fluid passage, the second fluid passage is fluidly isolated from the first fluid passage; and (c) monitoring a second fluid exhaust stream exiting from the second fluid passage and detecting when a concentration of the tracer is present within the second fluid exhaust stream.

Abstract: A method and apparatus for controlling a permanent magnet synchronous motor (8) coupled to a turbo engine such that transient current and steady state current are minimized. The method comprises the steps of, for a given DC bus voltage, determining an acceleration profile as a function of a voltage-offset value, a low-speed rated speed value, a high-speed rated speed value, a first desired speed for warming up the turbo engine, and a second desired speed where the turbo engine has sufficient torque to accelerate to its rated speed without the aid of the permanent magnet synchronous motor (8).

Abstract: A DC bus for use in a power module has a positive DC conductor bus plate parallel with a negative DC conductor bus plate. One or more positive leads are connected to the positive bus and are connectable to a positive terminal of a power source. One or more negative leads are connected to the negative bus and are connectable to a negative terminal of a power source. The DC bus has one or more positive connections fastenable from the positive bus to the high side of a power module. The DC bus also has one or more negative connections fastenable from the negative bus to the low side of the power module. The positive bus and negative bus permit counter-flow of currents, thereby canceling magnetic fields and their associated inductances, and the positive and negative bus are connectable to the center portion of a power module.

Abstract: A method of ceasing operation of an electric power generation system improves the cold start capability and freeze tolerance of a fuel cell stack by reducing the amount of water remaining within the passages of the stack. The method involves purging one or more of the fuel cell stack oxidant and fuel passages at shutdown prior to allowing the fuel cell stack to drop to temperatures below the freezing point of water. Preferably purging at shutdown is conducted at a temperature below the stack operating temperature.

Abstract: Application of two-dimensional materials (TDMs) that are exfoliated transition metal dichalcogenides in electrochemical fuel cells to remove contaminants that are harmful to the fuel cells; to effect proper transport and containment of various fluids in fuel cells to achieve proper and efficient operation; to protect various surfaces and materials commonly comprised in or used for fuel cells and critical to their operation; and to purify and lower the freezing point of cooling water used for the fuel cell stacks. Disclosed are methods whereby the TDM is used as a barrier to prevent unwanted crossover (between electrodes through a polymer electrolyte membrane or PEM) of chemical species; where the TDM is used to coat and/or encapsulate catalyst particles, carbon catalyst support, PEMs, and chemical or metal hydrides, to protect the same from unwanted exposure to chemical species; and where the TDM is used to purify and lower the freezing point of fuel cell stack cooling water.

Abstract: A method of detecting transfer leaks within a solid polymer electrolyte fuel cell stack comprises: supplying fuel or inert gas to the oxidant manifold(s) of the stack at a first pressure; supplying the other of fuel or inert gas to the fuel manifold(s) at a second pressure greater than or equal to the first pressure; optionally supplying fuel to the coolant manifold(s) at a third pressure; applying a potential difference across at least one of the fuel cell assemblies; and measuring the transfer current across the fuel cell assembly or assemblies. A corresponding apparatus detects transfer leaks within solid polymer electrolyte fuel cells stacks.

Abstract: An electrochemical fuel cell is operated with periodic reactant starvation at either or both electrodes. Periodic reactant starvation conditions cause a change in the potential of the starved electrode and may result in the removal of electrocatalyst poisons and in improved fuel cell performance. This technique may have other beneficial effects at the electrodes, including performance improvements due to water management effects or localized heating effects at the starved electrode. In a preferred method, while successive localized portions of a fuel cell electrode are periodically reactant starved, the remainder of the fuel cell electrode remains electrochemically active and saturated with reactant such that the fuel cell is able to continue to generate power.

Abstract: A process for producing a compact catalytic reactor, in which reaction spaces or heat-transfer spaces are formed by stacking at least partially structured plates alternately one on top of the other, a catalyst is introduced into the reaction spaces, and the plates are provided with a layer of solder at least in the edge region, but not in the region provided with catalyst material, and, after stacking them one on top of the other, are soldered to form a reactor. In addition, the plates may be provided with a bent-up edge region a for easy positioning and for increasing the leak tightness. Finally, an unstructured intermediate plate may also be respectively provided between the structured plates.

Abstract: In one embodiment, a harmonic feedback system is characterized by: a three-phase to two-phase transformer configured to convert an output fundamental frequency current from a distributed power system and to convert the output fundamental frequency current from a three-phase current to a two-phase stationary reference current; a harmonic frequency transformer configured to convert the two-phase stationary reference current to a synchronous reference current, said harmonic frequency transformer having a target synchronous reference frame frequency based upon a reference harmonic current of the output fundamental frequency current; at least one filter device configured to remove predetermined components from the synchronous reference current to output a harmonic feedback current; a summation component to compare the harmonic feedback current with the reference harmonic current and to output a harmonic error current for driving the distributed power system to produce the output current.

Abstract: A supported catalyst composition comprising a metal catalyst nanodispersed in a support that is a hard disordered carbon or carbon glass; or a partially graphitized or disordered carbon intercalation complex; or “house-of-cards” transition metal dichalcogenide such as molybdenum disulfide (MoS2). Also disclosed are embodiments based on the above supported catalyst compositions, wherein the metal catalyst is Pt or Pt alloy, and wherein the “pores” comprised in the support are engineered to provide selective access to H2, but not to larger molecules, such as CO or H2O. Disclosed are methods for improving catalyst utilization, resistance to poisoning, and resistance of catalyst supports to corrosion-as well as products related thereto. Also disclosed is an MEA that comprises the supported, nanodispersed Pt and Pt alloy catalyst compositions of this invention, and a fuel cell that contains such an MEA.

Abstract: In a method of producing microstructured metal sheets, microstructures are made in a metal sheet surface in a continuous embossing step on one side of the metal sheet, while the surface structure of the other side is essentially not changed. The embossing step is carried out by means of an embossing roller which has a negative of the microstructure to be embossed. The flanks of the microstructure form an angle of at least 5° with respect to the perpendicular line, and the negative contains compensating structures in the regions surrounding the microstructure for rendering the forming uniform along the roller slit.

Abstract: The present invention relates to improving the overall efficiency of a fuel cell system by reducing parasitic power consumption. A controller is programmed to decrease oxidant stoichiometry until oxidant starvation is detected or until oxidant stoichiometry is about one. When oxidant starvation is detected, the oxidant stoichiometry is increased until oxidant starvation is no longer detected. The fuel cell system employs a sensor for detecting an operational characteristic such as voltage output, or oxygen or hydrogen concentration in the cathode exhaust stream. The controller uses the operational characteristic to calculate oxidant stoichiometry or to determine when there is oxidant starvation at the cathode.

Abstract: This invention provides a process for determining a desired torque (load) value for a load-dependent current generating system, such as a fuel cell system, in an electric vehicle. The process calculates load based on various driver demands such as accelerator position, brake position, Key on/off, Gear selector position, and system component temperatures. Additionally, the process considers the amount of current available from the load-dependent current generating system and matches that current to the current drawn by the electric motor. The process can be applied to a direct current (DC) electric traction motor or an alternating current (AC) induction motor.

Abstract: In an improved electrochemical fuel cell assembly, a reactant flow path extends substantially linearly across the electrochemically active area of an electrode. The electrode has an in-plane nonuniform structure in its electrochemically active area as the active area is traversed in the direction of the substantially linear reactant flow path. Embodiments in which the structure of the fuel cell electrode varies substantially symmetrically along the reactant flow path are particularly preferred in fuel cells in which the flow direction of a reactant is periodically reversed.

Abstract: A system is used for cooling a fuel cell arrangement, particularly a fuel cell arrangement with a gas generating system in a motor vehicle. A coolant circuit for the system is connected to a cooler, a coolant delivery device, a fuel cell and at least another component to be cooled. The coolant circuit has at least two valve devices which are each assigned to the fuel cell and the at least another component to be cooled. By means of the valve devices, a flow rate of the coolant through the fuel cell or the another component to be cooled can be influenced as a function of the temperature in the region associated with the fuel cell or the another component.

Abstract: An autothermal reformer for converting a fuel into a reformate stream comprising hydrogen comprises (a) a closed vessel having a top end and a bottom end, the vessel comprising at least one insulation layer adjacent the interior surface of the vessel; (b) a first reactant manifold disposed within the vessel for receiving and distributing a first reactant stream, the first reactant manifold having a plurality of mixer tubes extending therefrom, each of the mixer tubes having an inlet end and an outlet end, the mixer tubes disposed in a separator member; and (c) a second reactant manifold disposed within the vessel for receiving and distributing a second reactant stream, the second reactant manifold comprising a plurality of injection tubes. Each of the injection tubes has an inlet end and an outlet end, extend through the first reactant manifold and are fluidly isolated therefrom.

Abstract: A composite membrane is provided in which a porous substrate is impregnated with a polymeric composition comprising various combinations of &agr;,&bgr;,&bgr;-trifluorostyrene, substituted &agr;,&bgr;,&bgr;-trifluorostyrene and ethylene-based monomeric units. Where the polymeric composition includes ion-exchange moieties, the resultant composite membranes are useful in electrochemical applications, particularly as membrane electrolytes in electrochemical fuel cells.