摘要:
A unitized electrode assembly (9) for use in the fuel cell comprises a first GDL (23), a PEM (28), and a second GDL (12), with electrode catalyst (27, 30) disposed between said PEM and each of said GDLs, said layers (23, 27, 30, 12) being impregnated with a thermoplastic polymer a sufficient distance from each edge of the UEA so as to form a fluid seal (13). The UEA is formed by a process which comprises making a sandwich of some or all of said layers (23, 27, 28, 30 and 33), with thermoplastic polymer film (22, 25, 32, 35) extending inwardly from the edges of said sandwich a sufficient distance to form the seal, said thermoplastic polymer film being disposed between each electrode and the adjacent GDL and/or between each GDL and release film (21, 36) on the top and bottom of the sandwich. The sandwich, compressed by force between a holding fixture (19) and an anvil (40), is heated by ultrasonic vibration so as to cause said thermoplastic polymer to melt and impregnate the layers (23, 27, 30, 12) of the UEA with the film (22 and/or 25; 32 and/or 35).
摘要:
The present invention generally relates to nanostructures and compositions comprising nanostructures, methods of making and using the nanostructures, and related systems. In some embodiments, a nanostructure comprises a first region and a second region, wherein a first photocatalytic reaction (e.g., an oxidation reaction) can be carried out at the first region and a second photocatalytic reaction (e.g., a reduction reaction) can be carried out at the second region. In some cases, the first photocatalytic reaction is the formation of oxygen gas from water and the second photocatalytic reaction is the formation of hydrogen gas from water. In some embodiments, a nanostructure comprises at least one semiconductor material, and, in some cases, at least one catalytic material and/or at least one photosensitizing agent.
摘要:
A unitized electrode assembly (9) for use in the fuel cell comprises a first GDL (23), a PEM (28), and a second GDL (12), with electrode catalyst (27, 30) disposed between said PEM and each of said GDLs, said layers (23, 27, 30, 12) being impregnated with a thermoplastic polymer a sufficient distance from each edge of the UEA so as to form a fluid seal (13). The UEA is formed by a process which comprises making a sandwich of some or all of said layers (23, 27, 28, 30 and 33), with thermoplastic polymer film (22, 25, 32, 35) extending inwardly from the edges of said sandwich a sufficient distance to form the seal, said thermoplastic polymer film being disposed between each electrode and the adjacent GDL and/or between each GDL and release film (21, 36) on the top and bottom of the sandwich. The sandwich, compressed by force between a holding fixture (19) and an anvil (40), is heated by ultrasonic vibration so as to cause said thermoplastic polymer to melt and impregnate the layers (23, 27, 30, 12) of the UEA with the film (22 and/or 25; 32 and/or 35).
摘要:
To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) intersecting polygons, obtuse angles including triangles, trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120).
摘要:
The present invention generally relates to nanostructures and compositions comprising nanostructures, methods of making and using the nanostructures, and related systems. In some embodiments, a nanostructure comprises a first region and a second region, wherein a first photocatalytic reaction (e.g., an oxidation reaction) can be carried out at the first region and a second photocatalytic reaction (e.g., a reduction reaction) can be carried out at the second region. In some cases, the first photocatalytic reaction is the formation of oxygen gas from water and the second photocatalytic reaction is the formation of hydrogen gas from water. In some embodiments, a nanostructure comprises at least one semiconductor material, and, in some cases, at least one catalytic material and/or at least one photosensitizing agent.
摘要:
To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) cross sections having intersecting polygons or other shapes, obtuse angles including triangles and trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120), or (e) diverging channels (152).
摘要:
To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) intersecting polygons, obtuse angles including triangles, trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120).
摘要:
A membrane electrode assembly includes an anode; a cathode; a membrane disposed between the anode and the cathode; and an extended catalyzed layer between the membrane and at least one electrode of the anode and the cathode. The extended catalyzed layer includes catalyst particles embedded in membrane material and preferably includes a first plurality of particles which are electrically connected to the at least one electrode. The extended catalyzed layer may further preferably have a second plurality of particles which are electrically disconnected from the at least one electrode.
摘要:
A decontamination procedure for a fuel cell power plant (10) includes operating the plant to produce electrical power for an operating period, and then terminating operation of the plant (10) for a decontamination period, and then, whenever optimal electrical production of a plant fuel cell (12) is reduced by at least 5% by contaminants adsorbed by fuel cell electrodes (24, 42), decontaminating the fuel cell (12) of the plant (10) during the decontamination period by oxidizing contaminants adsorbed by electrodes (24, 42) of the fuel cell. Oxidizing the contaminants may be accomplished by various steps including exposing the electrodes (24, 42) to flowing oxygen; to heated flowing oxygen; to a sequence of start-stop cycles; and, to varying controlled potentials.
摘要:
A membrane electrode assembly includes an anode including a hydrogen oxidation catalyst; a cathode; a membrane disposed between the anode and the cathode; and a peroxide decomposition catalyst positioned in at least one position selected from the group consisting of the anode, the cathode, a layer between the anode and the membrane and a layer between the cathode and the membrane wherein the peroxide decomposition catalyst has selectivity when exposed to hydrogen peroxide toward reactions which form benign products from the hydrogen peroxide. The peroxide decomposition catalyst can also be positioned within the membrane. Also disclosed is a power-generating fuel cell system including such a membrane electrode assembly, and a process for operating such a fuel cell system.