Abstract: A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a thin, rigid, dimensionally-stable, non-electrically-conducting support, the support having a plurality of cylindrical, straight-through pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores are unevenly distributed, with some or no pores located along the periphery and more pores located centrally. The pores are completely filled with a solid polymer electrolyte, the solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide. The solid polymer electrolyte may also be deposited over the top and/or bottom surfaces of the support.

Abstract: A multi-gas microsensor assembly for simultaneously detecting carbon dioxide and oxygen in real time. According to one embodiment, the assembly comprises a non-conductive, solid substrate. A plurality of sensing electrodes, a single reference electrode, and a single counter electrode are positioned on one side of the non-conductive, solid substrate. In addition, all of the electrodes are in intimate contact with the same side of a solid-polymer electrolyte anion-exchange membrane, the solid polymer electrolyte membrane having at least one gas diffusion opening aligned with each sensing electrode. The sensor is operated in a three-electrode potentiostatic mode, in which a constant potential is maintained between the sensing and reference electrodes, and the current is measured between the sensing and counter electrodes. Control of the electrodes is achieved with a small bi-potentiostat.

Abstract: A method for the detection of carbon dioxide gas using an electrochemical sensor. The method includes exposing a gas to a sensor, which includes a non-conductive solid substrate and at least one each of a metal oxide sensing electrode, a reference electrode and a counter electrode positioned on the substrate. A solid polymer electrolyte anion-exchange membrane is in intimate contact with the sensing electrode, reference electrode and counter electrode. The method is highly sensitive and selective to carbon dioxide with a very rapid response time.

Abstract: Disclosed are methods and systems for generating hydrogen gas at pressures high enough to fill a hydrogen storage cylinder for stationary and transportation applications. The hydrogen output of an electrochemical hydrogen gas generating device, a hydrogen-producing reactor, or a diluted hydrogen stream is integrated with an electrochemical hydrogen compressor operating in a high-differential-pressure mode. The compressor brings the hydrogen produced by the hydrogen generating device to the high pressure required to fill the storage cylinder.

Abstract: Electrochemical cell comprises, in one embodiment, a proton exchange membrane (PEM), an anode positioned along one face of the PEM, and a cathode positioned along the other face of the PEM. An electrically-conductive, compressible, spring-like, porous pad for defining a fluid cavity is placed in contact with the outer face of the cathode or the outer face of the anode. The porous pad comprises a particulate or mat of one or more doped- or reduced-valve metal oxides, which are bound together with one or more thermoplastic resins.

Abstract: A gas particulate filter well-suited for, but not limited to, removing airborne particulates from air. According to one embodiment, the filter is a composite structure including a porous support and an ionomer coating. The porous support is preferably made of a material designed to endow the filter with good mechanical properties. The pores of the porous support are preferably micron or smaller straight pores. The ionomer coating, which is applied to the porous support but does not completely seal the pores of the porous support, is preferably selected to provide the filter with good filtering properties and regeneration through controlled ionomer hydration/dehydration and corresponding ionomer swelling and contraction.

Abstract: A miniaturized gas sensor including film type electrodes, and a solid ionomer electrolyte, for the detection of toxic gases, i.e., carbon monoxide, and other oxidizable or reducible gases and vapors is described. The all-solid planar sensor cell has two or more film type electrodes arranged on a non-conductive planar surface of a supportive material. The electrodes are discrete and in intimate contact with the same solid polymer ionomer membrane. The sensor cell contains no liquid electrolyte and is operated in a potentiostatic or potentiodynamic mode. The unique feature of the sensor cell is that high sensitivity to a select gas or vapor is achieved by a novel three-phase contact area design for a sensing electrode which is easily accessible to the gas sample via small diffusion openings or holes that penetrate through the solid polymer ionomer membrane layer above the sensing electrode.

Abstract: A solid polymer electrolyte composite membrane and method of manufacturing the same. The composite membrane comprises a porous ceramic support having a top surface and a bottom surface. The porous ceramic support may be formed by laser micromachining a ceramic sheet or may be formed by electrochemically oxidizing a sheet of the base metal. A solid polymer electrolyte fills the pores of the ceramic support and preferably also covers the top and bottom surfaces of the support. Application of the solid polymer electrolyte to the porous support may take place by applying a dispersion to the support followed by a drying off of the solvent, by hot extrusion of the solid polymer electrolyte (or by hot extrusion of a precursor of the solid polymer electrolyte followed by in-situ conversion of the precursor to the solid polymer electrolyte) or by in-situ polymerization of a corresponding monomer of the solid polymer electrolyte.

Abstract: A solid polymer electrolyte composite membrane and method of manufacturing the same. The composite membrane comprises a porous ceramic support having a top surface and a bottom surface. The porous ceramic support may be formed by laser micromachining a ceramic sheet or may be formed by electrochemically oxidizing a sheet of the base metal. A solid polymer electrolyte fills the pores of the ceramic support and preferably also covers the top and bottom surfaces of the support. Application of the solid polymer electrolyte to the porous support may take place by applying a dispersion to the support followed by a drying off of the solvent, by hot extrusion of the solid polymer electrolyte (or by hot extrusion of a precursor of the solid polymer electrolyte followed by in-situ conversion of the precursor to the solid polymer electrolyte) or by in-situ polymerization of a corresponding monomer of the solid polymer electrolyte.

Abstract: A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a thin, rigid, dimensionally-stable, non-electrically-conducting support, the support having a plurality of cylindrical, straight-through pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores are unevenly distributed, with some or no pores located along the periphery and more pores located centrally. The pores are completely filled with a solid polymer electrolyte, the solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide. The solid polymer electrolyte may also be deposited over the top and/or bottom surfaces of the support.

Abstract: A method for the detection of carbon dioxide gas using an electrochemical sensor. The method includes exposing a gas to a sensor, which includes a non-conductive solid substrate and at least one each of a metal oxide sensing electrode, a reference electrode and a counter electrode positioned on the substrate. A solid polymer electrolyte anion-exchange membrane is in intimate contact with the sensing electrode, reference electrode and counter electrode. The method is highly sensitive and selective to carbon dioxide with a very rapid response time.

Abstract: A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 5 microns, are made by laser micromachining and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

Abstract: Electrochemical cell comprises, in one embodiment, a proton exchange membrane (PEM), an anode positioned along one face of the PEM, and a cathode positioned along the other face of the PEM. An electrically-conductive, compressible, spring-like, porous pad for defining a fluid cavity is placed in contact with the outer face of the cathode or the outer face of the anode. The porous pad comprises a particulate or mat of one or more doped- or reduced-valve metal oxides, which are bound together with one or more thermoplastic resins.

Abstract: A multi-gas microsensor assembly for simultaneously detecting carbon dioxide and oxygen in real time. According to one embodiment, the assembly comprises a non-conductive, solid substrate. A plurality of sensing electrodes, a single reference electrode, and a single counter electrode are positioned on one side of the non-conductive, solid substrate. In addition, all of the electrodes are in intimate contact with the same side of a solid-polymer electrolyte anion-exchange membrane, the solid polymer electrolyte membrane having at least one gas diffusion opening aligned with each sensing electrode. The sensor is operated in a three-electrode potentiostatic mode, in which a constant potential is maintained between the sensing and reference electrodes, and the current is measured between the sensing and counter electrodes. Control of the electrodes is achieved with a small bi-potentiostat.

Abstract: A membrane electrode assembly including an ionically conductive member, an electrode, and an electrically conductive member including an active layer, wherein the electrode is a smooth, continuous layer that completely covers and supports the ionically conductive member. The electrode and active layer further include a first and second catalyst content, respectively; and 50% of the total catalyst content is present in the electrode and 50% of the total catalyst content is present in the active layer.

Abstract: An electrochemical sensor is provided for the detection of carbon dioxide gas. The sensor includes a non-conductive solid substrate and at least one each of a metal oxide sensing electrode, a reference electrode and a counter electrode positioned on the substrate. A solid polymer electrolyte anion-exchange membrane is in intimate contact with the sensing electrode, reference electrode and counter electrode. The sensor is highly sensitive and selective to carbon dioxide and has very rapid response time.

Abstract: A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

Abstract: Electrolysis cell comprises, in one embodiment, a proton exchange membrane (PEM), an anode positioned along one face of the PEM, and a cathode positioned along the other face of the PEM. An electrically-conductive, compressible, spring-like, porous pad for defining a fluid cavity is placed in contact with the outer face of the cathode. The porous pad comprises a mat of carbon fibers bound together with one or more, preferably thermoplastic, resins, the mat having a density of about 0.2-1.5 g/cm3. Cell frames are placed in peripheral contact with the metal screen and the compression pad for peripherally containing fluids present therewithin. Electrically-conductive separators are placed in contact with the metal screen and the compression pad for axially containing fluids present therewithin. A plurality of the cells may be arranged in series in a bipolar configuration without requiring a separate compression pad between cells (for gas pressure differentials up to about 400 psi or greater).

Abstract: A gas diffusion electrode and method of making the same. According to one embodiment, the electrode comprises a support layer, a first cushioning layer positioned on top of the support layer, a second cushioning layer positioned on top of the first cushioning layer, and a catalyst layer positioned on top of the second cushioning layer. The support layer is a mechanically stable, electrically-conductive, gas porous substrate, such as carbon fiber paper. The first cushioning layer, which is also gas porous, comprises a non-woven mat of electrically-conductive, chemically-inert fibers, preferably carbon nanofibers, bound together with a polymeric binder, such as polytetrafluoroethylene. The second cushioning layer is similar to the first cushioning layer, except that carbon black or a similar electrically-conductive, chemically-inert particulate material is included in addition to or instead of the fibrous material for the purpose of fine-tuning pore size.

Abstract: Cell frame for high-pressure water electrolyzer and method of manufacturing the same. According to one embodiment, radial openings in a water electrolyzer frame are provided by laminating half-frames, one or both of which contains grooves that may be formed by molding, machining or die-cutting. Another to another embodiment, radial openings are provided by laminating three or more thin frame portions, the center piece of which may include transverse slots that may be made by molding, machining or die-cutting. According to yet another embodiment, two or more frame portions are provided, at least one of which includes a recess for receiving a porous structure. The frames of the present invention can be additionally laminated to the membrane and electrode assembly, as well as the bipolar separator plate in the perimeter or seal area, comprised of the same or similar material as the frame, to form unitized electrolyzer stack subassemblies or full assemblies.