General Electric Company

E.i. Dupont De Nemours and Company

United Technologies Corporation

Anthony B La Conti

Thomas G Coker

Russell M Dempsey

John A Kosek

Mary E Nolan

Shoibal Banerjee

Anthony R Fragala

Cecelia C Cropley

John F Enos

Ivan F Danzig

Joseph M Amore

Cation exchange membranes incorporating a thin layer of polymer having having a high ratio of backbone carbon atoms to cation exchange groups provide improved performance in direct methanol fuel cells.

Membrane and electrode assembly employing exclusion membrane for direct

A process for producing sulfuric acid and caustic soda by the electrolysis of an alkali metal sulfate in a membrane cell having a hydrogen depolarized anode. Hydrogen gas in the anode chamber is oxidized to produce hydrogen cations which combine with the sulfate anions from the aqueous alkali metal sulfate solution to produce sulfuric acid. Alkali metal ions are transported across the membrane to the cathode to produce caustic and gaseous hydrogen. By oxidizing hydrogen at the anode, the cell voltage for the electrolysis of the alkali metal sulfate is substantially reduced.

Electrolysis of alkali metal salts with hydrogen depolarized anodes

A gas generating apparatus and method is described which utilizes a novel catalytic oxygen evolving electrode for such electrochemical systems as electrolysis cells and oxygen concentration cells. The electrochemical cells include a catalytic cathode and an improved catalytic anode positioned on opposite sides of, and in electrical contact with, a cation exchange membrane. A source of direct current potential between the cathode and the anode and means for removing gas from at least one of the electrodes are provided. The improved catalytic anode is a ternary platinum group reduced metal oxide alone or in combination with platinum group metals and/or platinum group metal oxides or mixtures of the foregoing having at least one valve metal component such as titanium, hafnium, zirconium, niobium, tantalum, and tungsten.

Device for evolution of oxygen with ternary electrocatalysts containing

A gas detecting and measuring device and method highly selective for the detection of certain gases is described. The gas detector is capable of detecting and measuring a gas which can be electrochemically oxidized or electrochemically reduced at a voltage of between about 0.6 and 1.5 volts relative to a standard hydrogen electrode. The gas detecting and measuring device and process are highly selective for the oxides of nitrogen (NO.sub.x) and chlorine. The gas detecting device utilizes a hydrated, solid polymer electrolyte ion transporting membrane in electrical contact with an improved catalytic graphite sensing electrode. For detecting an oxidizable gas such as nitric oxide (NO), an improved graphite anode in contact with the solid polymer electrolyte is used with a cathode and a reference electrode as an electrochemical cell, and for detecting a reducible gas such as chlorine (Cl.sub.2) or nitrogen dioxide (NO.sub.2), an improved graphite cathode is used with an anode and a reference electrode as an electrochemical cell. Under an applied voltage, oxidizable gas is oxidized at the graphite anode and is detected or measured by a suitable circuit as a result of the current generated by the oxidation reaction, or reducible gas is reduced at the graphite cathode and is detected or measured by a suitable circuit as a result of the current generated by the reduction reaction.

Gas sensing and measuring device and process using catalytic graphite

A halogen such as chlorine is produced by the electrolysis of an aqueous solution of a hydrogen halide such as hydrochloric acid in an electrolysis cell having anolyte and catholyte chambers separated by a solid polymer electrolyte in the form of a stable, selectively permeable, hydrated ion exchange membrane. Catalytic electrodes in the form of fluorocarbon bonded, thermally stabilized, reduced oxides of platinum group metals are bonded to at least one surface of the membrane and an aqueous hydrochloric acid solution is brought in contact with the bonded anode to generate chlorine at the anode and hydrogen at the cathode.

Generation of halogens by electrolysis of hydrogen halides in a cell

A halogen, such as chlorine, is generated in an electrolysis cell in which at least one of the cell electrodes is bonded to the surface of a solid but porous membrane which separates the cell into anode and cathode chambers. A pressurized aqueous metal halide such as brine is electrolyzed at the anode to produce chlorine. Brine anolyte and sodium ions are hydraulically transported across the porous membrane to produce caustic (NaOH) at the cathode. By bonding at least one gas permeable, porous electrode to the hydraulically permeable membrane, the cell voltage for electrolysis of brine is considerably lower than that required for asbestos diaphragm cells, while achieving high cathodic current efficiencies by minimizing back migration of caustic to the anode.

Production of halogens by electrolysis of alkali metal halides in a cell

A compact electrochemical gas sensing cell is described for detecting gases which are either immediately dangerous to health such as carbon monoxide, NO.sub.2, etc., or represent a social or public welfare risk. The latter area, for example, may require determining alcohol breath content of a driver of a motor vehicle. The cell uses a hydrated, solid polymer electrolyte which has sensing and reference electrodes positioned on one side of the solid polymer electrolyte membrane and a counter electrode positioned on the other side. One side of the hydrated SPE membrane is flooded with distilled water so that incoming gases are brought to essentially 100% relative humidity by rapid vapor phase water transport across the membrane, thereby eliminating the need for external humidification in the form of bubblers and the like. An ionically conductive hydrated SPE bridge is formed on one side of the membrane and is located spatially to provide a low resistance path between the reference and sensing electrodes.

Self-humidifying potentiostated, three-electrode hydrated solid polymer

A gas generation apparatus which is useful for the concentration of oxygen or for the generation of oxygen and hydrogen by electrolysis has a catalytic cathode, an improved catalytic anode with a catalyst selected from platinum-iridium alloys containing 5 to 50 per cent iridium, a cation-exchange membrane positioned between and in electrical contact with the cathode and anode, means for providing a direct current potential between the cathode and the anode, and outlet means for removing gas from at least one of the electrodes. Methods are described for the concentration of oxygen and for generation of oxygen and hydrogen by electrolysis.

Growing community of inventors

Lynnfield, MA, United States of America

Anthony B La Conti