Physical Sciences, Inc.

Gary A Moniz

Joseph J Helble

Theodore F Morse

Earl J Taylor

Joseph Renard Morency

Melanie J Gouveia

David O Ham

An apparatus provides high temperature and short residence time conditions for the production of nanoscale ceramic powders. The apparatus includes a confinement structure having a multiple inclined surfaces for confining flame located between the surfaces so as to define a flame zone. A burner system employs one or more burners to provide flame to the flame zone. Each burner is located in the flame zone in close proximity to at least one of the inclined surfaces. A delivery system disposed adjacent the flame zone delivers an aerosol, comprising an organic or carbonaceous carrier material and a ceramic precursor, to the flame zone to expose the aerosol to a temperature sufficient to induce combustion of the carrier material and vaporization and nucleation, or diffusion and oxidation, of the ceramic precursor to form pure, crystalline, narrow size distribution, nanophase ceramic particles.

Apparatus for producing nanoscale ceramic powders

Submicron sized ceramic particles are produced by combining a ceramic precursor with an organic or carbonaceous carrier material, and exposing droplets of the mixture to a temperature sufficient to cause combustion of the organic material and subsequent vaporization and nucleation, or diffusion and oxidation, of the ceramic precursor to form pure, crystalline, uniform nanophase ceramic particles.

Process for producing nanoscale ceramic powders

The disclosed electrocatalyst material is useful in electrodes, especially in cathodes for the reduction of oxygen or peroxide to water or hydroxide. The electrocatalyst typically comprises 0.1 to 20 weight-%, based on the weight of the material, of a supported particulate elemental gold wherein the particles are apparently crystalline in nature, apparently with exposed (100) faces, but smaller in size than 5 nanometers (&lt;.ANG.). These tiny monocrystals of gold are supported on carbon black or particulate conductive ceramic-like compounds having a B.E.T. surface area of at least 50 m.sup.2 /g. The supported gold monocrystals appear to be selective for the reductions described above, and performance in air- or O.sub.2 -cathodes is outstanding, e.g. &gt;0.7 volts vs. RHE at 200 mA/cm.sup.2, generally indicating a substantial proportion of four-electron change reactions when oxygen is being reduced. The electrodes (which are also useful as anodes in acid electrolytes) are made by impregnating the support material with a reducible gold compound dissolved in a polar solvent, gently evaporating the solvent, and chemically reducing the gold compound in situ at a moderate temperature with a flowing reducing gas (e.g. H.sub.2) then applying the resulting supported gold to a porous backing material. Typical gold content levels at the electrode surface are &lt;2 mg/cm.sup.2. Cathodes of this invention are useful in various types of air or oxygen-depolarized cells, alkaline fuel cells, metal/air cells, metal/H.sub.2 O.sub.2 cells, oxygen sensors, electrochemical caustic concentrators, etc.

Electrochemical cell having electrode comprising gold containing

A method for removing NO.sub.x, particularly nitrogen oxide, emissions from the exhaust products of combustion processes is disclosed. An alkyl amine is added to the stream of exhaust products at relatively low temperatures in the range of 350.degree.-650.degree. C. The alkyl amine does not require a catalyst to react with the nitrogen oxides at these temperatures. Monomethyl amine (CH.sub.3 NH.sub.2) is particularly useful.

Process for removing NO.sub.x emissions from combustion effluents

The disclosed electrocatalyst material is useful in electrodes, especially in cathodes for the reduction of oxygen or peroxide to water or hydroxide. The electrocatalyst typically comprises 0.1 to 20 weight-%, based on the weight of the material, of a supported particulate elemental gold wherein the particles are apparently crystalline in nature, apparently with exposed (100) faces, but smaller in size than 5 nanometers (&lt;50.ANG.). These tiny monocrystals of gold are supported on carbon back or particulate conductive ceramic-like compounds having a B.E.T. surface area of at least 50 m.sup.2 /g. The supported gold monocrystals appear to be selective for the reductions described above, and performance in air- or O.sub.2 -cathodes is outstanding, e.g. &gt;0.7 volt vs. RHE at 200 mA/cm.sup.2, generally indicating a substantial proportion of four-electron change reactions when oxygen is being reduced. The electrodes (which are also useful as anodes in acid electrolytes) are made by impregnating the support material with a reducible gold compound dissolved in a polar solvent, gently evaporating the solvent, and chemically reducing the gold compound in situ at a moderate temperature with a flowing reducing gas (e.g. H.sub.2), then applying the resulting supported gold to a porous backing material. Typical gold content levels at the electrode surface are &lt;2 mg/cm.sup.2. Cathodes of this invention are useful in various types of air or oxygen-depolarized cells, alkaline fuel cells, metal/air c

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Windham, NH, United States of America

Gary A Moniz