Other

Physical Sciences, Inc.

Psi Technology Co.

Everett B Anderson

E Jennings Taylor

Alan S Woodman

Earl J Taylor

N R Reddy

Mark E Fraser

In the disclosed electrochemical cell for the production of an alkaline solution of peroxide, especially on-site production, the electrolyte is divided into an aqueous alkaline catholyte and an aqueous alkaline anolyte, and the cathode is a gas-diffusion electrode. The active material of the electrolyte side of the gas-diffusion cathode comprises a particulate catalyst support material having a surface area of about 50 to about 2000 m.sup.2 /g, and, deposited on the particles of this support material, 0.1 to 50 weight-%, based on the weight of the active layer, of gold or gold alloy particles having an average size &gt;40 but less than about 200 .ANG.. These gold or gold alloy particles are substantially selectively catalytic for the reduction of oxygen to peroxide (e.g. HOO.sup..crclbar.). The electrolyte flow patterns are designed to avoid loss of peroxide resulting from oxidation at the anode. In the operation of the cell, a product with a hydroxyl:perhydroxyl ratio lees than 2:1 can be obtained.

Electrode for peroxide generator and method for preparing it

In the disclosed electrochemical cell for the production of an alkaline solution of peroxide, especially on-site production, the electrolyte is divided into an aqueous alkaline catholyte and an aqueous alkaline anolyte, and the cathode is a gas-diffusion electrode. The active material of the electrolyte side of the gas-diffusion cathode comprises a particulate catalyst support material having a surface area of about 50 to about 2000 m.sup.2 /g, and, deposited on the particles of this support material, 0.1 to 50 weight-%, based on the weight of the active layer, of gold or gold alloy particles having an average size &gt;40 but less than about 200.ANG.. These gold or gold alloy particles are substantially selectively catalytic for the reduction of oxygen to peroxide (e.g. HOO.sup..crclbar.). The electrolyte flow patterns are designed to avoid loss of peroxide resulting from oxidation at the anode. In the operation of the cell, a product with a hydroxyl:perhydroxyl ratio less than 2:1 can be obtained.

Process for making peroxide

In the disclosed electrochemical cell for the production of an alkaline solution of peroxide, especially on-site production, the electrolyte is divided into an aqueous alkaline catholyte and an aqueous alkaline anolyte, and the cathode is a gas-diffusion electrode. The active material of the electrolyte side of the gas-diffusion cathode comprises a particulate catalyst support material having a surface area of about 50 to about 2000 m.sup.2 /g, and, deposited on the particles of this support material, 0.1 to 50 weight-%, based on the weight of the active layer, of gold or gold alloy poly-crystal particles having an average size .gtoreq.5 but less than about 20 nanometers. These poly-crystal gold or gold alloy particles have a structure consisting essentially of combined individual monocrystals and are substantially selectively catalytic for the reduction of oxygen to peroxide ion or hydrogen peroxide (e.g. HOO.sup..theta.). The electrolyte flow patterns are designed to avoid loss of peroxide resulting from oxidation at the anode. In the operation of the cell, a product with a hydroxyl:perhydroxyl ratio less than 2:1 can be obtained.

Electrochemical peroxide generator

The gas-sensing electrodes prepared according to this invention are specifically designed for cells which operate in a current-limited mode, i.e. at current densities well below 20 mA/cm.sup.2. Such cells are particularly useful to measure or detect a gaseous component of a gaseous environment or stream, provided the gaseous component can be electrochemically oxidized or reduced. In an alkaline, metal-oxygen cell for example, an electrode of this invention can be used as an oxygen cathode. The electrode is prepared by:

Electrode for current-limited cell, cell including the electrode method

Gas-diffusion electrodes (GDE's) suitable for use with a solid polymer electrolyte (s.p.e.), particularly in s.p.e. fuel cells, which GDE's provide unusually highly efficient use of noble or precious electrocatalytic metals, are obtained by starting with a GDE which is essentially fully fabricated except for electrocatalytic metal treatment and s.p.e. treatment, e.g. a carbon GDE having a gas-permeable hydrophobic face and a particulate carbon-containing catalytic face. This untreated GDE is treated by

High utilization supported catalytic metal-containing gas-diffusion

A towed levee forming apparatus and method of using for forming a dike or levee which is particularly suited for use with agriculture operations. The apparatus includes a plurality of laterally spaced digger means for forming corresponding ditches in the ground surface and having a helical auger means transporting the earth removed from the ditches to a predetermined location on the apparatus. The removed earth is then deposited at the predetermined location on the earth surface and worked to form a levee of desired cross-section. The levee formation is preferably accomplished in a single pass of the apparatus.

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Reading, MA, United States of America

Everett B Anderson