The Dow Chemical Company

Basf Fuel Cell Gmbh

Basf Se Corporation

De Nora Elettrodi S.p.a

Dow Global Technolgoies LLC

Industrie De Nora S.p.a.

Basf Schweiz Ag

Yu-Min Tsou

Emory Sayre De Castro

Glenn A Eisman

James W McMichael

Gian Nicola Martelli

Robert D Door

Lixin Cao

Hua Deng

Robert J Allen

Roy L Hicks

Richard N Beaver, Deceased

Harry S Burney, Jr

Zhenyu Liu

Thomas J Pisklak

Richard N Beaaver, Deceased

Edmond L Manor

Michael Schneider

Jeffrey G Morse

Maria Josefina Cayetano

The present invention relates to improved membrane electrode assemblies, having two electrochemically active electrodes separated by a polymer electrolyte membrane. The membrane electrode assemblies according to the instant invention contains at least one phosphoric acid-containing polymer electrolyte membrane and two gas diffusion electrodes one of each located at both sides of said membrane, each of the gas diffusion electrodes having at least one catalyst layer facing towards the membrane. At least one of the gas diffusion electrodes contains a gas diffusion medium comprising an electrically conductive macroporous layer in which the pores have a mean pore diameter in the range from 10 &#x3bc;m to 30 &#x3bc;m and at least one micro porous layer arranged between said gas diffusion medium and said catalyst layer facing towards the membrane having a defined pore void volume and pore hydrophobicity measured by the Cobb Titration.

Membrane electrode assemblies

A method of producing a finely divided ruthenium-platinum alloy catalyst comprising:

Metal alloy for electrochemical oxidation reactions and method of production thereof

An improved structure for gas diffusion electrodes and gas diffusion layers whereby fine gradients of porosity and hydrophobicity promote efficient gas transport, water removal and overall enhanced performance of Membrane Electrode Assemblies constructed with these components.

Structures for gas diffusion materials and methods for their fabrication

A carbon-supported platinum catalyst obtained by chemical reduction of in situ-formed platinum dioxide on a carbon support and a method of production thereof.

Platinum catalysts from in situ formed platinum dioxide

A catalytic powder comprising a plurality of support metal particles with a porous coating () surrounding the metal particles (), the porous coating comprising either an electrocatalytic metal or an electrocatalytic metal continuous phase in admixture with a particulate material (). An electrode made with the catalytic powder and a method to make the electrode is also disclosed. The present invention is advantageous because the porous coating mixture is first applied to a powder rather than being applied directly to a metal substrate, thereby creating a large internal surface area on the electrode and accordingly, lower overpotential requirements.

Catalytic powder and electrode made therewith

A rhodium sulfide electrocatalyst formed by heating an aqueous solution of rhodium salt until a steady state distribution of isomers is obtained and then sparging hydrogen sulfide into the solution to form the rhodium sulfide and a membrane electrode assembly with the said electrode and a process for electrolyzing hydrochloric acid.

Rhodium electrocatalyst and method of preparation

Durable electrolytic cell electrodes having low hydrogen overpotential and performance stability. A highly porous electrocatalytic primary phase and an outer, secondary phase reinforcement coating are provided on an electrically conducting transition metal substrate to make the electrodes. Durability is achieved by the application of the outer secondary phase to protect the primary phase electrocatalytically active coating. A process is also disclosed for catalizing a substrate surface to promote electroless deposition of a metal.

Durable electrode coatings

Stable catalytic coating solutions are prepared using soluble compounds of at least two platinum group metals or at least one platinum group metal and at least one soluble compound of a valve metal. Valve metal anode bases coated with mixed oxide catalytic coating layers of a valve metal oxide and a platinum group metal oxide can be prepared with longer useful life by incorporation of a second platinum group metal. A mixed oxide coating of ruthenium, iridium, and titanium oxides is preferred for the coating layers in order to provide longer useful anode life.

Sable coating solutions for coating valve metal anodes

A membrane-electrode structure for use in an electrochemical cell comprising an ion exchange membrane with a cathode layer and several intermediate layers between the cathode and the membrane. The intermediate layers comprises at least two layers or zones of inorganic solid particles and an organic polymer binder. The intermediate layer or zone adjacent to the membrane comprises more than 50% by weight of inorganic particles and the other layers or zones have 50% by weight or less of inorganic particles.

Membrane-electrode structure for electrochemical cells

A supported catalyst useful in the preparation of an electrode for an electrochemical cell which comprises the residue remaining after heating at about 500.degree. to about 800.degree. C. a transition metal and a polymer such as polyvinylpyridine all adsorbed on a support material. Useful electrodes are prepared by combining the supported catalyst with a current collector.

Electrochemical cell electrode

A membrane-electrode structure for use in an electrochemical cell comprising an ion exchange membrane with a cathode layer and an intermediate layer between the cathode and the membrane. The intermediate layer comprises about 5 to 80% by weight of inorganic solid particles and about 95 to 20% by weight of an ionic conductive polymeric binder.

A supported catalyst useful in the preparation of an electrode for an electrochemical cell which comprises the residue remaining after heating at about 500.degree. to about 700.degree. C. a transition metal and a polymer such as polyvinylpyridine all adsorbed on a support material. Useful electrodes are prepared by combining the supported catalyst with a current collector.

Methods are disclosed to control reverse current flow in stacks of membrane electrolytic cells during off-line periods. One method includes the introduction of a stripping gas flow to the anolyte solution of the cells during an interruption of normal positive current flow. In another embodiment, reverse current flow is controlled by introducing at least one soluble reducing agent to the anolyte solution during an interruption of normal positive current flow. Also disclosed is a porous sparging apparatus useful in introducing a stripping gas flow to a stack of membrane electrolytic cells.

Growing community of inventors

Lake Jackson, TX, United States of America

Yu-Min Tsou