Abstract: 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 ?m to 30 ?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.

Abstract: 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 ?m to 30 ?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.

Abstract: A gas diffusion electrode comprises at least one gas diffusion media, at least one supported catalyst layer disposed on top of the gas diffusion media, the supported catalyst layer comprising at least one supported catalyst, and an unsupported catalyst layer disposed on top of the supported catalyst layer, the unsupported catalyst layer having a higher total catalyst loading than the supported catalyst layer.

Abstract: A method of producing a finely divided ruthenium-platinum alloy catalyst comprising: (i) forming a mixture of platinum ?-diketone and ruthenium ?-diketone on a carbon support, (ii) both, platinum ?-diketone and ruthenium ?-diketone having a decomposition temperature within 20° C. of each other, (iii) decomposing said platinum ?-diketone and ruthenium ?-diketone on a carbon support at a temperature of at least 260° C. in the absence of a reducing agent (iv) followed by a reduction effected with a hydrogen containing gas mixture and a method from oxidizing methanol.

Abstract: 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.

Abstract: 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.

Abstract: A method of production of highly alloyed supported or unsupported platinum-ruthenium catalysts by simultaneous precipitation of the corresponding hydrous oxides or hydroxides and subsequent reduction wherein the simultaneous precipitation of platinum and ruthenium hydrous oxides is made possible by mixing two separate precursor solutions of the two metals, one in acidic and the other in basic environment, until reaching a near-neutral pH at which both hydrous oxide species are insoluble.

Abstract: The instant invention relates to a platinum alloy supported electrocatalyst for gas diffusion electrode and/or in catalyst-coated membrane.

Abstract: A carbon-supported platinum alloy catalyst obtained by simultaneous chemical reduction of in situ-formed platinum dioxide and of at least one transition metal hydrous oxide on a carbon support.

Abstract: A method of production of highly alloyed supported or unsupported platinum-ruthenium catalysts by simultaneous precipitation of the corresponding hydrous oxides or hydroxides and subsequent reduction wherein the simultaneous precipitation of platinum and ruthenium hydrous oxides is made possible by mixing two separate precursor solutions of the two metals, one in acidic and the other in basic environment, until reaching a near-neutral pH at which both hydrous oxide species are insoluble.

Abstract: A catalytic powder comprising a plurality of support metal particles with a porous coating (12) surrounding the metal particles (11), the porous coating comprising either an electrocatalytic metal or an electrocatalytic metal continuous phase in admixture with a particulate material (14). 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A binary platinum-ruthenium alloy suitable as the active component of a direct methanol fuel cell anode and use thereof in a fuel cell and the method of forming a catlyst therefrom.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.