Abstract: The invention relates to a membrane-electrode unit comprising a) two electrochemically active electrodes divided by a polymer electrolytic membrane, wherein the surfaces of said polymer electrolytic membrane are in contact with the electrodes in such a way that the first electrode partially or entirely covers the front side of the polymer electrolytic membrane and the second electrode partially or entirely covers the rear side thereof, b) a sealing material is applied to the front and rear sides of the polymer electrolytic membrane, wherein the polymer electrolytic membrane is provided with one or several recesses and the sealing material applied to the front side of the polymer electrolytic membrane is in contact with the sealing material applied to the rear side thereof. A method for producing said membrane-electrode unit and fuel cells provided therewith are also disclosed.

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: The present invention relates to a proton-conducting polymer membrane comprising polyazoles which is obtainable by a process comprising the steps A) preparation of a mixture comprising polyphosphoric acid, at least one polyazole and/or one or more compounds suitable for forming polyazoles under the action of heat in step B), B) heating of the mixture obtainable according to step A) to temperatures up to 400° C. under inert gas, C) application of a layer to a support using the mixture from step A) and/or B), D) treatment of the membrane formed in step C) until it is self-supporting, wherein the treatment of the membrane is carried out using a hydrolysis liquid comprising oxo acids of phosphorus and/or oxo acids of sulfur.

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: The present invention concerns a proton-conducting electrolyte membrane obtainable by a method comprising the following steps: A) expanding a polymer film with a liquid that contains a vinyl-containing phosphonic acid, and B) polymerisation of the vinyl-containing phosphonic acid present in the liquid introduced in step A). An inventive membrane, thanks to its exceptional chemical and thermal properties, is very versatile in its use and is particularly suitable as a polymer-electrolyte-membrane (PEM) in so-called PEM fuel cells.

Abstract: The present invention relates to an asymmetric polymer film, in particular based on polazoles, a method for the production of the same and its use. The polyazole-based asymmetric polymer film according to the invention has a smooth and a rough side and enables, on account of its asymmetric structure, rapid and homogeneous doping with acids to form a proton-conducting membrane. The polyazole-based asymmetric polymer film according to the invention can be used in diverse ways on account of its excellent chemical, thermal and mechanical properties and is particularly suitable for the production of polymer electrolyte membranes (PEM) for so-called PEM fuel cells.

Abstract: The present invention relates to a novel polymer film and also polymer fibers and polymers based on polyazoles, which can, owing to its excellent chemical and thermal properties, be used for a variety of purposes and is particularly useful as film or membrane for gas purification and filtration.

Abstract: The present invention relates to a proton-conducting polymer membrane comprising polymers containing phosphonic acid groups which is obtainable by a process comprising the steps A) mixing of vinyl-containing phosphonic acid with one or more aromatic tetramino compounds with one or more aromatic carboxylic acids, esters thereof, acid halides thereof or anhydrides thereof which contain at least two acid groups per carboxylic acid monomer, and/or mixing of vinyl-containing phosphonic acid with one or more aromatic and/or heteroaromatic diamino carboxylic acids, esters thereof, acid halides thereof or anhydrides thereof, B) heating of the mixture obtainable according to step A) under inert gas at temperatures of up to 350° C. to form polyazole polymers, C) application of a layer using the mixture from step A) and/or B) to a support, D) polymerization of the vinyl-containing phosphonic acid present in the sheet-like structure obtainable according to step C).

Abstract: A gas diffusion electrode comprising an electrically conductive web, a non-catalyzed gas diffusion layer comprising at least one electroconductive filler and at least one binder, and a noble metal coating obtained by subjecting an electrically conductive web to a first ion beam having an energy not higher than 500 eV, then to a second beam having an energy of at least 500 eV, containing the ions of at least one noble metal.

Abstract: The present invention relates to a proton-conducting polymer membrane which comprises polyazole blends and is obtainable by a process comprising the steps A) preparation of a mixture comprising polyphosphoric acid, at least one polyazole (polymer A) and/or one or more compounds which are suitable for forming polyazoles under the action of heat according to step B), B) heating of the mixture obtainable according to step A) under inert gas to temperatures of up to 400° C., C) application of a layer using the mixture from step A) and/or B) to a support, D) treatment of the membrane formed in step C) until it is self-supporting, wherein at least one further polymer (polymer B) which is not a polyazole is added to the composition obtainable according to step A) and/or step B) and the weight ratio of polyazole to polymer B is in the range from 0.1 to 50.

Abstract: The invention relates to a novel proton-conducting polymer membrane based on polyazols. Said polymer membrane can be used in a variety of ways due to its outstanding chemical and thermal properties and is especially suitable as a polymer electrolyte membrane (PEM) for producing membrane electrode units for so-called PEM fuel cells.

Abstract: A proton-conducting polymer membrane comprising polyazoles containing sulfonic acid groups is obtainable by a process comprising: A) mixing one or more aromatic or heteroaromatic tetraamino compounds with one or more aromatic or heteroaromatic carboxylic acids or derivatives thereof which contain at least two acid groups per carboxylic acid monomer, with at least part of the tetraamino compounds or the carboxylic acids comprising at least one sulfonic acid group, or mixing of one or more aromatic or heteroaromatic diaminocarboxylic acids, of which at least part comprises sulfonic acid groups, in polyphosphoric acid to form a solution or dispersion; B) optionally heating the solution or dispersion obtained by step A) under inert gas to temperatures of up to 325° C. to form polyazole polymers; C) applying a layer using the mixture from step A) or B) to a support, thus forming a membrane, and D) partially hydrolyzing the polyphosphoric acid moieties of the membrane from step C) until it is self-supporting.

Abstract: A proton-conducting polymer membrane comprising polyazoles containing phosphonic acid groups is obtainable by a process comprising: A) mixing one or more aromatic or heteroaromatic tetraamino compounds with one or more aromatic or heteroaromatic carboxylic acids or derivatives thereof which contain at least two acid groups per carboxylic acid monomer, with at least part of the tetraamino compounds or the carboxylic acids comprising at least one phosphonic acid group, or mixing of one or more aromatic or heteroaromatic diaminocarboxylic acids, of which at least part comprises phosphonic acid groups, in polyphosphoric acid to form a solution or dispersion; B) optionally heating the solution or dispersion obtained by step A) under inert gas to temperatures of up to 350° C.

Abstract: The present invention relates to a proton-conducting polymer membrane comprising polymers containing phosphonic acid groups which is obtainable by a process comprising the steps A) mixing of vinyl-containing phosphonic acid with one or more aromatic tetraamino compounds with one or more aromatic carboxylic acids, esters thereof, acid halides thereof or anhydrides thereof which contain at least two acid groups per carboxylic acid monomer, and/or ?mixing of vinyl-containing phosphonic acid with one or more aromatic and/or heteroaromatic diamino carboxylic acids, esters thereof, acid halides thereof or anhydrides thereof, B) heating of the mixture obtainable according to step A) under inert gas at temperatures of up to 350° C. to form polyazole polymers, C) application of a layer using the mixture from step A) and/or B) to a support, D) polymerization of the vinyl-containing phosphonic acid present in the sheet-like structure obtainable according to step C).

Abstract: A method for forming a mixed metal coating on a gas diffusion medium substantially free of ionomeric components which includes the steps of subjecting an electrically conductive web to a first ion beam having an energy not higher than 500 eV, then to a second beam having an energy of at least 500 eV containing the ions of a first metal, and to at least a third beam having an energy of at least 500 eV containing the ions of a noble metal. The invention also relates to gas diffusion electrodes.

Abstract: The present invention relates to a proton-conducting multilayer electrolyte membrane with a barrier layer, a process for producing it and a fuel cell containing such a membrane.

Abstract: The present invention relates to a proton-conducting polymer membrane which comprises polyazoles and is coated with a catalyst layer and is obtainable by a process comprising the steps A) preparation of a mixture comprising polyphosphoric acid, at least one polyazole (polymer A) and/or one or more compounds which are suitable for forming polyazoles under the action of heat according to step B), B) heating of the mixture obtainable according to step A) under inert gas to temperatures of up to 400° C., C) application of a layer using the mixture obtained according to step A) and/or B) to a support, D) treatment of the membrane formed in step C) until it is self-supporting, E) application of at least one catalyst-containing coating to the membrane formed in step C) and/or in step D).

Abstract: The present invention relates to a proton-conducting multilayer electrolyte membrane with a barrier layer, a process for producing it and a fuel cell containing such a membrane.