Abstract: Nanoparticles which contain noble metals alone or noble metals in combination with base metals. The nanoparticles are embedded in an aqueous solution of a temporary stabilizer based on a polysaccharide.

Abstract: Nanoparticles which contain noble metals alone or noble metals in combination with base metals. The nanoparticles are embedded in an aqueous solution of a temporary stabilizer based on a polysaccharide.

Abstract: Nanoparticles which contain noble metals alone or noble metals in combination with base metals. The nanoparticles are embedded in an aqueous solution of a temporary stabilizer based on a polysaccharide.

Abstract: Nanoparticles which contain noble metals alone or noble metals in combination with base metals. The nanoparticles are embedded in an aqueous solution of a temporary stabilizer based on a polysaccharide.

Abstract: An ink is disclosed for producing membrane electrode assemblies for fuel cells which contains a catalyst material, an ionomer, water and an organic solvent. The ink is characterized in that the organic solvent is at least one compound from the group of linear dialcohols with a flash point higher than 100° C. and is present in the ink in a concentration between 1 and 50 wt. %, with respect to the weight of water.

Abstract: The present invention relates to a method for the production of a membrane electrode assembly comprising a polymer electrolyte membrane with two opposing membrane surfaces and a cathode and an anode electrode each comprising a catalyst layer and a gas distribution layer. Each catalyst layer is interposed between a membrane surface and the corresponding gas distribution layer. The catalyst layer of the cathode and/or the catalyst layer of the anode comprise at least two sub-layers. According to the present invention at least one of the sub-layers of the cathode electrode and/or the anode electrode is applied directly to the surface of the membrane while the remaining sub-layers are applied to the corresponding gas distribution layers. Finally the assembly of the coated membrane and the coated gas distribution layers is produced.

Abstract: The invention provides a noble metal-containing supported catalyst which contains one of the noble metals from the group Au, Ag, Pt, Pd, Rh, Ru, Ir, Os or alloys of one or more of these noble metals in the form of noble metal particles on a powdered support material. The particles deposited on the support material have a degree of crystallinity, determined by X-ray diffraction, of more than 2 and an average particle size between 2 and 10 nm. The high crystallinity and the small particle size of the noble metal particles lead to high catalytic activity for the catalyst. It is particularly suitable for use in fuel cells and for the treatment of exhaust gases from internal combustion engines.

Abstract: Nanoparticles which contain noble metals alone or noble metals in combination with base metals. The nanoparticles are embedded in an aqueous solution of a temporary stabilizer based on a polysaccharide.

Abstract: The invention relates to a catalyst-containing gas diffusion layer for fuel cells, in particular low-temperature fuel cells, e.g. PEMFCs and DMFCs. The gas diffusion layer is used on the anode side of the fuel cell and contains catalyst components which effect removal of carbon monoxide (in the PEMFC) or oxidation of methanol (in the DMFC). The catalyst components are produced directly in the porous substrate material from suitable precursor compounds by heat treatment and are distributed uniformly over the entire volume of the gas diffusion layer. As a result, the catalyst components have a particularly high activity. Furthermore, a process for producing a catalyst-containing gas diffusion layer is described. The gas diffusion layers are used in membrane-electrode units (MEUs) for low-temperature fuel cells, in particular for PEM fuel cells operated using a CO-containing reformate gas. They can also be used in direct methanol fuel cells (DMFCs).

Abstract: A process for producing a membrane electrode assembly for fuel cells containing a polymer electrolyte membrane having a first and a second surface parallel to each other. The first surface forms a firm composite with a first catalyst layer and a first water repellent gas distribution layer and said second surface form a firm composite with a second catalyst layer and a second water repellent gas distribution layer. The catalyst layers are prepared by using inks containing electrocatalysts, one or more solvents, proton-conducting ionomer and optionally water repelling agents and pore-forming agents. In the process the two catalyst layers are applied to or contacted with the respective surfaces of the polymer electrolyte membrane successively, wherein during the application or contacting process to one surface always the opposite surface of the membrane is supported.

Abstract: The invention comprises a process for making a membrane electrode assembly comprising a polymer electrolyte membrane having two opposite faces, on each face of which is applied a catalyst layer and a gas distribution layer. The two gas distribution layers in the membrane electrode assembly are formed by hydrophobized carbon substrates which, using appropriate inks containing at least one catalyst, dissolved ionomer and solvent, are each coated with a catalyst layer and are then laid on opposite faces of the polymer electrolyte membrane with the catalyst layers still in the moist state. Afterwards, a firm bond between electrolyte membrane, catalyst layers and carbon substrates is produced by treating the membrane electrode assembly at elevated temperature under pressure.

Abstract: The invention provides a noble metal-containing supported catalyst which contains one of the noble metals from the group Au, Ag, Pt, Pd, Rh, Ru, Ir, Os or alloys of one or more of these noble metals in the form of noble metal particles on a powdered support material. The particles deposited on the support material have a degree of crystallinity, determined by X-ray diffraction, of more than 2 and an average particle size between 2 and 10 nm. The high crystallinity and the small particle size of the noble metal particles lead to high catalytic activity for the catalyst. It is particularly suitable for use in fuel cells and for the treatment of exhaust gases from internal combustion engines.

Abstract: Furnace carbon black which has a hydrogen (H) content of greater than 4000 ppm and a peak integral ratio of non-conjugated H atoms (1250-2000 cm−1) to aromatic and graphitic H atoms (1000-1250 cm−1 and 750-1000 cm−1) of less than 1.22. The furnace carbon black is produced by injecting the liquid carbon black raw material and the gaseous carbon black raw material at the same point in a furnace carbon black process. The furnace carbon black may be used in the preparation of electrocatalysts.

Abstract: The invention provides a process for preparing a platinum-ruthenium catalyst and the catalyst prepared therewith. The catalyst can be supported on a support material in powder form or may also be unsupported. To prepare the supported catalyst, the support material is suspended in water and the suspension is heated to at most the boiling point. While keeping the temperature of the suspension the same, solutions of hexachloroplatinic acid and ruthenium chloride are then added to the suspension, then the pH of the suspension is increased to a value between 6.5 and 10 by adding an alkaline solution and the noble metals are thus precipitated onto the support material. Afterwards, one or more organic carboxylic acids and/or their salts are added to the suspension and the catalyst is chemically reduced, washed, dried and optionally subsequently calcined under an inert or reducing atmosphere at a temperature between 300 und 1000° C.

Abstract: A soldering paste for hard-soldering and coating working parts made of aluminum or aluminum alloys, which contains 25 to 35 percent in weight of a water-miscible organic binding agent on the basis of aliphatic glycols, 25 to 45 percent in weight of an aluminum hard-soldering powder, 25 to 45 percent in weight of an aluminum fluxing agent and, as an additive to influence the rheological properties, 0.01 to 0.2 percent by weight with respect to the total amount of one or several fatty acids with 10 to 20 C atoms and/or their ammonium salts.

Abstract: The present invention relates to a method for the production of a membrane electrode assembly comprising a polymer electrolyte membrane with two opposing membrane surfaces and a cathode and an anode electrode each comprising a catalyst layer and a gas distribution layer. Each catalyst layer is interposed between a membrane surface and the corresponding gas distribution layer. The catalyst layer of the cathode and/or the catalyst layer of the anode comprise at least two sub-layers. According to the present invention at least one of the sub-layers of the cathode electrode and/or the anode electrode is applied directly to the surface of the membrane while the remaining sub-layers are applied to the corresponding gas distribution layers. Finally the assembly of the coated membrane and the coated gas distribution layers is produced.

Abstract: A coating composition for producing electrically conductive coatings, containing one or more electrically conductive pigments and an organic binder, as well as, optionally, additives and auxiliary agents, in an aqueous solvent, which organic binder contains a copolymer dispersible in water and based on (meth)acrylate- and silylated, unsaturated monomers. The total content of organic solvents in the composition does not exceed 0.5% by weight. The coatings thus obtained are especially well-bonded and resistant to mechanical influences and to solvents, and exhibit suitable conductivity (sheet resistivity) values.

Abstract: The invention comprises a process for making a membrane electrode assembly comprising a polymer electrolyte membrane having two opposite faces, on each face of which is applied a catalyst layer and a gas distribution layer. The two gas distribution layers in the membrane electrode assembly are formed by hydrophobized carbon substrates which, using appropriate inks containing at least one catalyst, dissolved ionomer and solvent, are each coated with a catalyst layer and are then laid on opposite faces of the polymer electrolyte membrane with the catalyst layers still in the moist state. Afterwards, a firm bond between electrolyte membrane, catalyst layers and carbon substrates is produced by treating the membrane electrode assembly at elevated temperature under pressure.

Abstract: The invention provides a noble metal-containing supported catalyst which contains one of the noble metals from the group Au, Ag, Pt, Pd, Rh, Ru, Ir, Os or alloys of one or more of these noble metals in the form of noble metal particles on a powdered support material. The particles deposited on the support material have a degree of crystallinity, determined by X-ray diffraction, of more than 2 and an average particle size between 2 and 10 nm. The high crystallinity and the small particle size of the noble metal particles lead to high catalytic activity for the catalyst. It is particularly suitable for use in fuel cells and for the treatment of exhaust gases from internal combustion engines.

Abstract: The invention provides a process for preparing a platinum-ruthenium catalyst and the catalyst prepared therewith. The catalyst can be supported on a support material in powder form or may also be unsupported. To prepare the supported catalyst, the support material is suspended in water and the suspension is heated to at most the boiling point. While keeping the temperature of the suspension the same, solutions of hexachloroplatinic acid and ruthenium chloride are then added to the suspension, then the pH of the suspension is increased to a value between 6.5 and 10 by adding an alkaline solution and the noble metals are thus precipitated onto the support material. Afterwards, one or more organic carboxylic acids and/or their salts are added to the suspension and the catalyst is chemically reduced, washed, dried and optionally subsequently calcined under an inert or reducing atmosphere at a temperature between 300 und 1000° C.