Degussa Aktiengesellschaft

Umicore Ag & Co Kg

Degussa - Huls Ag

Ferro Corporation

Degussa-huls Aktiengellschaft

Karl-Anton Starz

Knut Fehl

Ralf Zuber

Joachim Köhler

Thomas Lehmann

Sandra Wittpahl

Robert Schwarz

Dan V Goia

Manfred Diehl

Andreas Freund

Peter Biberbach

Emmanuel Auer

Udo Stenke

Karsten Ruth

Joachim Koehler

Anita Krämer

Volker Bänisch

Gerhard Heinz

Ralf Karch

Stipan Katusic

Werner Hartmann

Wolfgang Weber

Ralph McIntosh

Hans-Hermann Beyer

Hauke Jacobsen

J&uuml;rgen Koch

Armin Bayer

Leander Staab

Wolfgang Kohlweiler

Klaus Lutz

Willi Peter

Hans-Joachim Baer

Werner Leske

Harry Mueller

Mathias Metzner

Wolfgang G&ouml;ttenauer

Joachim Kohler

Anita Kramer

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.

Noble metal nanoparticles, a process for preparing these and their use

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&#xb0; C. and is present in the ink in a concentration between 1 and 50 wt. %, with respect to the weight of water.

Ink for producing membrane electrode assemblies for fuel cells

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.

Method for the production of membrane electrode assemblies for fuel cells

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.

Noble metal-containing supported catalyst and a process for its preparation

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.

Process for producing a membrane electrode assembly for fuel cells

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.

Process for producing a membrane electrode assembly and the membrane electrode assembly produced thereby

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&deg; C. The catalyst is characterised by a high tolerance to carbon monoxide poisoning in the fuel cell.

Process for preparing an anode catalyst for fuel cells and the anode catalyst prepared therewith

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.

Soldering paste for hard-soldering and coating aluminum and aluminum alloys

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.

Coating composition for producing electrically conductive coatings

A process is disclosed for applying electrode layers to a polymer electrolyte membrane strip in a desired pattern, wherein the front and back of the membrane are continuously printed with the electrode layers in the desired pattern using an ink containing an electrocatalyst, and the printed electrode layers are dried at elevated temperature immediately after the printing operation, the printing taking place while maintaining accurate positioning of the patterns of the electrode layers on the front and back in relation to one another.

Process for applying electrode layers to a polymer electrolyte membrane strip for fuel cells

A membrane-electrode unit for polymer-electrolyte fuel cells. The membrane-electrode unit consists of a polymer electrolyte membrane and porous reaction layers applied to both sides comprising a catalyst and a proton-conducting polymer, a so-called ionomer. The membrane-electrode unit is characterized in that one part A,of the catalyst of the reaction layers is saturated with the ionomer and is embedded in the ionomer whereas one part A,of the catalyst is kept free from the ionomer, where the parts A,and A,are in a weight ratio of 1:1 to 20:1.

Membrane-electrode unit for polymer electrolyte fuel cells and processes for their preparation

A platinum alloy catalyst on an electrically conductive carbon support which contains an alloy of 40 to 60 atom-% of platinum, 10 to 20 atom-% of rhodium and 20 to 50 atom-% of iron in the form of finely divided alloy particles. The catalyst is characterised in that the average particle size of the alloy particles is less than 10 nm.

Pt/Rh/Fe alloy catalyst for fuel cells and a process for producing the

A catalyst layer on a substrate material which contains a proton-conducting polymer (ionomer), electrically conductive carbon particles and fine particles of at least one precious metal. The catalyst layer is obtainable by coating the substrate material with an ink which contains a dispersion of the carbon particles and at least one organic precious metal complex compound in a solution of the ionomer, and drying the coating below a temperature at which the ionomer or the substrate material is thermally damaged, the precious metals in the complex compounds being present with an oxidation number of 0 and the complex compounds being thermally decomposed during drying to form the fine precious metal particles.

Catalyst layer for polymer electrolyte fuel cells

A platinum supported catalyst is disclosed for the anode in a PEM fuel cell with high resistance to poisoning by carbon monoxide. The catalyst contains the noble metals platinum and ruthenium on a finely divided, conductive support material. The two noble metals are not alloyed with each other and are present in highly dispersed form on the support material, wherein the crystallite size of the platinum is less than 2 nm and that of the ruthenium is less than 1 nm.

Co-tolerant anode catalyst for PEM fuel cells and a process for its

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Rodenbach, Germany

Karl-Anton Starz