Umicore Ag & Co Kg

Studiengesellschaft Kohle Mbh

Solvicore Gmbh & Co Kg

Marco Lopez

Dan V Goia

Carsten Becker

Michael Lennartz

Peter Biberbach

Tapan Kumar Sau

Stéphanie Chevalliot

Mihaela-Ortansa Jitianu

Walter Behl

Manfred T Reetz

Ralf Zuber

Christoph Hengst

Rolf Hempelmann

Andreas Schleunung

Daniel Herein

Joachim Koehler

Harald Natter

Igor V Sevonkaev

Matthias Binder

Volker Baenisch

Barbara Klose-Schubert

Vivien Keller

The present invention relates to a method for preventing an SCR catalyst from being contaminated with platinum group metal in an emission control system comprising, upstream of the SCR catalyst, a catalyst that contains platinum group metal, characterized in that a material zone containing a mixture of aluminum oxide and cerium oxide is located upstream of the SCR catalyst.

Method for preventing a selective catalytic reduction (SCR) catalyst from being contaminated with platinum

The invention relates to a carbon-free electrocatalyst for fuel cells, containing an electrically conductive substrate and a catalytically active species, wherein the conductive substrate is an inorganic, multi-component substrate material of the composition 0X1-0X2, in which 0X1 means an electrically non-conductive inorganic oxide having a specific surface area (BET) in the range of 50 to 400 mVg and 0X2 means a conductive oxide. The non-conductive inorganic oxide 0X1 is coated with the conductive oxide 0X2. The multi-component substrate preferably has a core/shell structure. The multi-component substrate material 0X1-0X2 has an electrical conductivity in the range&#x3e;0.01 S/cm and is coated with catalytically active particles containing noble metal. The electrocatalysts produced therewith are used in electrochemical devices such as PEM fuel cells and exhibit high corrosion stability.

Electrocatalyst for fuel cells and method for producing said electrocatalyst

The present invention is directed to catalyst particles comprising a layered core-shell-shell structure and to a method of their manufacture. The catalyst particles have the general formula BM/IL/PM in which BM is a base metal core (selected from Co, Ni or Cu), PM is a precious metal outer shell (selected from Pt, Ir or Pd) and IL is an intermediate layer comprising a base metal/precious metal alloy with a concentration gradient of base metal to the outside PM layer. The particles of the present invention comprise a core-shell-shell structure and a substantially continuous precious metal shell layer. They find use in various catalytic applications, for example in gas-phase catalysis, in electrocatalysts for fuel cells, in catalytic converters for automobiles and in electronic or medical applications.

Catalyst particles comprising a layered core-shell-shell structure and method of their manufacture

The invention discloses core/shell, type catalyst particles comprising a M/Mstructure with M=inner particle core and M=outer particle shell, wherein the medium diameter of the catalyst particle (d) is in the range of 20 to 100 nm, preferably in the range of 20 to 50 nm. The thickness of the outer shell (t) is about 5 to 20% of the diameter of the inner particle core of said catalyst particle, preferably comprising at least 3 atomic layers. The core/shell type catalyst particles, particularly the particles comprising a Pt&#x2dc;based shell reveal a high specific activity. The catalyst particles are preferably supported on suitable support materials such as carbon black and are used as electrocatalysts for fuel cells.

Core/shell-type catalyst particles and methods for their preparation

The invention discloses core/shell type catalyst particles comprising a M/Mstructure with M=inner particle core and M=outer particle shell, wherein the medium diameter of the catalyst particle (d) is in the range of 20 to 100 nm, preferably in the range of 20 to 50 nm. The thickness of the outer shell (t) is about 5 to 20% of the diameter of the inner particle core of said catalyst particle, preferably comprising at least 3 atomic layers. The core/shell type catalyst particles, particularly the particles comprising a Pt-based shell, reveal a high specific activity. The catalyst particles are preferably supported on suitable support materials such as carbon black and are used as electrocatalysts for fuel cells.

The invention discloses core/shell type catalyst particles comprising a M/Mstructure with M=inner particle core and M&#x2212;outer particle shell, wherein the medium diameter of the catalyst particle (d) is &#x2267;20 nm. The thickness of the outer shell (t) comprises at least 3 atomic layers. The core/shell type catalyst particles, particularly the particles comprising a Pt-based shell, reveal a high specific activity. The catalyst particles are preferably supported on suitable support materials such as carbon black and are used as electrocatalysts for fuel cells.

The invention provides a method for manufacturing supported noble metal based alloy catalysts with a high degree of alloying and a small crystallite size. The method involves using polyol solvents as reaction medium and comprises a two-step reduction process in the presence of a support material. In the first step, the first metal (transition metal; e.g. Co, Cr, Ru) is activated by increasing the reaction temperature to 80 to 160&#xb0; C. In the second step, the second metal (noble metal; e.g. Pt, Pd, Au) is added and the slurry is heated to the boiling point of the polyol solvent in a range of 160 to 300 &#xb0; C. The catalysts manufactured according to the method are used as electrocatalysts for polymer electrolyte membrane fuel cells (PEMFC), direct-methanol fuel cells (DMFC) or as gas phase catalysts for CO oxidation or exhaust gas purification.

Method for manufacture of noble metal alloy catalysts and catalysts prepared therewith

The invention is directed to iridium oxide based catalysts for use as anode catalysts in PEM water electrolysis. The claimed composite catalyst materials comprise iridium oxide (IrO) and optionally ruthenium oxide (RuO) in combination with a high surface area inorganic oxide (for example TiO, AlO, ZrOand mixtures thereof). The inorganic oxide has a BET surface area in the range of 50 to 400 m/g, a water solubility of lower than 0.15 g/l and is present in a quantity of less than 20 wt. % based on the total weight of the catalyst. The claimed catalyst materials are characterized by a low oxygen overvoltage and long lifetime in water electrolysis. The catalysts are used in electrodes, catalyst-coated membranes and membrane-electrode-assemblies for PEM electrolyzers as well as in regenerative fuel cells (RFC), sensors, and other electrochemical devices.

Precious metal oxide catalyst for water electrolysis

The invention is directed to core/shell type catalyst particles comprising a M/Mstructure with M=inner particle core and M=outer particle shell, wherein the medium diameter of the catalyst particle (d+) is in the range of 20 to 100 nm, 5 preferably in the range of 20 to 50 nm. The thickness of the outer shell (t) is about 5 to 20% of the diameter of the inner particle core of said catalyst particle, preferably comprising at least 3 atomic layers. The inner particle core (M) of the particles comprises metal or ceramic materials, whereas the material of the outer shell (M) comprises precious metals and/or alloys thereof. The core/shell type catalyst particles are preferably supported on suitable support materials such as carbon black and can be used as electrocatalysts for fuel cells and for other catalytic applications.

Core / shell-type catalyst particles comprising metal or ceramic core materials and methods for their preparation

The invention relates to an ink for producing catalyst layers for electrochemical devices. The ink comprises catalyst materials, ionomer material, water and at least one organic solvent. The organic solvent belongs to the class of tertiary alcohols and/or the class of aliphatic diketones and bears functional groups which are stable to oxidative degradation in the ink. This prevents formation of decomposition products in the ink. The ink of the invention displays a high storage stability and is used for producing catalyst-coated substrates for electrochemical devices, in particular fuel cells (PEMFCs, DMFCs).

Ink for producing catalyst layers

The present invention provides a method for manufacture of supported noble metal based alloy catalysts with a high degree of alloying and a small crystallite size. The method is based on the use of polyol solvents as reaction medium and comprises of a two-step reduction process in the presence of a support material. In the first step, the first metal (M1=transition metal; e.g. Co, Cr, Ru) is activated by increasing the reaction temperature to 80 to 160&#xb0; C. In the second step, the second metal (M2=noble metal; e.g. Pt, Pd, Au and mixtures thereof) is added and the slurry is heated to the boiling point of the polyol solvent in a range of 160 to 300&#xb0; C. Due to this two-step method, an uniform reduction occurs, resulting in noble metal based catalysts with a high degree of alloying and a small crystallite size of less than 3 nm. Due to the high degree of alloying, the lattice constants are lowered. The catalysts manufactured according to the method are used as electrocatalysts for polymer electrolyte membrane fuel cells (PEMFC), direct-methanol fuel cells (DMFC) or as gas phase catalysts for CO oxidation or exhaust gas purification.

The invention is directed to iridium oxide based catalysts for use as anode catalysts in PEM water electrolysis. The claimed composite catalyst materials comprise iridium oxide (IrO) and optionally ruthenium oxide (RuO) in combination with a high surface area inorganic oxide (for example TiO, AlO, ZrOand mixtures thereof). The inorganic oxide has a BET surface area in the range of 50 to 400 m/g, a water solubility of lower than 0.15 g/l and is present in a quantity of less than 20 wt. % based on the total weight of the catalyst. The claimed catalyst materials are characterised by a low oxygen overvoltage and long lifetime in water electrolysis. The catalysts are used in electrodes, catalyst-coated membranes and membrane-electrode-assemblies for PEM electrolyzers as well as in regenerative fuel cells (RFC), sensors, and other electrochemical devices.

The invention relates to an ink for producing catalyst layers for electrochemical devices. The ink comprises catalyst material, ionomer material, water and at least one organic solvent. The organic solvent belongs to the class of tertiary alcohol's and/or the class of aliphatic diketones and bears functional groups which are stable to oxidative degradation in the ink. This prevents formation of decomposition products in the ink. The ink of the invention displays a high storage stability and is used for producing catalyst-coated substrates for electrochemical devices, in particular fuel cells (PEMFCs, DMFCs).

The invention relates to a carbon-supported PtRu anode catalyst for direct methanol fuel cells (DMFC) which has a platinum/ruthenium content in the range from 80 to 98 wt. %, preferably in the range from 85 to 98 wt. %, particularly preferably in the range from 85 to 95 wt. % (based on the total weight of the catalyst), on a carbon-based electrically conductive support material and has a mean particle size of less than 3 nm. The catalyst is prepared using a carbon black support material having a specific surface area (measured by the BET method) in the range from 1000 to 2000 m/g by means of a reduction process using chemical reducing agents with addition of organic acids. Electrodes and membrane-electrode units containing the catalyst according to the invention having a high precious metal loading have an electrode layer thickness of less than 80 &#x3bc;m at a PtRu loading per unit area of the electrode of from 6 to 12 mg of PtRu/cmand lead to improved electric power in direct methanol fuel cells.

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Frankfurt-am-Main, Germany

Marco Lopez