Abstract: The invention relates to membrane-electrode assemblies for the electrolysis of water (electrolysis MEAs), which contain an ion-conducting membrane having a front and rear side; a first catalyst layer on the front side; a first gas diffusion layer on the front side; a second catalyst layer on the rear side, and a second gas diffusion layer on the rear side. The first gas diffusion layer has smaller planar dimensions than the ion-conducting membrane, whereas the second gas diffusion layer has essentially the same planar dimensions as the ion-conducting membrane (“semi-coextensive design”). The MEAs also comprise an unsupported free membrane surface that yields improved adhesion properties of the sealing material. The invention also relates to a method for producing the MEA products. Pressure-resistant, gastight and cost-effective membrane-electrode assemblies are obtained, that are used in PEM water electrolyzers, regenerative fuel cells or in other electrochemical devices.

Abstract: The present invention provides ruthenium compounds of the formula The compounds of the invention occur in the form of two isomers: trans and cis. The method of production of the compounds according to the invention is based on reacting an intermediate of formula (5) with a carbene complex of ruthenium. The invention also relates to the use of the compounds according to the invention for carrying out metathesis reactions.

Abstract: The invention discloses core/shell type catalyst particles comprising a Mcore/Mshell structure with Mcore=inner particle core and Mshell=outer particle shell, wherein the medium diameter of the catalyst particle (dcore+shell) is in the range of 20 to 100 nm, preferably in the range of 20 to 50 nm. The thickness of the outer shell (tshell) 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.

Abstract: The invention discloses core/shell type catalyst particles comprising a Mcore/Mshell structure with Mcore=inner particle core and Mshell?outer particle shell, wherein the medium diameter of the catalyst particle (dcore+shell) is ?20 nm. The thickness of the outer shell (tshell) 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.

Abstract: 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° 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 ° 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.

Abstract: The invention is directed to core/shell type catalyst particles comprising a Mcore/Mshell structure with Mcore=inner particle core and Mshell=outer particle shell, wherein the medium diameter of the catalyst particle (dcore+shell) 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 (tshell) 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 (Mcore) of the particles comprises metal or ceramic materials, whereas the material of the outer shell (Mshell) 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.

Abstract: 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).

Abstract: The present invention relates to a process for the concentration of noble metals from fluorine-containing components of fuel cells, for example from PEM fuel cell stacks, DMFC fuel cells, catalyst-coated membranes (CCMs), membrane electrode assemblies (MEAs), catalyst pastes, etc. The process is based on an optionally multi-step heat treatment process comprising a combustion and/or a melting process. It allows an inexpensive, simple concentration of noble materials. The hydrogen fluoride formed during the heat treatment of fluorine-containing components is bound by an inorganic additive so that no harmful hydrogen fluoride emissions occur. The process can be used for the recovery of noble metals that are present as components in fuel cells, electrolysis cells, batteries, and the like.

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-coated ion-conducting membrane and a membrane-electrode assembly (MEA) for electrochemical devices, in particular for fuel cells. The catalyst-coated, ion-conducting membrane is provided with a sealing material which is applied in the edge region to one side of the membrane and has a thickness which corresponds to at least the total thickness of the catalyst-coated membrane. Owing to their simple, material-conserving construction, the catalyst-coated ion-conducting membranes and the membrane-electrode assemblies produced therefrom can be manufactured inexpensively. They are used in PEM fuel cells, direct methanol fuel cells (DMFCs), electrolyzers and other electrochemical devices.

Abstract: The present invention relates to the field of electrochemical cells and fuel cells, and more specifically to polymer-electrolyte-membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFC). It is directed to catalyst-coated ionomer membranes (“CCMs”) and membrane-electrode-assemblies (“MEAs”) that contain one or more protective film layers for protection, sealing and better handling purposes. The one or more protective film layers are attached to the surface of said catalyst-coated membranes in such a way that they overlap with a region of the passive non-coated ionomer area, and with a region of the active area that is coated with a catalyst layer. Furthermore, the present invention discloses a process for manufacture of CCMs and MEAs that contain protective film layers. The materials may be used as components for the manufacture of low temperature fuel cell stacks.

Abstract: 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° 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° 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.

Abstract: The invention relates to membrane-electrode assemblies for the electrolysis of water (electrolysis MEAs), which contain an ion-conducting membrane having a front and rear side; a first catalyst layer on the front side; a first gas diffusion layer on the front side; a second catalyst layer on the rear side, and a second gas diffusion layer on the rear side. The first gas diffusion layer has smaller planar dimensions than the ion-conducting membrane, whereas the second gas diffusion layer has essentially the same planar dimensions as the ion-conducting membrane (“semi-coextensive design”). The MEAs also comprise an unsupported free membrane surface that yields improved adhesion properties of the sealing material. The invention also relates to a method for producing the MEA products. Pressure-resistant, gastight and cost-effective membrane-electrode assemblies are obtained, that are used in PEM water electrolyzers, regenerative fuel cells or in other electrochemical devices.

Abstract: 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).