Abstract: The invention relates to a membrane electrode unit (MEU) for electrochemical apparatuses, in particular for direct methanol fuel cells (DMFC). The membrane electrode unit contains backings (i.e. gas diffusion layers) on the anode side and cathode side, which have a different water tightness (WT). The anode backing must have a lower water tightness (i.e. a higher water permeability) than the cathode backing, where WTAnode<WTCathode. The anode backing preferably has no compensating layer (microlayer), has a lower content of water repellent (from 2 to 10 wt.-%, based on the total weight) and has a higher total pore volume (VTot) than the cathode backing. The membrane electrode units produced have a substantially improved performance in DMFC fuel cells which are operated with aqueous methanol solution.

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: The invention relates to a process for recycling fuel cell components containing fluorine-containing and precious metal-containing constituents: in this process, the fluorine-containing constituents are separated off from the precious metal-containing constituents by treatment with a medium present in the supercritical state. Preference is given to using water as supercritical medium. After the fluorine-containing constituents have been separated off, the precious metal-containing residues can be recovered in a recycling process without harmful fluorine or hydrogen fluoride emissions. The fluorine-containing constituents can likewise be recovered. The process is used in the recovery of precious metals and/or fluorine-containing constituents from membrane fuel cells, electrolysis cells, batteries, sensors and other electrochemical devices.

Abstract: The invention describes a process for producing a gas diffusion electrode which has a catalyst layer having a smooth surface, wherein the smooth surface of the catalyst layer is produced by bringing the catalyst layer in the moist state into contact with a transfer film and removing this transfer film after drying. In variant A, the catalyst layer is firstly produced on a transfer film and then transferred in the moist state to the gas diffusion layer. In variant B, the catalyst layer is applied to the gas diffusion layer, and a transfer film is then placed on top. In both cases, the structure produced in this way is subsequently dried. Before further processing, the transfer film is removed to give a gas diffusion electrode having a smooth catalyst surface which has a maximum profile peak height (Rp) of less than 25 microns. The electrodes are used for producing membrane-electrode assemblies for membrane fuel cells or other electrochemical devices.

Abstract: A steering column switch, especially for a motor vehicle, contains a switch lever, which is activated transversely and which has a magnetic signal transmitter, to which several stationary magnetic-field sensors coupled to an evaluation unit are allocated for determining the switch positions of the switch lever. The switch lever supports a rotary switch and the signal transmitter and also the magnetic-field sensors are used for determining the switch positions of the rotary switch.

Abstract: The invention relates to a process for recycling fuel cell components containing fluorine-containing and precious metal-containing constituents: in this process, the fluorine-containing constituents are separated off from the precious metal-containing constituents by treatment with a medium present in the supercritical state. Preference is given to using water as supercritical medium. After the fluorine-containing constituents have been separated off, the precious metal-containing residues can be recovered in a recycling process without harmful fluorine or hydrogen fluoride emissions. The fluorine-containing constituents can likewise be recovered. The process is used in the recovery of precious metals and/or fluorine-containing constituents from membrane fuel cells, electrolysis cells, batteries, sensors and other electrochemical devices.

Abstract: A steering column switch, especially for a motor vehicle, contains a switch lever, which is activated transversely and which has a magnetic signal transmitter, to which several stationary magnetic-field sensors coupled to an evaluation unit are allocated for determining the switch positions of the switch lever. The switch lever supports a rotary switch and the signal transmitter and also the magnetic-field sensors are used for determining the switch positions of the rotary switch.

Abstract: The invention relates to a membrane electrode unit (MEU) for electrochemical apparatuses, in particular for direct methanol fuel cells (DMFC). The membrane electrode unit contains backings (i.e. gas diffusion layers) on the anode side and cathode side, which have a different water tightness (WT). The anode backing must have a lower water tightness (i.e. a higher water permeability) than the cathode backing, where WTAnode<WTCathode. The anode backing preferably has no compensating layer (microlayer), has a lower content of water repellent (from 2 to 10 wt.-%, based on the total weight) and has a higher total pore volume (VTot) than the cathode backing. The membrane electrode units produced have a substantially improved performance in DMFC fuel cells which are operated with aqueous methanol solution.

Abstract: The invention relates to a process for producing a five-layer membrane-electrode unit comprising an ionomer membrane, a first catalyst layer, a second catalyst layer, a first gas diffusion layer and a second gas diffusion layer. In the process of the invention, at least one gas diffusion layer is provided with a suitable perforation grid before or after coating with the catalyst. The excess gas diffusion material is removed as pressed screen after lamination of the gas diffusion layer onto the membrane, exposing the uncoated membrane areas. The process is suitable for the continuous production of five-layer membrane-electrode units of type 1 (in which the membrane forms a rim projecting beyond the two gas diffusion layers) and of type 3 (in which gas diffusion layers and membrane have a step-like, semicoextensive design). Two process variants in which dried and undried (i.e. solvent-containing) catalyst layers are laminated onto the membrane are described.

Abstract: The invention relates to membrane electrode units (MEUs) for membrane fuel cells. The products contain different gas diffusion layers on the anode side and on the cathode side. The amount of the water repellant agent (WRA) in the anode gas diffusion layer is identical or higher than the amount of water repellant agent in the cathode gas diffusion layer and is in the range of 20 to 35% by weight (based on total weight of the gas diffusion layer). At the same time, the total pore volume V of the cathode gas diffusion layer is higher than the total pore volume of the anode gas diffusion layer (Vcathode>VAnode). The membrane electrode units as well as the PEM stacks made therewith show improved performance when operated with unhumidified operating gases (such as dry hydrogen, reformate gas, oxygen or air).

Abstract: A rotary/pull switch , in particular a light switch for a motor vehicle, includes an actuating element having a base and axle that is guided in a housing. A permanent magnet is associated with the axle and several magnetic field sensors are associated with the base for determining the switching positions of the actuating element.

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.