Abstract: The invention relates to colloidal dispersions comprising nano-sized precious metal particles (e.g. platinum or platinum alloy particles) and at least one ionomer component having acidic groups. The method for its manufacturing is based on a neutralization and dissolving process of a suitable precious metal precursor compound with a liquid acidic ionomer component, followed by a reduction step. Suitable precious metal precursors consist of precious metal atoms, hydrogen atoms, oxygen atoms and optionally carbon atoms. Examples for precursors are H2Pt(OH)6, Pd(OH)2 or Ir(OH)4, preferred reducing agents are aliphatic alcohols or hydrogen. The invention further relates to pre-products for the manufacture of such colloidal dispersions, namely to compositions which contain precious metal precursors and at least one acidic ionomer compound.

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 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 present invention relates to water-based catalyst inks and their use for manufacture of catalyst-coated substrates. According to the present invention, a catalyst layer is applied to the hydrophobic surface of a substrate by using a water-based catalyst ink comprising an electrocatalyst, an ionomer and water. The catalyst ink also comprises a highly volatile surfactant having a vapor pressure at ambient temperature in the range of 1 to 600 Pa. The use of this surfactant allows applying the water-based ink to the hydrophobic surface of a variety of substrates, such as gas diffusion layers, advanced ionomer membranes and polymer substrates. The required coating deposit can be applied in one coating pass and the resulting catalyst layer exhibits improved performance due to the absence of residual surfactant in the catalyst layer.

Abstract: A gas diffusion structure for polymer electrolyte fuel cells having a sheet-like carbon substrate made hydrophobic and having two main opposing surfaces and a contact layer on one of these surfaces. The contact layer is formed of an intimate mixture of at least one hydrophobic polymer, which can be polyethylene, polypropylene or polytetrafluoroethylene, and finely divided carbon particles, wherein the weight percentage of the carbon particles relative to the total weight of the contact layer amounts to 40 to 90 wt. %. The gas diffusion structure is a carbon substrate made hydrophobic by at least one hydrophobic polymer and the hydrophobic polymers are restricted to two layers extending from both opposing surfaces into the carbon substrate down to a depth of from 5 to 40 &mgr;m and the hydrophobic polymers fill of from 20 to 60% of the pore volume within those layers.