| 摘要 |
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 H 2 Pt(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. The colloidal precious metal dispersions are essentially free of contaminants such as salts or surfactants and may further contain electrically conductive or non-conductive support materials. The colloidal precious metal dispersions can be used for the preparation of catalyst inks, ionomer layers, catalyst layers, electrodes or composite catalyst materials and find broad application in fuel cell technology (e.g. PEMFC, DMFC or water electrolysers). |
