Method for preparing dispersions of precious metal nanoparticles and for isolating such nanoparticles from said dispersions
US8529963B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2009 |
| Grant date | Sep 10, 2013 |
| Priority date | — |
| Expiry date | Nov 15, 2029 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB82Y30/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention is directed to a method for preparing colloidal dispersions of precious metal nanoparticles selected from the group consisting of Pt, Au, Pd, Ag, Rh, Ru and mixtures or alloys thereof, and to a method for isolating such precious metal nanoparticles from these colloidal dispersions. The colloidal dispersions are prepared by reducing suitable precious metal precursor compounds in aqueous alkaline solutions at reaction temperatures between 40 and 70° C. and a pH≧12.0 in the presence of polysaccharides with average molecular weights (Mw) in the range of 300,000 to 1,000,000. The precious metal nanoparticles are isolated after decomposing the polysaccharide by heating the colloidal dispersions to temperatures >80° C. The nanoparticles can be used for the manufacture of core/shell-type catalyst materials and for electronic, decorative and medical applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.