Method of synthesizing high surface area unagglomerated noble metal pyrochlore compounds
US4440670A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1982 |
| Grant date | Apr 3, 1984 |
| Priority date | — |
| Expiry date | Sep 30, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01G55/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of preparing electrically conductive pyrochlore compounds of high surface area and unagglomerated form, having the formula EQU A.sub.2 [B.sub.2-x A.sub.x ]O.sub.7-y is disclosed wherein A is selected from lead, bismuth and mixtures thereof, B is selected from ruthenium, iridium and mixtures thereof, 0<x.ltoreq.1.0 and 0.ltoreq.y.ltoreq.1. The method involves (1) synthesizing the pyrochlores in an aqueous alkaline reaction medium having a pH of at least about 12.0 and in the presence of an oxygen source (2) displacing the reaction medium with water, (3) atomizing the resultant slurry and (4) freeze drying the resultant product. The pyrochlore compounds thus prepared have a variety of applications including use as oxygen electrodes in electro-chemical devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.