Chromium aerogel method of producing same and fluorinating process utilizing same
US4828818A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1987 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Nov 23, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/60
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Chromium(III) oxide and hydroxide aerogels are produced by the reaction of chromium(VI) oxide with a solvent which is reducing to chromium(VI), such as methanol, heating the solution to hypercritical conditions, and venting the solvent hypercritically. The product aerogels exhibit surface areas above 400 m.sup.2 /g, pore volumes of at least 2 cm.sup.3 /g and a substantially uniform pore size distribution. Also disclosed is a unique process which employs high pore volume, high surface area chromium(III) oxide or hydroxide as a fluorination catalyst. More particularly, reaction of C.sub.2 Cl.sub.3 F.sub.3 with HF over these catalysts produced high yields of C.sub.2 Cl.sub.2 F.sub.4 and C.sub.2 ClF.sub.5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.