Chromium aerogel method of producing same and fluorinating process utilizing same

摘要

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 m2/g, pore volumes of at least 2 cm3/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 C2Cl3F3 with HF over these catalysts produced high yields of C2Cl2F4 and C2ClF5.