CAS: 12001-99-9; Viridian 3B

专利信息

专利号:US-4428852-A
优先权日:1982-01-18
标题:Continuous synthesis of chromium dioxide
发明人：COVINGTON JR ROBERT A; LONG CECIL L; WILLISTON DAVID W
权利人:DU PONT
摘要:Ferromagnetic chromium dioxide is produced in a continuous operation by feeding a preheated paste of hydrated chromium oxides and additives into a twin screw reactor, reacting at elevated temperature and pressure for a short time while venting oxygen and steam, injecting water near the end of the reaction zone to form a viscous chromium dioxide-water mixture, and cooling while passing through a pressure letdown extruder.

专利号:US-7211607-B2
优先权日:2002-04-24
标题:Method for producing high surface area chromia materials for catalysis
发明人：GASH ALEXANDER E; SATCHER JOE; TILLOTSON THOMAS; HRUBESH LAWRENCE; SIMPSON RANDALL
权利人:UNIV CALIFORNIA
摘要:Nanostructured chromium(III)-oxide-based materials using sol-gel processing and a synthetic route for producing such materials are disclosed herein. Monolithic aerogels and xerogels having surface areas between 150 m 2 /g and 520 m 2 /g have been produced. The synthetic method employs the use of stable and inexpensive hydrated-chromium(III) inorganic salts and common solvents such as water, ethanol, methanol, 1-propanol, t-butanol, 2-ethoxy ethanol, and ethylene glycol, DMSO, and dimethyl formamide. The synthesis involves the dissolution of the metal salt in a solvent followed by an addition of a proton scavenger, such as an epoxide, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively.