431-86-7Relevant articles and documents
Copper-Substituted Chromium Oxide Compositions, Their Preparation, and Their Use as Catalysts and Catalyst Precursors
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Page/Page column 11, (2010/06/22)
A crystalline alpha-chromium oxide where from about 0.05 atom % to about 5 atom % of the chromium atoms in the alpha-chromium oxide lattice are replaced by divalent copper (Cu+2) atoms is disclosed. Also disclosed is a chromium-containing catalyst composition comprising as a chromium-containing component the crystalline copper-substituted alpha-chromium oxide; and methods for preparing a composition comprising the crystalline copper-substituted alpha-chromium oxide. One method involves (a) co-precipitating a solid by adding ammonium hydroxide to an aqueous solution of a soluble copper salt and a soluble trivalent chromium salt that contains at least three moles of nitrate per mole of chromium in the solution and has a copper concentration of from about 0.05 atom % to about 5 atom % of the total concentration of copper and chromium in the solution; and after at least three moles of ammonium per mole of chromium in the solution has been added to the solution, (b) collecting the co-precipitated solid formed in (a); (c) drying the collected solid; and (d) calcining the dried solid. Another method involves (a) preparing an aqueous solution of a soluble copper salt and a soluble trivalent chromium salt that contains a copper concentration of from about 0.05 atom % to about 5 atom % of the total concentration of copper and chromium in the solution, (b) evaporating the solution to dryness, and (c) calcining the dried solid. Also disclosed is a chromium-containing catalyst composition comprising a chromium-containing component prepared by treating the crystalline copper-substituted alpha-chromium oxide with a fluorinating agent; and a process for changing the fluorine distribution (i.e., content and/or arrangement) in a hydrocarbon or halogenated hydrocarbon in the presence of a catalyst. The process involves using as the catalyst a composition comprising the crystalline copper-substituted alpha-chromium oxide and/or the treated copper-substituted alpha-chromium oxide.
Preparation of composition containing chromium, oxygen, and either silver or palladium, and their use as catalysts and catalyst precursors
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Page/Page column 8-9, (2008/12/08)
A method for preparing a catalyst composition suitable for increasing the fluorine content in a hydrocarbon or a halogenated hydrocarbon is disclosed. The method involves (a) co-precipitating a solid by adding ammonium hydroxide to an aqueous solution of a soluble trivalent chromium salt and a soluble salt of a modifier metal selected from silver and palladium, that contains at least three moles of nitrate (i.e., NO3?) per mole of chromium (i.e., Cr+3) in the solution and has a modifier metal concentration of from about 0.05 atom % to about 10 atom % of the total concentration of modifier metal and chromium in the solution to form an aqueous mixture containing co-precipitated solid and dissolved ammonium nitrate; and after at least three moles of ammonium hydroxide per mole of chromium in the solution has been added to the solution, (b) drying said aqueous mixture formed in (a); and (c) calcining the dried solid formed in (b) in an atmosphere containing at least 10% oxygen by volume (e.g., air). Also disclosed is a catalyst composition comprising alpha-chromium oxide and a modifier metal selected from silver and palladium prepared by the above method. Also disclosed is a process for increasing the fluorine content in a hydrocarbon or halogenated hydrocarbon in the presence of a catalyst; and processes using a catalyst composition comprising chromium, oxygen and a modifier metal selected from siver and palladium as essential constituent elements (e.g., a catalyst composition prepared by the above process). An azeotropic composition involving CF3CCl═CF2 and HF is also disclosed.
Compositions containing chromium, oxygen, and at least two modifier metals selected the group consisting of gold, silver, and palladium, their preparation, and their use as catalysts and catalyst precursors
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Page/Page column 12-13, (2008/12/08)
A catalyst composition is disclosed that includes chromium, oxygen, and at least two of gold, silver, and palladium as essential constituent elements. The amount of modifier metals (gold, silver, and/or palladium) in the composition is from about 0.05 atom % to about 10 atom % based on the total amount of chromium and modifier metals. Also disclosed is a process for changing the fluorine distribution (i.e., content and/or arrangement) in a hydrocarbon or halogenated hydrocarbon in the presence of the catalyst composition; and methods for preparing said catalyst composition. One preparation method involves (a) co-precipitating a solid by adding ammonium hydroxide (aqueous ammonia) to an aqueous solution of soluble salts of modifier metals and a soluble chromium salt that contains at least three moles of nitrate per mole of chromium in the solution and has a modifier metal content of from about 0.05 atom % to about 10 atom % of the total content of modifier metals and chromium in the solution to form an aqueous mixture containing co-precipitated solid; (b) drying the co-precipitated solid formed in (a); and (c) calcining the dried solid formed in (b) in an atmosphere containing at least 10% oxygen by volume. Another preparation method involves (a) impregnating solid chromium oxide with a solution of a soluble modifier metal salts; (b) drying the impregnated chromium oxide prepared in (a); and optionally; (c) calcining the dried solid. Yet another preparation method involves mixing multiple compositions, each comprising chromium, oxygen, and at least one modifier metal.
