A crystalline alpha-chromium oxide where from about 0.05 atom % to about 2
atom % of the chromium atoms in the alpha-chromium oxide lattice are
substituted by nickel atoms, and optionally, additional chromium atoms in
the alpha-chromium oxide lattice are substituted by trivalent cobalt
atoms (provided that the total amount of the nickel atoms and the
trivalent cobalt atoms in the alpha-chromium oxide lattice is no more
than 6 atom %) is disclosed. Also disclosed is a chromium-containing
catalyst composition comprising as a chromium-containing component the
crystalline substituted alpha-chromium oxide; and a method for preparing
a composition comprising the crystalline substituted alpha-chromium
oxide. The method comprises (a) co-precipitating a solid by adding
ammonium hydroxide to an aqueous solution of a soluble divalent nickel
salt, a soluble trivalent chromium salt, and optionally, a soluble
divalent or trivalent cobalt salt, that contains at least three moles of
nitrate per mole of chromium in the solution, has a nickel concentration
of from about 0.05 mole % to about 2 mole % of the total of nickel,
chromium, and cobalt in the solution, and has a combined concentration of
nickel and cobalt of no more than 6 mole % of the total of nickel,
chromium, and cobalt in the solution; and after at least three moles of
ammonium per mole of chromium 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. Also disclosed is a
chromium-containing catalyst composition comprising a chromium-containing
component prepared by treating said crystalline 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 substituted alpha-chromium oxide and/or the treated
substituted alpha-chromium oxide.