Abstract:
A process for preparing acrylonitrile comprises ammoxidising propylene in the presence of a complex oxide catalyst having the empirical formula:
A a B b C c D d Fe e Bi f Mo 12 O x
where A is Cs, K or mixtures thereof B is one or more of Mg, Mn, Ni, Co, Ag, Pb, Re, Cd and Zn or mixtures thereof C is one or more of Ce, Cr, P, Ge and mixtures thereof D is Ca and optionally one of Sr, Ba or mixtures thereof and a = 0.01 to 1.0 b and e = 1.0 to 10 c, d and f = 0.1 to 5.0 and x is a number determined by the valence requirements of the other elements present.
Abstract:
Antimony-based oxide complex catalysts are improved by adding to these catalysts an antimony-containing compound such as Sb 2 O 3 , in an amount of 0.1 to 25% based on an atomic basis of the antimony relative to the antimony already present in the catalyst. In this way a catalyst is produced which gives improved yields for example in the procuction of acrylonitrile by the ammoxidation of propylene.
Abstract:
A slurry process for producing a fluid-bed catalyst comprising an antimonate-based oxide complex supported on a catalyst support in which (1) source compounds containing all of the elements of said oxide complex and said support material are combined to form a pre-catalyst slurry, (2) the liquid removed from said pre-catalyst slurry to form a pre-catalyst, and (3) said pre-catalyst is heated at elevated temperature to form said catalyst, in which the support material combined with the source compounds in step (1) is composed of (a) a fumed catalyst support material, such as fumed silica, and (b) a catalyst support material sol, such as a silica sol. The pre-catalyst slurry is formed without the addition of a slurry-derived solid containing fumed catalyst support material and one or more of the source compounds. The process is preferably a single slurry process. The catalyst produced has improved catalytic properties and attrition resistance.
Abstract:
Antimony-based oxide complex catalysts are improved by adding to these catalysts an antimony-containing compound such as Sb 2 O 3 , in an amount of 0.1 to 25% based on an atomic basis of the antimony relative to the antimony already present in the catalyst. In this way a catalyst is produced which gives improved yields for example in the procuction of acrylonitrile by the ammoxidation of propylene.
Abstract:
A catalyst comprising an oxide complex of the general formula in which A represents Cu, Ce, U, V, Cr, Mn and/or Te; B represents an alkali metal, alkaline earth metal, Co, Ni, Zn, Cd, rare earth, Ga, TI and/or Th; C represents Mo, W, Nb, Ta, Sn, Ge, Ti, Zr, P, B, and/or As; a is 0 - 20; b is 0 - 20; c is 0 - 20; a+b+c is greater than 0 and x is a number determined by the oxygen requirements of the other elements present. The catalysts are useful in the production of nitriles by the vapour phase ammoxidation of olefins, aldehydes and alcohols; the vapour phase oxidation of olefins containing not more than three contiguous carbon atoms and the vapour phase oxydehydrogenation of olefins containing four or more contiguous carbon atoms. A particularly preferred catalyst according to the invention has the formula W 0.2 Mo 1 Bi 2 Cu 3 Fe 12 O x .
Abstract:
A process for regenerating molybdenum containing ammoxidation catalyst comprising replacing the molybdenum loss from the catalyst during the ammoxidation reaction wherein ammonium dimolybdenum is utilized as the source for replacement of the molybdenum loss from the original catalyst.
Abstract:
A process for improving the catalytic properties of a substantially crystalline iron bismuth molybdate oxide complex interim catalyst comprises incorporating at least one element from Groups IA, IB, IIB, IIIA and IIIB of the periodic Table into the catalyst by impregnation, none of the Group IA elements incorporated into the catalyst by impregnation being derived from a molybdate or silicate. The catalysts provide improved results in oxidation type reactions.
Abstract:
A bismuth cerium molybdate catalysts oxide complex catalyst contains a promoting amount of an alkali metal TI, Sm, Ag, Cu, Cr, Sb, rare earth metal other than Ce and Sm, Te, Ti, Zr, Th or mixture thereof. Such catalyst provides high yields of acrylonitrile in the ammoxidation of propylene and give improved results in other oxidation-type reactions.
Abstract:
A process for producing a molybdate or tungstate activated oxide complex catalyst in which the elements of the catalyst are combined together in a precatalyst aqueous slurry, the slurry obtained is dried to form a precatalyst precipitate, and the precatalyst precipitate is then calcined to form the catalyst, characterised in that the key catalytic phase of the catalyst defined as a molybdate or tungstate of Bi, Te, Sb, Sn, Cu or mixtures thereof is preformed prior to combining with the other elements of the catalyst, provided that when one or more elements in the catalyst is supplied to the precatalyst aqueous slurry in the form of (a) a source salt having a heat-decomposable cation or anion, (b) an inorganic salt reaction product of the source salt or (c) an aqueous slurry of either (a) or (b) then the elements of the catalyst are combined so that the precatalyst precipitate contains a substantial amount of at least one of the heat-decomposable anions or cations. The catalysts produced by this process are useful in the oxidation and ammoxidation of dlefins.