Patent ID: 6383973
Filing Date: 2002-05-07
Classification: B01J,C07C

Abstract:
A complex oxide catalyst which is expressed by general formula (1):MoaWbBicFedAeBfCgDhEiOx in which Mo is molybdenum; W is tungsten; Bi is bismuth; Fe is iron; A is at least an element selected from nickel and cobalt; B is at least an element selected from sodium, potassium, rubidium, cesium and thallium; C is at least an element selected from alkaline earth metals; D is at least an element selected from phosphorus, tellurium, antimony, tin, cerium, lead, niobium, manganese, arsenic, boron and zinc; E is at least an element selected from silicon, aluminum, titanium and zirconium; and O is oxygen; a, b, c, d, e, f, g, h, i and x denote the atomic ratios of Mo, W, Bi, Fe, A, B, C, D, E and O, respectively; and where a is 12, 0&lE;b&lE;10, 0and x is determined by degree of oxidation of each of the elements, said catalyst being characterized in that it is prepared from an aqueous slurry comprising (i) bismuth nitrate and/or basic bismuth nitrate as bismuth-source compound, (ii) other source compounds for supplying other components than bismuth and (iii) nitric acid, in that the molar ratio of total nitrate anions (NO3) from any of said compounds and nitric acid in said aqueous slurry to molybdenum (Mo) in said aqueous slurry is adjusted to be more than 1 but not more than 1.8.