PROCESS FOR PREPARING A MULTIELEMENT OXIDE COMPRISING BISMUTH AND TUNGSTEN BY COPRECIPITATION

摘要

Shaped catalyst bodies comprising a multielement oxide I having the general stoichiometry I [Bi1WbOx]a[Mo12Z1cZ2dFeeZ3fZ4gZ5hOy]1 (I), where Z1=Ni or Co, Z2=alkali metal or alkaline earth metal, Z3=zinc, phosphorus, arsenic, boron, antimony, tin, cerium, vanadium, chromium or bismuth, Z4=silicon, aluminum, titanium, tungsten or zirconiurn, Z5=copper, silver, gold, yttrium, lanthanum and lanthanides, a=0.1 to 3, b=0.1 to 10, c=1 to 10, d=0.01 to 2, e=0.01 to 5, f=0 to 5, g=0 to 10, h=0 to 1 and x, y=numbers determined by the valence and abundance of the elements other than oxygen in I, as active composition are produced by preforming a mixed oxide Bi1WbOx by coprecipitation from an aqueous environment at a pH in the range from 1.5 to 3 and isolation of the precipitate by means of a mechanical separation process and mixing the preformed mixed oxide Bi1WbOx with a precursor having the stoichiometry [Mo12Z1cZ2dFeeZ3fZ4gZ5hOy], shaping the mixture to form shaped bodies and thermally treating and calcining the shaped bodies at elevated temperature to give the shaped catalyst bodies. The process leads to homogeneous precipitation products having a stoichiometric composition. It is an alternative to the energy-intensive production by spray drying.

主权项

1: A process for producing a shaped catalyst body comprising a multi-element oxide formula I as an active composition,
[Bi1WbOx]a[Mo12Z1cZ2dFeeZ3fZ4gZ5hOy]1  (I), wherein Z1 is at least one element selected from the group consisting of nickel and cobalt, Z2 is at least one element selected from the group consisting of alkali metals and alkaline earth metals, Z3 is at least one element selected from the group consisting of zinc, phosphorus, arsenic, boron, antimony, tin, cerium, vanadium, chromium and bismuth, Z4 is at least one element selected from the group consisting of silicon, aluminum, titanium, tungsten and zirconium, Z5 is at least one element from the group consisting of copper, silver, gold, yttrium, lanthanum and the lanthanides, a=0.1 to 3, b=0.1 to 10, c=1 to 10, d=0.01 to 2, e=0.01 to 5, f=0 to 5, g=0 to 10, h=0 to 1, and x and y represent numbers which are determined by the valence and abundance of the elements other than oxygen in formula I, wherein the process comprises: preforming a mixed oxide Bi1WbOx, wherein the preformation of the mixed oxide Bi1WbOx comprises coprecipitation from an aqueous environment at a pH in the range from 1.5 to 3 to obtain a precipitate; and isolating the precipitate by a mechanical separation process.