P. Kripylo et al., THE MUTUAL PROMOTION EFFECT OF MOLYBDATES IN MULTICOMPONENT MOLYBDATECATALYSTS, Journal fur praktische Chemie, Chemiker-Zeitung, 335(8), 1993, pp. 699-704
Multicomponent molybdate catalysts (e.g. of the composition Bi2Fe1,5Co
7Cr10Mo19Oy) are produced by coprecipitation, drying and calcination.
These catalysts exhibit high activity and selectivity in the ammoxidat
ion of propene to acrylonitrile. The individual molybdates (Co-, Fe- a
nd Cr-molybdate) exhibit no selectivity in the ammoxidation of propene
. Therefore a mutual promotion effect of these molybdates exists. The
cause of the promotion effect is the formation of the active and selec
tive phase from the beta-phase of Co-molybdate by exchange of protons
with ions of Fe3+ and Cr3+ from the molybdates of Fe and Cr. The struc
ture of this catalytic active and selective phase is similar to the st
ructure of the beta-phase of Co-molybdate.