Multilayered shell catalysts for catalytic gaseous phase oxidation of aromatic hydrocarbons
AssigneeBASF SE
InventorsThomas Heidemann, Stefan Bauer, Gerd Linden, Hermann Petersen
Life of this patent
Estimating the term…
Loading patent…
AssigneeBASF SE
InventorsThomas Heidemann, Stefan Bauer, Gerd Linden, Hermann Petersen
Estimating the term…
A coated catalyst for the catalytic gas-phase oxidation of aromatic hydrocarbons comprises, on an inert nonporous support, a catalytically active composition comprising a defined amount of vanadium oxide, titanium dioxide, a cesium compound, a phosphorus compound, and antimony oxide, wherein the catalytically active composition is applied in two or more layers and where relative to the inner layer or inner layers the outer layer has an antimony oxide content which is from 50 to 100% lower and wherein the amount of catalytically active composition of the inner layer or layers is from 10 to 90% by weight of the amount of catalytically active composition, and can be used for preparing carboxylic acids and/or anhydrides, in particular phthalic anhydride; also specified is a production process for such catalysts.
A coated catalyst for the catalytic gas-phase oxidation of aromatic hydrocarbons, comprising, on an inert nonporous support, a catalytically active composition comprising, in each case based on the total amount of catalytically active composition, from 1 to 40% by weight of vanadium oxide, calculated as V2O5, from 60 to 99% by weight of titanium dioxide, calculated as TiO2, up to 1% by weight of a cesium compound, calculated as Cs, up to 1% by weight of a phosphorus compound, calculated as P, and a total of from more than 0 up to 10% by weight of antimony oxide, calculated as Sb2O3, wherein the catalytically active composition is applied in two or more layers, where the inner layer or inner layers have an antimony oxide content of from 1 to 15% by weight and the outer layer has, in contrast, an antimony oxide content which is from 50 to 100% lower, the amount of catalytically active composition of the inner layer or the inner layers is from 10 to 90% by weight of the total amount of catalytically active composition and the amounts of the constituents of the catalytically active composition are to be selected from the stated ranges such that they sum to 100% by weight.
Dependencies are inferred from the claim text.