New silica-supported vanadium oxide-based catalyst

摘要

A new vanadium oxide-based oxidation catalyst (I) comprises: (a) 5-30 wt.% of one or more vanadium compounds of formula (II); and (b) 70-95 wt.% of a carrier of BET specific surface 1-50 m2/g, consisting of 90-100 wt.% silica and 0-10 wt.% aluminia and/or zirconia. MxV6O15 (II) M = Li, Na, K, Rb, Cs, Mg and/or Ca; and x = 0-1. Also claimed are: (i) the preparation of a vanadium oxide-based oxidation catalyst (I'), by applying vanadium pentoxide or ammonium vanadate (and optionally one or more of the oxides, hydroxides, carbonates, vanadates and organic acid salts of M, such that the M:V atomic ratio is 0-1:6 (preferably 1:6)) to an amorphous carrier containing 90-100 wt.% silica and 0-10 wt.% aluminia and/or zirconia, then calcining at 400-800 deg C; (ii) (I') obtained by process (i); (iii) the use of (I) or (I') as catalyst for the gas-phase oxidation of alkyl groups on an aromatic or heteroaromatic ring system to carboxy groups; and (iv) the use of (II; M = Li, Na, K, Rb or Cs; x = 0. 8-1) (optionally on a carrier), as catalyst for the gas-phase oxidation of alkyl groups on a heteroaromatic ring system to carboxy groups.