摘要 |
An oxidation catalyst wherein the catalytically active component has the general formula Mo12PaRhbCucVdCseXfYgZhOx, where X is Cr and/or Fe, Y is Nb, Z is Na, Li, K and/or Rb, a is 0.1-4, b is 0.001-1, c is 0.05-2, d is 0.05-4, e is 0.1-5, f is 0-2, g is 0-3 and h is 0-2, and x is the number of oxygen atoms required to saturate the valencies of the other constituents, is very suitable for the preparation of methacrylic acid by gas phase oxidation of methacrolein with an oxygen-containing and steam-containing gas mixture.
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