Claims
- 1. A process for preparing methacrylic acid comprising oxidizing methacrylein by a catalytic gas-phase oxidation in the presence of a catalyst of the formula I
- Mo.sub.12 P.sub.a V.sub.b X.sub.c.sup.1 X.sub.d.sup.2 C.sub.e.sup.3 Sb.sub.f Re.sub.g S.sub.h O.sub.n (I),
- where
- X.sup.1 is potassium, rubidium and/or cesium,
- X.sup.2 is copper and/or silver,
- X.sup.3 is cerium, boron, zirconium, manganese and/or bismuth,
- a is from 0.5 to 3.0,
- b is from 0.01 to 3.0,
- c is from 0.2 to 3.0,
- d is from 0.01 to 2.0,
- e is from 0 to 2.0,
- f is from 0.01 to 2.0,
- g is from 0 to 1.0,
- h is from 0.001 to 0.5 and
- n is a number determined by the valency and the content of the elements different from oxygen in I.
- 2. A process as claimed in claim 1, where h in formula I is from 0.03 to 05.
- 3. A process as claimed in claim 1, where g in formula I is from 0.04 to 1.
- 4. A process as claimed in claim 1, where h in formula I is from 0.03 to 0.5 and g is from 0.04 to 1.
Priority Claims (1)
Number |
Date |
Country |
Kind |
4022212 |
Jul 1990 |
DEX |
|
Parent Case Info
This is a division of application Ser. No. 07/729,169, filed on Jul. 12, 1991.
Foreign Referenced Citations (3)
Number |
Date |
Country |
51348 |
May 1982 |
EPX |
102688 |
Mar 1984 |
EPX |
265733 |
May 1988 |
EPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
729169 |
Jul 1991 |
|