Patent ID: 7772148

Claim:
A catalyst comprising a metal oxide of the general formula I, Mo 12 W a Co b Fe c Bi d Si e K f O n (I) where a=from ≧1 to ≦3, b=from ≧3 to ≦8, c=from ≧1 to ≦4, d=from ≧0.5 to ≦1.5, e=from ≧0 to ≦10, f=from ≧0 to ≦0.2 and n=a number which is determined by the valency and frequency of the elements in the composition of formula I other than oxygen, wherein a ratio of Co/Fe is from 2 to 3.5, a ratio of Co/Mo is from 0.55 to 0.7, the catalyst is annular in shape, and the catalyst is unsupported.