Patent ID: 6867328

Claim:
A process comprising contacting a gaseous mixture comprising propane and oxygen with a catalyst to heterogeneously catalyze the oxidation of propane to acrylic acid, wherein the catalyst is at least one multimetal oxide material having stoichiometry I, Mo 1 V b M c 1 M d 2 O n (I), where M 1 is Te, Sb, or both Sb and Te, M 2 is at least one element selected from the group consisting of Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Go, Rh, Ni, Pd, Pt, La, Bi, B, Ce, Sn, Zn, Si and In, b is from 0.01 to 1, c is from >0 to 1, d is from >0 to 1 and n is a number which is determined by the valency and frequency of the elements other than oxygen in (I), wherein the X-ray diffraction pattern of the multimetal oxide material has reflections h, i and k whose peaks are at the diffraction angles (2θ): 22.2±0.4° (h), 27.3±0.4° (i) and 28.2±0.4° (k), the reflection h is the most intense reflection within the X-ray diffraction pattern and has a half-width of not more than 0.5°, the intensity P 1 of the reflection i and the intensity P k of the reflection k satisfy the relationship 0.65≦R≦0.85, where R is the intensity ratio defined by the formula R=P i /( P i +P k ) and the half-width of the reflection i and the reflection k each are ≦1°, wherein the at least one multimetal oxide material (I) has an X-ray diffraction pattern having no reflection with the peak position (2θ): 50.0±0.3°.