Process for production of metal oxide-antimony oxide catalysts

Abstract

Abstract This invention provides an improved process for producing a metal oxide-antimony oxide catalyst, which comprises the steps of (a) heat treating an intimate mixture of the catalyst ingredients at a temperature of 200*-600* C. in the presence of a reducing gas or vapor having an electron donor character, said gas or vapor being present in an amount sufficient to make up a reducing atmosphere, (b) precalcining the resulting product at a temperature of 300*-600* C. in an oxidative atmosphere, and (c) calcining the precalcined product at a temperature of 800*1,000* C. in an oxidative atmosphere. A precalcination and a final calcination similar to the steps (b) and (c), per se, are known; but the step (a) and the combination of steps (a), (b) and (c) are novel. The catalysts prepared by the present process are useful for oxidation and ammoxidation of olefins, and they exhibit an improved activity and an improved selectivity with respect to the objective product. For example, iron (uranium or tin) oxide-antimony oxide catalyst supported on silica is prepared according to the present process wherein the step (a) is carried out by using NH3 (H2 or C3H3) with or without a diluent (N2, etc.) at 350*-400* C., and the step (b) and (c) are carried out in an airstream at 400*-550* C. and at 900*-950* C., respectively. The resulting catalyst is used for ammoxidation of propylene to acrylonitrile, and it exhibits improved conversion of propylene to acrylonitrile ( about 71 percent) compared with the corresponding control catalyst not subjected to the step (a) treatment ( about 66 percent).

Inventors

• 👤 Takachika Yoshino
• 👤 Shigeru Saito
• 👤 Masukuni Sobukawa
• 👤 Tadao Shizokuishi

Bibliographic Details