Catalyst for selectively oxidizing tertiary butanol or isobutene to synthesize methyl acrylic aldehyde and its use

Abstract

The present invention provides a kind of catalyst for selectively oxidizing tertiary butanol or isobutene to synthesize methyl acrolein and its preparation process and application in gas phase catalytic oxidizing synthesis of methyl acrolein. The catalyst of the present invention is one kind of composite oxide containing Mo, Bi, Fe, Co, Sb, Pb, Yb, etc. and has high catalytic activity and stability, long service life, isobutene converting rate higher than 95 % and methyl acrolein selectivity over 86 % in the presence of molecular oxygen.

Description

technical field [0001] The invention relates to the preparation of a multi-component composite oxide catalyst for synthesizing methacrolein (MAL) by using tert-butanol or isobutene as raw material through selective oxidation and its application in the selective oxidation reaction of tert-butanol or isobutene. Background technique [0002] Methyl methacrylate (MMA) is widely used in the fields of national defense, construction and fine chemicals, such as the production of plexiglass, plastic modifiers, advanced environmental protection coatings and adhesives. Although the traditional method of producing MMA—the acetone cyanohydrin method has a mature process, the raw materials are highly toxic and acidic, and the amount of three wastes produced is large, which not only poisons the human body, severely corrodes equipment and seriously pollutes the environment, but also has poor atom economy. In recent years, countries all over the world have carried out the research and develo...

AI Technical Summary

Problems solved by technology

[0004] Since the preparation of MAL by oxidation of isobutene or tert-butanol is a strong exothermic reaction, it is easy to generate local overheating in the catalyst bed, resulting in the loss of the most important oxidation active component Mo during the reaction process, thereby shortening the service life of the catalyst. In the patent In CN1143946A and CN1467032A, cerium (Ce), a component with heat resistance and reduction resistance, is used to suppress the loss of Mo and achieve the purpose of prolonging the life of the catalyst, but the addition of Ce has caused the reduction of methacrolein selectivity; And other patents such as CN1048540A and Japanese Patent No. 10614 propose to dilute the catalyst with an inert substance to improve the thermal conductivity of the catalyst. Patents CN1099024 and CN1042200 propose that by adding MoO 3 To compensate the loss of molybdenum in the catalyst, although these methods alleviate the serious loss of molybdenum to a certain extent, they all reduce the activity or selectivity of the catalyst, and cannot guarantee the performance degradation of the catalyst in long-term operation.

Elements such as tellurium (Te) and thallium (Tl) are used as the key components of the catalyst in patent US4250339, Japanese publication patent 57-72937 and CN1131059A, to improve the activity and selectivity of the catalyst, but these substances themselves run in the catalyst for a long period of time It is easy to lose in the medium, and the result will also cause the performance of the catalyst to deteriorate during use

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