Silicon-containing molecular sieve and preparation method thereof

Abstract

The invention relates to the field of catalysis and in particular provides a silicon-containing molecular sieve and a preparation method thereof. The preparation method comprises the following steps:(1) hydrolyzing a silicon source, a VIII family metal source and a structure directing agent to obtain a hydrolyzed material; and (2) crystallizing the hydrolyzed material, wherein the step (1) is carried out in presence of an organic phosphorus compound and / or before the step (2), the hydrolyzed material is mixed with the organic phosphorus compound, then the crystallization is carried out, and the VIII family metal source is an iron source or a mixture of an iron source and a cobalt source. The silicon-containing molecular sieve prepared by adopting the preparation method can be applied to various fields such as dehydration reaction, selective dehydrogenation reaction, alkylation reaction, denitration reaction (reduction) and isomerization reaction. When the silicon-containing molecularsieve is applied to cyclohexyl hydroperoxide catalytic decomposition, an extra alkaline reagent does not need to be added, and reaction effects such as high alcohol ketone ratio and high alcohol ketone selectivity can be obtained at relatively low temperature.

Description

technical field [0001] The invention relates to a silicon-containing molecular sieve and a preparation method thereof. Background technique [0002] Cyclohexanone is an important basic chemical raw material, which has been used in the production of important chemical products such as caprolactam, adipic acid and ε-caprolactone. According to statistics, by the end of 2015, the production capacity of cyclohexanone in my country had reached 3.65 million tons. In my country, cyclohexanone is mainly produced through cyclohexane oxidation and cyclohexene hydration processes, and the production capacity of cyclohexane oxidation accounts for as high as 63%. [0003] The existing cyclohexane oxidation process mainly includes three processes: cyclohexane oxidation, cyclohexyl hydroperoxide decomposition and cyclohexanol dehydrogenation. Although the cyclohexanol dehydrogenation process is relatively mature and stable, there are many side reactions in the cyclohexane oxidation proces...

AI Technical Summary

Problems solved by technology

[0006] Although the above, the interaction between metal oxide and carrier is weak, the stability of the supported catalytic material needs to be improved; in the supported catalyst, the content of metal oxide is high (>1% mass fraction), which is difficult to ensure the active component can be evenly distributed; the pore size of the AFI and MFI structures is not greater than 0.55nm, while the molecular size of cyclohexyl hydroperoxide is about 0.74nm, the Cr active center in the two molecular sieves is difficult to interact with CHHP, and the active center of the heteroatom molecular sieve The effective utilization rate is low; although the mesoporous TUD has a large pore structure, its pore wall is an amorphous species, and its hydrothermal stability is not ideal

Images