The application discloses a preparation method of a
molecular sieve catalyst, comprising: obtaining a ZSM-5
seed crystal gel solution; adding a mixture I containing
silicon source, aluminum source, alkali and water to the ZSM-5
seed crystal gel In the solution, the mixture is obtained, aged, and a
solid gel is obtained; under sealed conditions, the
solid gel is steam-assisted crystallized, roasted,
ammonium ion exchanged, and roasted to obtain a nano ZSM-5
molecular sieve; the obtained nano The ZSM‑5
molecular sieve is treated with steam, modified with
phosphorus, and calcined to obtain the molecular
sieve catalyst. The catalyst of the present application has the characteristics of uniform acid site distribution and high
crystallinity, and the preparation process produces less waste water, which is convenient for scale-up production; the catalyst has good hydrothermal stability in the
alkylation reaction of
ethanol and
benzene, and can be used at a lower
benzene-
alcohol ratio The high ethyl selectivity can still be maintained under the feed conditions, and the
xylene impurity content in the product is low, so it has good industrial application prospect.