The invention relates to a preparation method of a multilevel pore
heteroatom MFI-type
molecular sieve. The preparation method comprises the following steps: S1, preparing xerogel; S2, performing
sulfuric acid pre-
carbonization for the xerogel; S3, carbonizing the xerogel at a high temperature to obtain C-SiO2 complex; S4, uniformly mixing a compound containing
heteroatom, a micropore template agent, an alkaline source and deionized water, adding the C-SiO2 complex, sufficiently mixing, crystallizing, washing,
drying,
roasting, and obtaining the multilevel pore
heteroatom MFI-type
molecular sieve. The multilevel pore heteroatom MFI-type
molecular sieve has the advantages that (1) compounds such as tween, span or triton are used as a
mesoporous carbon source, so that the synthetic cost is decreased; and (2) the xerogel is subjected to the
sulfuric acid pre-
carbonization and high-temperature
carbonization to obtain the C-SiO2 complex sufficiently coated with a
silicon source and carbon material, the heteroatom is easier to anticipate in the
crystallization of the molecular
sieve in the liquid-phase
mechanical drive process in an
ion form, the amount of the heteroatom entering a molecular
sieve skeleton is increased, the catalytic activity is improved, the dispersion limitation of intrinsic micropores of
zeolite on the catalytic reaction is effectively solved, and the application in the field of macromolecular
catalysis is enlarged.