The invention discloses a method for preparing a multistage-hole ZSM-5
molecular sieve, and belongs to the technical field of synthesis of molecular sieves. The invention provides the preparation method of the multistage-hole ZSM-5
molecular sieve which is low in cost and low in
pollution, can change a
silicon aluminum ratio (30-100) to the
molecular sieve in a wide range, and has a large mesoporous volume. The method comprises the following steps of I, preparing
crystal seeds for the synthesis of the multistage-hole ZSM-5 molecular
sieve; II, preparing mixed gel, and performing stirring at
room temperature; III, adding the
crystal seeds prepared in the step I into the gel obtained in the step II, performing low-temperature
crystallization for a short time, and adding a little organic
silicon; and IV, continuing
crystallization, performing cooling, performing
centrifugal filtration, performing washing, performing
drying, and performing
roasting so as to obtain the multistage-hole ZSM-5 molecular
sieve. According to the method provided by the invention, a few organic amine template agents are used only in the
crystal seed synthesizing process, an s small, so that d besides, the addition amount of the added organic
silicon as a mesoporous hole forming agent i compared with a method for synthesizing other multistage-hole ZSM-5 molecular
sieve, the method disclosed by the invention has the advantages that the dosage of the template agents is small, products have a large mesoporous volume, and the problems that the production cost of the molecular sieve is high and environment is polluted caused by the condition that the organic template agent is high in price and large in
toxicity can be solved.