Method for synthesizing monodisperse MCM-41 molecular sieves with two particle size distribution ranges by one-step process

Abstract

The invention discloses a method for synthesizing monodisperse MCM-41 molecular sieves with two particle size distribution ranges by a one-step process, which comprises the following steps: (1) dissolving a template CTAB (cetyltrimethylammonium bromide) in a polyvinyl alcohol water solution-ethanol mixture system, and adding ammonia water; stirring, dropwisely adding ethyl silicate, and stirring to obtain a white milky suspension; (2) centrifuging at a low rotation speed to remove deposit slag, centrifuging the centrifugate at the rotation speed of 4000-5000 r / min to obtain first template-bearing molecular sieve particles and a centrifugate, and centrifuging the centrifugate at the rotation speed of 10000-12000 r / min to obtain second template-bearing molecular sieve particles and a centrifugate; and (3) respectively drying and calcining the two template-bearing molecular sieve particles to obtain the MCM-41 molecular sieves respectively with the particle size ranges of 400-700nm and 100-300nm. The method disclosed by the invention is simple and consumes shorter time in the synthetic process; and the molecular sieve particles have the advantages of regular shape and favorable dispersity.

Description

technical field [0001] The invention relates to a method for synthesizing MCM-41 molecular sieves with two particle size distributions in one step, and belongs to the technical field of inorganic functional materials. Background technique [0002] In 1992, the Mobil Petroleum Company of the United States first launched the M41S series of new mesoporous materials, among which MCM-41 attracted the most attention. MCM-41 has excellent characteristics such as uniform and adjustable pore size, large specific surface area, strong adsorption capacity, etc., and its surface is easily modified with inorganic or organic groups, which makes it suitable for catalysis, ion exchange, adsorption separation and higher Inorganic materials and other fields have a wide range of application value and academic research value. [0003] At present, researchers have carried out a lot of exploration work on the synthesis of MCM-41. MCM-41 molecular sieves with different characteristics were obtain...

AI Technical Summary

Problems solved by technology

However, the synthesized MCM-41 mesoporous molecular sieves are often agglomerated severely, which makes it impossible to better disperse in the use system during use, thereby reducing the use efficiency

In addition, molecular sieves are irregular in shape and non-uniform in size, which makes thermal conduction uneven when molecular sieves are used as host materials, and energy transfer is also uneven during the electron transition process of the carried guest materials.