METHOD FOR PREPARING MESOPOROUS CRYSTALLINE MOLECULAR SIEVE

摘要

PURPOSE: An improved method for preparing mesoporous crystalline molecular sieve having large pore size and superior hydrothermal stability is provided. CONSTITUTION: The method for preparing mesoporous crystalline molecular sieve comprises the steps of a) preparing a first solution by dissolving 2 to 20 weight parts of silica alone or a mixture of silica and a metal salt or metal alkoxide into 100 weight parts of a hydrogen fluoride solution having concentration of 5 to 50%, wherein a mole ratio of Si/metal is 10 or more; b) preparing a second solution by dissolving 2 to 12 weight parts of cationic surfactant into 100 weight parts of distilled water; c) uniformly mixing the solutions by adding the first solution to the second solution in a weight ratio of 1 to 2:1 (second solution/first solution), and preparing powder by filtering and drying the aged solution after aging the resulting solution at a temperature of 25 to 80 deg.C for 10 to 18 hours by adding 20 to 30 weight parts of concentrated aqueous ammonia (based on 100 weight parts of the hydrogen fluoride solution) to the mixed solution; and d) adding the powder to 200 to 300 weight parts (based on 100 weight parts of the hydrogen fluoride solution) of an ethanol acidic solution, and calcining the resulting material at a temperature of 300 to 600 deg.C for 2 to 4 hours.