Synthesis of hydrothermally stable MCM-48 mesoporous molecular sieve at low cost of CTAB surfactant

Abstract

The hydrothermally stable MCM-48 mesoporous molecular sieve was successfully prepared at extremely low cost of cetyltrimethylammonium bromide (CTAB) by carefully adjusting the synthesis conditions. The increasing of the crystallization temperature from 373 K to 423 K can dramatically reduce the CTAB surfactant amount for the preparation of MCM-48 from 0.65 to 0.1 of the CTAB/Si ratio. The effect of increasing crystallization temperature on the formation process of MCM-48 at low CTAB cost was carefully studied. The influences of OH −/Si ratio and fluoride addition to the structure stability of the MCM-48 material synthesized at CTAB/Si = 0.1 and 423 K were systematically studied by XRD patterns. Moreover, the combination of increasing crystallization temperature and adding small amount of fluoride ions can considerably improve the structure stability of MCM-48 when reducing the CTAB cost.