Thermal stability of mesoporous silica molecular sieve

Abstract

Mesoporous silica molecular sieves (MCM-41) with pore diameters from 3 to 10 nm were synthesized by a liquid-crystal template mechanism. A surface phonon mode at around 961 cm-1, connected with the mesoporous structure was observed. At the annealing temperature of 800 °C, the mesoporous structure of the molecular sieve was found to collapse completely, based on Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) measurements. Further annealing of MCM-41 results in transformation to the cristobalite phase of silica.