The Underlying Mechanism of Hydrothermal Stability for Ordered Mesoporous Molecular Sieves without Micropores

Micropore-free SBA-15-type mesoporous molecular sieves MSAMS-2 and MSAMS-4 show extraordinary stability both in boiling water (100 °C over 360 h) and high temperature steam (800 °C for 6 h). FT-IR together with XRD, FE-SEM and HR-TEM characterizations demonstrate the zeolite-like five-membered ring subunits other than zeolite crystals embedded within the framework pores of MSAMA-2 and MSAMS-4 should play a crucial role in improving the hydrothermal stability.