Enhancement of thermal and hydrothermal stability of MCM-41 by TiO 2 deposition

Abstract

TiO2 was deposited onto the mesoporous surface of siliceous MCM-41 by chemical liquid deposition. The deposition of TiO2 on MCM-41 was found to largely enhance the thermal stability of mesoporous framework, and the calcination treatment at 1173 K remarkably improved the hydrothermal stability of mesostructure of TiO2/MCM-41. The fraction of anatase phase to rutile phase on TiO2/MCM-41 was controllable through varying heating rate, and the thermal treatment using a fast heating rate of 65 °C/min benefited the growth of rutile phase. The lower TiO 2 loading ≤19.7-wt% was beneficial to the formation of TiO 2/MCM-41 with a high BET surface area of >900 m2/g; however, the higher TiO2 loading up to 45.2 wt% led to an abrupt drop of BET surface area of the resulting material to 544 m2/g due to the partial blockage of mesopores.