New Understanding and Simple Approach to Synthesize Highly Hydrothermally Stable and Ordered Mesoporous Materials

Abstract

Highly ordered mesoporous materials with extremely high hydrothermal stability have been successfully synthesized by a novel and facile approach. Our method is built on the understanding that the hydrothermal treatment process plays an important role in the synthesis of mesoporous materials. It is proposed that in order to use high temperature hydrothermal treatment to increase the inorganic framework cross-linkage, an important requirement is that the organic surfactants must be retained as much as possible to maintain the preformed organic−inorganic composite mesostructure against framework shrinkage during the hydrothermal treatment process. This requirement can be achieved by enhancing the surfactant−silanol interaction at the organic−inorganic interface through adjusting the hydrothermal treatment pH and adding acetic acid (HAc) during the synthesis. When a high temperature (∼200 °C) hydrothermal treatment is employed, ordered mesoporous materials can only be obtained in a hydrothermal treatment pH r...