New Routes to the Synthesis of Mesoporous Materials and Their Properties |
| |
Authors: | SUN Yan LIN Wen-yong HUO Qi-aheng PANG Wen-qin YUE Yong |
| |
Institution: | 1. Department of Chemistry, Jilin University, Changchun, 130023;
2. Wuhan Institute of Physics, Academia Sinica, Wuhan, 430071 |
| |
Abstract: | The factors that influence the hydrothermal synthesis of MCM-41 were investigated, and it was found that compared with those from high H2O/SiO2 systems(designated MCM-41-A), the products from low H2O/SiO2 systems(designated MCM-41-B) exhibited a less-defined X-ray powder diffraction (XRD) pattern with a broader main reflection peak at a lower 2θ diffraction angle. MCM-41-B possesses a smaller surface area but a larger pore size than MCM-41-A. New routes including direct thermal treatment, room-temperature crystallization and microwave heating were developed for the formation of MCM-41, and the properties of the products prepared from these new routes were compared with those of the MCM-41 hydrothermally synthesized. The pore sizes of MCM-41 materials are uniformly distributed with an effective pore diameter that falls into the range of 2-4 nm, where as the products from wet-gel thermal treatment possess two kinds of mesopores:the well-defined smaller pores distributed at 3 nm and the larger one within 8-20 nm. The MAS NMR spectroscopy revealed that after calcination to remove the organic template in Al-containing MCM-41, a small part of the tetrahedrally-coordinated framework aluminum atoms became octahedrally-coordinated and a considerable amount of Si-OH species were generated. |
| |
Keywords: | Mesoporous molecular sieves Hydrothermal synthesis Thermal treatment Room-temperature crystallization Microwave heating |
|
| 点击此处可从《高等学校化学研究》浏览原始摘要信息 |
| 点击此处可从《高等学校化学研究》下载免费的PDF全文 |
|