关键词: 伯胺, 模板剂, 分子筛, 结构表征, 稳定性, 铁化合物

We synthesized and characterized Fe-containing hexagonal mesoporous silica (FeHMS) molecular sieves by means of some modern physico- chemiscal techniques (XRD, SEM, TEM, BET, TG/DTA, FT-IR, EPR, Mossbauer spectroscopy, etc.), together with NH~3-TPD. We found more iron still retain in the framework after removal of the surfactant. The particle of FeHMS is smaller than that of SiHMS, and its surface is smoother. The pore size distribution of FeHMS reveals that there are two type mesopores, with diameters being 2.5nm and 10nm, respectively. It is found that Fe is mainly in the tetrahedral coordinated framework in as-synthesized samples. After removal of the template by calcination, a part of Fe transfers to the wall surface. In case of using acidified alcohol to extract surfactant, it is more effective to retain Fe in tetrahedral coordinated framework. Fe species on wall surface are of high dispersion when removing the surfactant at high temperature. The results indicate that the introduction of Fe could improve the hydrothermal stability. It seems that the octahedral Fe(III) species is responsible for the above improvement. Owing to the thicker wall, FeHMS appears to possess better thermal and hydrothermal stability than FeMCM-41.

Key words: PRIMARY AMINE, TEMPLATE AGENT, MOLECULAR SIEVE, STRUCTURE CHARACTERISTICS, STABILITY, IRON COMPOUNDS