MCM-48介孔分子筛的高压合成

采用正硅酸乙酯（TEOS）作硅源，十六烷基三甲基溴化铵（CTAB）为模板剂，在高压 （约7 MPa）和373 K下合成了MCM-48介孔分子筛.用XRD、氮气吸附及29Si MAS NMR对样品 进行了表征.与常压合成的相比，高压下合成的MCM-48具有更高的热稳定性和水热稳定性.2 9Si MAS NMR结果表明，高压有利于分子筛孔壁的聚合，导致分子筛结构更加完善，从而使 其具有更高的稳定性.

Synthesis of MCM-48 under High Pressure

MCM-48 was synthesized with tetraethylorthosilicate (TEOS) as silica source and cetyltrimethylammonium bromide (CTAB) as template at high pressure (ca.7 MPa) and 373 K. The synthesized compounds were characterized using different analytical techniques such as X-ray diffraction,N2 adsorption and desorption measurement,and ~(29)Si MAS NMR.MCM-48 synthesized at high pressure appeared higher thermal and hydrothermal stability than that synthesized at autogenous pressure.The ~(29)Si MAS NMR results demonstrated that high pressure promoted the wall polymerization and leaded to a high quality MCM-48.MCM-48 was also synthesized with such a low ratio of CTAB/Si as 0.16,but that synthesized with high ratio of CTAB/Si was more stable.