【摘要】 采用低温晶化法一步合成了纳米硅铝介孔分子筛(记为Z-1),并通过XRD、BET、N2吸/脱附曲线和TEM等手段对其结构性质进行了表征.结果表明:所合成的分子筛具有类似MCM-41的六方结构,较好的介孔特征,孔分布狭窄,纳米级晶粒(40～50nm).用氨气程序升温脱附(NH3-TPD)法测试了其酸强度;并采用脉冲法,以异丙苯和1,3,5-三异丙苯的催化裂化为探针反应,考察了该分子筛的催化裂化性能和水热稳定性.Z-1与后嫁接法制得的AlMCM-41相比,呈现出较高的催化活性、选择性和蒸气稳定性.更多还原

【Abstract】 Mesoporous aluminosilicate (denoted as Z-1) nanoparticles were synth esized from assembly of mixture of tetraethylorthosilicate (TEOS) and aluminum n itrate nonahydrate (ANN) with cetyltrimethylammonium bromide (CTAB) as template at low temperture.Important informations about textural properties of the materi al were obtained by powder X-ray diffraction (XRD), N2 adsorption-desorption i sotherms at 77 K and transmission electron microscopy (TEM),and the acid propert ies were determined by temperture-programmed desorption of ammonia (NH3-TPD).T he results obtainted by these methods indicated that the material possessed hexa gonal mesostructure,narrow pore-size distribution and nanoparticles.The NH3-TP D showed that the acdity strength of Z-1 was similar to AlMCM-41,but the amoun t of medium-acid of Z-1 was more than that of AlMCM-41 prepared by post-synt hesis method.In catalytic cracking of cumene and 1,3,5-triisopropylbenzene,Z-1 exhibited higher cataclytic acitivity,selectivity and steam stability (100% w ater vapor,800 ℃,2 h) compared with AlMCM-41.更多还原