Synthesis of mesoporous aluminosilicate nanoparticles and its performance in catalytic cracking

Mesoporous aluminosilicate (denoted as Z-1) nanoparticles were synthesized from assembly of mixture of tetraethylorthosilicate (TEOS) and aluminum nitrate nonahydrate (ANN) with cetyltrimethylammonium bromide (CTAB) as template at low temperture. Important informations about textural properties of the material were obtained by powder X-ray diffraction (XRD), N₂ adsorption-desorption isotherms at 77 K and transmission electron microscopy (TEM), and the acid properties were determined by temperture-programmed desorption of ammonia (NH₃-TPD). The results obtainted by these methods indicated that the material possessed hexagonal mesostructure, narrow pore-size distribution and nanoparticles. The NH₃-TPD showed that the acdity strength of Z-1 was similar to A1MCM-41, but the amount of medium-acid of Z-1 was more than that of A1MCM-41 prepared by post-synthesis method. In catalytic cracking of cumene and 1, 3, 5-triisopropylbenzene, Z-1 exhibited higher cataclytic acitivity, selectivity and steam stability (100% water vapor, 800°C, 2 h) compared with A1MCM-41.