View article

Highly ordered hexagonal mesoporous aluminosilicates (MAS-5) with uniform pore sizes have been successfully synthesized from assembly of preformed aluminosilcate precursors with cetyltrimethylammonium bromide (CTAB) surfactant. The aluminosilicate precursors were obtained by heating, at 100−140 °C for 2−10 h, aluminasilica gels at the Al₂O₃/SiO₂/TEAOH/H₂O molar ratios of 1.0/7.0−350/10.0−33.0/500−2000. Mesoporous MAS-5 shows extraordinary stability both in boiling water (over 300 h) and in steam (800 °C for 2 h). Temperature-programmed desorption of ammonia shows that the acidic strength of MAS-5 is much higher than that of MCM-41 and is comparable to that of microporous Beta zeolite. In catalytic cracking of 1,3,5-triisopropylbenzene and alkylation of isobutane with butene, MAS-5 exhibits greater catalytic activity and selectivity, as compared with MCM-41 and HZSM-5. The MAS-5 …