New Strategy to Synthesis of Hierarchical Mesoporous Zeolites

We report a new strategy to synthesize the hierarchical mesoporous zeolite through design of mesoscale cationic surfactant cetyltrimethylammonium bromide (CTAB) micelle with cosolvent tert-butyl alcohol (TBA) and the 1,3,5-trimethylbenzene (TMB) additive, by which the formation of hierarchical mesostructure arose from the condensing of zeolite fragments on the mesoscale surfactant micelles. The hierarchical mesoporous silica with zeolite Y or sodalite fragment is synthesized for the first time, which exhibited both the mesostructure and the typical diffraction of zeolite. XRD, N2 adsorption−desorption, 27Al MAS NMR, FTIR, and NH3-TPD techniques were employed to characterize the resulting samples, and the adsorption of NPYR (N-nitrosopyrrolidine) and NNN (N-nitrosonornicotine) were performed to assess the adsorptive capability of the zeolitic mesoporous materials. The MS3-4t-5b sample synthesized by assembling zeolite gel exhibited the adsorptive capacity comparable to NaY zeolite for trapping NPYR in airflow but four times superior to NaY for adsorbing bulky nitrosamine NNN in solution because of its hierarchical mesostructure.