Abstract
•ZSM-2 nanorods with crystal size about 50nm were synthesized at 30 °C.•The samples synthesized at 30 °C and 100 °C showed different characteristics.•The crystallization process of ambient synthesis was discussed.
ZSM-2 nanorods with crystal size around 50nm were successfully synthesized at ambient temperature (30°C). The crystallization process of ZSM-2 zeolite under ambient temperature was studied and discussed according to the measurement of crystallization kinetic curve, and characterizations with multiple techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), low-temperature N2 adsorption/desorption analysis, thermogravimetry analysis (TG) and nuclear magnetic resonance (NMR) etc. The ZSM-2 zeolite synthesized at ambient temperature presented different crystal morphologies and large specific area as compared with the sample synthesized at high temperature (100°C). Furthermore, 29Si MAS-NMR showed that the nanoscale ZSM-2 obtained by ambient synthesis contained more EMT phase and lower Si/Al ratio than that of micrometer-sized ZSM-2 crystals obtained at 100°C. More interestingly, NMR and low-temperature N2 adsorption/desorption characterizations revealed that the local environment of Al did not change much while that of Si did change a lot during the ambient crystallization process, and the micropore area increased rapidly while the micropore size distributions of the samples changed little with increasing crystallization time.