A crystal seeds-assisted synthesis of microporous and mesoporous silicalite-1 and their CO2/N-2/CH4/C2H6 adsorption properties

作者：Wang, Chang; Liu, Jiaqi; Yang, Jiangfeng^*; Li, Jinping

来源：Microporous and Mesoporous Materials, 2017, 242: 231-237.

DOI：10.1016/j.micromeso.2017.01.029

• Zeolite
• Crystal seeds
• Microporous and mesoporous
• Adsorption
• Adsorption selectivity

Synthesis of ultra-high silica (SiO2/Al2O3 > 1800) MFI type zeolite such as silicalite-1 is still considered to be luxury because of the long synthesis time (5-12 days). Here, this material with a highly uniform mesoporous (20 nm) structure was crystallized in a shorter time (20 h) using a crystal-seeds method when an appropriate amount of potassium fluoride was added. Characterization techniques including XRD, SEM, TEM and liquid nitrogen adsorption provided detailed information on the two kinds of porous structure silicalite-1. Due to the "smooth" adsorption surface of silicalite-1 containing few equilibrium ions, it is ideal for the separation of gas mixtures containing non-polar molecules with similar physical properties. Moreover, the CH4, N-2, CO2 and C2H6 adsorption properties were also investigated. Micro porous silicalite-1 has a high adsorption capacity for CH4, N-2, CO2 and C2H6 and adsorption selectivity for CH4/N-2, CO2/N-2, CO2/CH4 and C2H6/CH4. Although a lower adsorption capacity was observed for mesoporous silicalite-1, the pore size did not affect the outstanding adsorption selectivity, on the contrary, the selectivity of mesoporous silicalite-1 was improved.

• 出版日期2017-4
• 单位太原理工大学