Organic-free,Ultrafast Synthesis of K-CHA Nano-aggregates with Various Morphologies and Their Adsorption Performances  

作　　者：CHU Kailiang WANG Yaquan LIU Wenrong BU Lingzhen HUANG Yitong GUO Niandong QU Liping SANG Juncai LI Yaoning SU Xuemei ZHANG Xian 

机构地区：[1]Key Laboratory for Green Chemical Technology of Ministry of Education,School of Chemical Engineering&Technology,Tianjin University,Tianjin 300072,P.R.China [2]Haihe Laboratory of Sustainable Chemical Transformations,Tianjin 300192,P.R.China

出　　处：《Chemical Research in Chinese Universities》2024年第6期1151-1159,共9页高等学校化学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.21276183).

摘　　要：K-Chabazite(K-CHA)zeolites were synthesized with an ultrafast procedure through an eco-friendly and cost-effective“one-pot”method.By solely employing colloidal silica and aluminum hydroxide in the K^(+)/Sr^(2+)system without the assistance of seeds,fluorides or organic structure as directing agents,the K-CHA nano-aggregates were successfully synthesized in a few hours.The crystallization behavior of the gels with different SiO_(2)/Al_(2)O_(3) molar ratios(SARs)was investigated using X-ray diffraction(XRD);scanning electron microscope(SEM);X-ray fluorescence(XRF);27Al and 29Si magic angle spinning nuclear magnetic resonance(MAS NMR);Fourier-transform infrared spectra(FTIR);UV-Raman characterizations.As the nucleation rates were changed with the SARs,three kinds of K-CHA nano-aggregates,namely,hamburger-,disk-and walnut-shaped,were obtained.A possible formation mechanism of the K-CHA nano-aggregates was proposed.Additionally,the walnut-shaped sample with an SAR of 7 possessed the largest pore volume and specific surface area,resulting in the highest methane adsorption capacity.Furthermore,it exhibited a CH_(4)/N_(2) selectivity of more than 3 under relative pressures ranging from 0 to 0.6.This work offers guidance for modifying the stacking modes of other nano-sized zeolites.

关 键 词：CHABAZITE Organic structure directing agent(OSDA)-free Nano-aggregate Methane Adsorption separation 

分 类 号：O64[理学—物理化学]