Synthesis of MCM-22 zeolite by an ultrasonic-assisted aging procedure.
The synthesis of MCM-22 zeolite under hydrothermal crystallization conditions has been performed by an ultrasonic-assisted aging procedure. The ultrasonic-assisted aging of the initial aluminosilicate gel can shorten the crystallization time of MCM-22, decrease the amount of hexamethyleneimine (HMI) used, and broaden the range of SiO(2)/Al(2)O(3) ratios. By using the ultrasonic aging, pure phase of high-silica MCM-22 products with SiO(2)/Al(2)O(3)>100 can be obtained. When SiO(2)/Al(2)O(3) <or= 50, high crystalline MCM-22 zeolites with the reduced average crystal sizes can be made even with low HMI/SiO(2) ratio of 0.05 under static crystallization conditions. The acoustic cavitation of the ultrasonic is believed to be responsible for these positive results due to its cracking the crystal seeds and improving the solubility of silicate species.
Wang
Baoyu
B
Institute of New Catalytic Materials Science, College of Chemistry, Nankai University, Tianjin 300071, PR China.
Wu
Jianmei
J
Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.
Yuan
Zhong-Yong
ZY
Institute of New Catalytic Materials Science, College of Chemistry, Nankai University, Tianjin 300071, PR China. Electronic address: zyyuan@mail.nankai.edu.cn.
Li
Niu
N
Institute of New Catalytic Materials Science, College of Chemistry, Nankai University, Tianjin 300071, PR China.
Xiang
Shouhe
S
Institute of New Catalytic Materials Science, College of Chemistry, Nankai University, Tianjin 300071, PR China. Electronic address: shxiang@public.tpt.tj.cn.
D000537:Aluminum Oxide / Q000737:chemistry; D018797:Cell Cycle Proteins / Q000737:chemistry*; D003460:Crystallization; D018386:Kinetochores; D008855:Microscopy, Electron, Scanning; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry*; D012822:Silicon Dioxide; D014465:Ultrasonics; D014961:X-Ray Diffraction; D017641:Zeolites / Q000138:chemical synthesis*
D018797:Cell Cycle Proteins; C118345:MCM22 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017641:Zeolites; D012822:Silicon Dioxide; D000537:Aluminum Oxide