Please wait a minute...
Acta Physico-Chimica Sinica  1994, Vol. 10 Issue (06): 514-520    DOI: 10.3866/PKU.WHXB19940607
Studies on the Control of the Pore-opening Size of HM Zeolite and its Para-selectivity
Tang Yi, Lu  Lu, Gao Zi
Chemistry Department, Fudan University, Shanghai 200433
Download:   PDF(1086KB) Export: BibTeX | EndNote (RIS)      


The fine control of the pore-opening size of HM zeolite by chemical vapor deposition of Si(OCH_3)_4 has been investigated. Si(OCH_3)_4 can be deposited by reaction with the hydroxyl groups on the zeolie. After calcination in oxygen silica is deposited on the externai surface of the zeolite and produces silica coated HM zeolite (SiHM). The SiHM samples with different amount of silica deposited have been characterized by adsorption experiments and temperature-programmed desorption of NH_3. It has been found that the deposition of silica does not change the acidity of the zeolite internal surface but reduces the pore-opening size. For toluene disproportionation reaction the para-selectivity of the SiHM zeolite catalysts is increased markedly. Under the same reaction conversion the mole fraction p-xylene in the xylene mixture can be raised up to above 0.40 when using SiHM as the reaction catalyst instead of the original HM zeolite. For isomerization of o-xylene the improvement in para-selectivity has not been observed, because the reaction is not mainly controlled by the diffusion of the reaction products.

Key wordsMordenite      Pore-opening modification      Toluene disproportionation      o-xylene isomerization     
Received: 14 January 1993      Published: 15 June 1994
Corresponding Authors: Gao Zi   
Cite this article:

Tang Yi, Lu Lu, Gao Zi. Studies on the Control of the Pore-opening Size of HM Zeolite and its Para-selectivity. Acta Physico-Chimica Sinica, 1994, 10(06): 514-520.

URL:     OR

[1] LI Bin WANG Hong DING Fu-Chen LI Cui-Qing SONG Yong-Ji KE Ming REN Cui-Tao. Effects of Preparation Methods on the Catalytic Performance of Selective Catalytic Reduction of NO with CH4 over Co-MOR Catalysts[J]. Acta Physico-Chimica Sinica, 2013, 29(06): 1289-1296.
[2] MENG Gen, KONG De-Jin, QI Xiao-Lan, XU Zhong-Qiang. Carbon Deposition on a Toluene Disproportionation and Transalkylation Catalyst[J]. Acta Physico-Chimica Sinica, 2010, 26(11): 3017-3022.
[3] LIU Jie-Xiang, WEI Xian, ZHANG Xiao-Guang, HAN En-Shan. Acidities of Cu-[M’]MORand Ag-[M’]MOR (M’=B, Al, Ga, Fe)[J]. Acta Physico-Chimica Sinica, 2009, 25(10): 2123-2129.
[4] LIU Jie-Xiang; WEI Xian; ZHANG Xiao-Guang; WANG Gui-Xiang; HAN En-Shan; WANG Jian-Guo. NOx Adsorption in [Ag]-AlMOR Molecular Sieve[J]. Acta Physico-Chimica Sinica, 2009, 25(01): 91-96.
[5] LI Fei-Fei; GUI Xing-Hua; LIU Dao-Sheng; SONG Li-Juan; SUN Zhao-Lin. Ethene Adsorption on Mordenite and Modified Mordenite[J]. Acta Physico-Chimica Sinica, 2008, 24(04): 659-664.
[6] LIU Bai-Jun; ZENG Xian-Jun; WANG Hui; HUANG Yong; WANG Mei. Crystal Transformation among ZSM-5, ZSM-57 andMordenite[J]. Acta Physico-Chimica Sinica, 2007, 23(04): 503-507.
[7] QI Xiao-lan; WANG Zhan; LI Shi-jie; LI Bin; LIU Xi-yao; LIN Bing-xiong. Characterization of High Silica Mordenite Synthesized from Amine-free System Using Fluoride as Structure-directing Agent[J]. Acta Physico-Chimica Sinica, 2006, 22(02): 198-202.
[8] Yuan Shu-Ping;Wang Jian-Guo;Li Yong-Wang;Peng Shao-Yi. Ab initio Study on B, Al or Ga Isomorphously Substituted Mordenites[J]. Acta Physico-Chimica Sinica, 2001, 17(09): 811-816.
[9] Li Bang-Yin; Gao Zi. The Influence of Dealumination Methods on the Properties of Mordenites[J]. Acta Physico-Chimica Sinica, 1991, 7(01): 1-9.