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Influence of silica resource from rice husk on structure of HZSM-5 zeolite

Characterization results revealed that HZSM-5 material synthesized from rice husk silica has crystallinity and acidity as high as HZSM-5 sample synthesized from glasses water. HZSM-5 material synthesized from rice husk silica not only has the conventional pores system as shown structure of HZSM-5 sample synthesized from glasses water, but also has mesoporous system with kinetic diameter in range of 10-50 nm. | Journal of Chemistry, Vol. 47 (5), P. 586 - 590, 2009 INFLUENCE OF SILICA RESOURCE FROM RICE HUSK ON STRUCTURE OF HZSM-5 ZEOLITE Received 10 October 2008 Le Thi Hoai Nam, Nguyen Thi Thanh Loan Institute of Chemistry, Vietnam Academy of Science and Technology Abstract HZSM-5 zeolites were successfully synthesized by hydrothermal treament using silica from rice husk and glasses water. The samples were characterized by XRD, IR, SEM, TEM, BET and 27 Al-NMR methods. Characterization results revealed that HZSM-5 material synthesized from rice husk silica has crystallinity and acidity as high as HZSM-5 sample synthesized from glasses water. HZSM-5 material synthesized from rice husk silica not only has the conventional pores system as shown structure of HZSM-5 sample synthesized from glasses water, but also has mesoporous system with kinetic diameter in range of 10-50 nm. This multi-porous system is expected to increase significantly the catalytic activity of synthesized material in the reactions with the present of large molecules . Keywords: Rice husk silica, ZSM-5, multi-porous system. I - INTRODUCTION ZSM-5 zeolite is one of the most used catalysts because it has high thermal-hydrothermal durability and is suitable material for the catalyst, adsorption processes, especially for the cracking reaction [1]. ZSM-5 zeolite is synthesized by many different methods. Silica resource for ZSM5 zeolite preparation is plentiful as TEOS, Ludox which are expensive [ 2]. Moreover, traditional ZSM-5 zeolite with small pore diameter of 5 – 6 Å is limited in the reactions with large molecules. Rice husk is the milling byproduct of rice and is a major waste material of the agricultural industry. In Vietnam, annual rice husk quantity is 5 million tons [3]. However, rice husk has little or no commercial application. Therefore, the reusing of rice husk with high value is of great interest of many researchers. Rice husk main compositions are metal oxides, where the SiO2 content is over .