Synthesis and shaping of mesoporous Molecular sieves and their Applications in bio adsorption and Catalysis

Abstract

The discovery of a new M41S family such as MCM 41 and newlineMCM 48 has opened a new window in many areas of chemistry and materials newlineScience These mesoporous molecular sieves possess large surface area up to newline1000 narrow pore size distribution and high pore volume with the newlinepore diameter in the range of 2 to 10 nm Stucky and co workers have newlinerecently synthesised the powder P form of highly ordered SBA 15 in acidic newlinemedia This material possesses uniform tubular channels ranging from 5 to 30 newlinenm high pore wall thickness and significantly high hydrothermal stability newlineSeveral recent research papers have reported the pore structure of SBA 15 and newlineassess the possibility of tuning the pore diameter Although mesopores are newlinelarge enough to accommodate protein and vitamin molecules the powdered newlinematerial which is obtained from the hydrothermal process could not be newlineused directly for industrial applications Since the mesoporous crystalline newlinepowders are in the particle size of 1 10 and#956;m it is invariably need to be shaped newlineinto bodies such as granules spheres and extrudates Ex prior to their use as newlineadsorbents and catalysts in commercial fixed bed reactor in order to avoid newlineextreme high pressure drop and to achieve high mechanical strength Among newlinethe catalyst bodies preparation of extrudates is an easy process which is newlineusually done by the addition of inorganic binders like bentonite attapulgite newlinekaolin and organic binders such as methylcellulose and hydroxyethylcellulose newline