%0 Journal Article %J Microporous and Mesoporous Materials %D 2007 %T NCL-7, a novel all silica analog of polymorph B rich member of BEA family: synthesis and characterization %A Kadgaonkar, Mahesh D. %A Kasture, Mahesh W. %A Bhange, Deu S. %A Joshi, Praphulla N. %A Ramaswamy, Veda %A Kumar, Rajiv %K B-polymorph %K DIFFaX %K Promoter %K Reitveld refinement %K synthesis %K zeolite beta %X

{Polymorph B-rich BEA type structure, NCL-7, was synthesized using hydrothermal method in fluoride medium using perchloric acid as promoter. The samples were characterized using XRD, low temperature N-2-adsorption and Si-29 MASNMR. As the structure of beta is highly disordered Rietveld refinement of powder XRD patterns is precluded. Phase composition is derived using the simulated patterns for the random intergrowths of polymorph A and B by DIFFaX. The stacking direction c' is perpendicular to the a'b' plane of the layer. The composition of polymorph B is found to be ca. 60-65%. Two other structures namely NCL-5 and NCL-6 with varying degree of polymorph B enrichment were also synthesized. Synthesis parameters such as effect of H2O/SiO2, TEAOH/SiO2, HClO4/SiO2 and crystallization temperature were studied thoroughly. The present article explains for the first time the synthesis and characterization of NCL-7, an analog of BEA type family with enrichment of polymorph B and its comparison with normal beta (*

%B Microporous and Mesoporous Materials %I Japan Assoc Zeolites %C 1155 16TH ST, NW, WASHINGTON, DC 20036 USA %V 101 %P 108-114 %8 APR %G eng %N 1-2 %9 Article %3

Foreign

%4 3.349 %R 10.1016/j.micromeso.2006.10.033