01984nas a2200277 4500008004100000022001400041245011000055210006900165260007400234300001200308490000800320520103100328653001601359653001101375653001301386653002401399653001401423653001701437100002701454700002401481700002001505700002501525700002001550700001701570856011901587 2007 eng d a1520-610600aNCL-7, a novel all silica analog of polymorph B rich member of BEA family: synthesis and characterization0 aNCL7 a novel all silica analog of polymorph B rich member of BEA a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbJapan Assoc ZeolitescAPR a108-1140 v1013 a
{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 (*
10aB-polymorph10aDIFFaX10aPromoter10aReitveld refinement10asynthesis10azeolite beta1 aKadgaonkar, Mahesh, D.1 aKasture, Mahesh, W.1 aBhange, Deu, S.1 aJoshi, Praphulla, N.1 aRamaswamy, Veda1 aKumar, Rajiv uhttp://library.ncl.res.in/content/ncl-7-novel-all-silica-analog-polymorph-b-rich-member-bea-family-synthesis-and-0