Determination of Si/Al Ratio of Faujasite-type Zeolite by Single-crystal X-ray Diffraction Technique. Single-crystal Structures of Fully Tl + - and Partially K + -exchanged Zeolites Y (FAU), |Tl 71 |[Si 121 Al 71 O 384 ]-FAU and |K 53 Na 18 |[Si 121 Al 71 O 384 ]-FAU

摘要: Large colorless single crystals of faujasite-type zeolite with diameters up to 200 /an have been synthesized from gels the composition 3.58SiO 2 :2.08NaAlO :7.59NaOH:455H O:5.06TEA:1.23TCl. Two these, octahedron about μm in cross-section treated aqueous 0.1 M TlC H 3 O and KNO order prepare Tl + - K -exchanged zeolites, respectively, then determined Si/Al ratio framework. The crystal structures |Tl 71 |[Si 121 Al 384 ]-FAU |K 53 Na 18 per unit cell, a = 24.9463(2) 24.9211(16) A, dehydrated at 673 1 x 10 -6 Torr, by single-crystal X-ray diffraction techniques cubic space group Fd3 m 294 K. two were refined using all intensities final error indices (using only 905 429 reflections for which F o > 4σ(F )) R /R 0.059/0.153 0.066/0.290, respectively. In structure fully zeolite, ions cell are located four different crystallographic sites. Twenty-nine fill site I' sodalite cavities on 3-fold axes opposite double 6-rings (Tl-O 2.631(12) A O-Tl-O 93.8(4)°). Another 31 II supercage 2.782(12) 87.9(4)°). About found III 2.91(6) 3.44(3) A), remaining 8 occupy another 2.49(5) 3.06(3) A). partially five sites 4 I, center hexagonal prism (K-O 2.796(8) O-K-O 89.0(3)°). cavity 2.570(19) O-KO 99.4(9)°). Twenty-two 2.711(9) 94.7(3)°). 5 deep 2.90(5) 3.36(3) 12 III' 2.55(3) 2.968(18) Twelve also lie (Na-O 2.292(10) O-Na-O 117.5(5)°). 6 2.390(17) 113.1(11)°). synthetic is 1.70 occupations cations, 71, structures.