Synthesis of Fully Dehydrated Partially Cs+-exchanged Zeolite Y (FAU, Si/Al = 1.56),|Cs45Na30|[Si117Al75O384]-FAU and Its Single-crystal Structure

[摘要] Large single crystals of zeolite, |Na₇₅|[Si₁₁₇Al₇₅O₃₈₄]-FAU (Na-Y, Si/Al = 1.56), were synthesized from gels with composition of 3.58SiO₂ : 2.08NaAlO₂ : 7.59NaOH : 455H₂O : 5.06TEA : 2.23TCl. One of these, a colorless single-crystal was ion exchanged by allowing aqueous 0.02 M CsOH to flow past the crystal at 293 K for 3 days, followed by dehydration at 673 K and 1 �? 10-6 Torr for 2 days. The crystal structure of fully dehydrated partially Cs+-exchanged zeolite Y, |Cs₄₅Na₃₀|[Si₁₁₇Al₇₅O₃₈₄]-FAU per unit cell (a = 24.9080(10) A) was determined by single-crystal X-ray diffraction technique in the cubic space group Fd 3 m at 294(1) K. The structure was refined using all intensities to the final error indices (using only the 877 reflections with Fo > 4�?(Fo)) R1 = 0.0966 (Based on F) and R2 = 0.2641 (Based on F2). About forty-five Cs⁺ ions per unit cell are found at six different crystallographic sites. The 2 Cs⁺ ions occupied at site I, at the centers of double 6-ring (D6Rs, Cs-O = 2.774(10) A and O-Cs-O = 88.9(3) and 91.1(3)o). Two Cs⁺ ions are found at site I�? in the sodalite cavity; the Cs⁺ ions were recessed 2.05 A into the sodalite cavity from their 3-oxygen plane (Cs-O = 3.05(3) A and O-Cs-O = 77.4(13)o). Site-II�? positions (opposite single 6-rings in the sodalite cage) are occupied by 7 Cs⁺ ions, each of which extends 2.04 A into the sodalite cage from its 3-oxygen plane (Cs-O = 3.067(11) A and O-Cs-O = 80.1(3)o). The 26 Cs⁺ ions are nearly three-quarters filled at site II in the supercage, being recessed 2.34 A into the supercage (Cs-O = 3.273(8) A and O-Cs-O = 74.3(3)o). The 4 Cs⁺ ions are found at site III deep in the supercage (Cs-O = 3.321(19) and 3.08(3) A), and 4 Cs⁺ ions at another site III�? (Cs-O = 2.87(4) and 3.38(4) A). About 30 Na⁺ ions per unit cell are found at one crystallographic site; The Na⁺ ions are located at site I�? in the sodalite cavity opposite double 6-rings (Na-O = 2.578(11) A and O-Na-O = 97.8(4)o).

[学科分类] 化学（综合）

[关键词] Faujasite-type zeolite;Na-Y;Single-crystal structure;Cesium;Sodium