Single-Crystal Structure of Fully Dehydrated and Partially Dealuminated Zeolite Y (FAU, Si/Al = 1.56) Mn2+ Exchanged by Flow Method

Abstract

The single-crystal structure of fully dehydrated zeolite Y (FAU, Si/Al = 1.56) Mn2+ exchanged by flow method, |Mn31(Mn4AlO4)H10|[Si117Al75O384]-FAU, was determined by single-crystal synchrotron X-ray diffraction techniques. It was refined to the final error indices R 1/wR 2 = 0.0692/0.2026 in the cubic space group $$Fd\overline{3}m$$ at 100(1) K. In this structure, 35 Mn2+ ions per unit cell are found at four crystallographic positions: 11 and 7 are at the centers of the double 6-rings (site I) and in the sodalite cavity opposite the double 6-rings (site I′), respectively. The remaining 4 and 13 are found at sites II′ (near 6-ring in the sodalite cavity) and II (near 6-ring in the supercage), respectively. Some dealumination of the zeolite framework occurred during Mn2+ exchange. The four non-framework oxygen atoms coordinate to a aluminate ion at the center of sodalite cavity (site U) and 4 Mn2+ ions at site II′ to give Mn4AlO4 3+. The 10 H+ ions are required for charge balance in fully dehydrated Mn2+-Y. The single-crystal structure of fully dehydrated, partially dealuminated, and Mn2+-exchanged zeolite Y (FAU (Si/Al = 1.56) was determined by single-crystal synchrotron X-ray diffraction techniques.