A Crystallographic Study of the Decomposition of NO in Fully Indium Exchanged Zeolite Y. In+, In3+, and In3+–NO3– Complexes with Facially Coordinating Nitrate Ions Are in Supercages. Distorted Cubic In4O44+ Clusters Fill Sodalite Cavities

Abstract

The reaction of nitric oxide with fully dehydrated, fully In-exchanged zeolite Y (In–Y, FAU with Si/Al = 1.69) yields zeolite Y with distorted cubic In4O44+ cations, one per sodalite cavity, and In3+–NO3– complexes with facially coordinating nitrate ions in the supercages. With only trigonal coordination, additional In3+ and In+ ions occupy supercage sites. |In3+4.6In+17.9(In4O44+)8(In3+–NO3–)4.2|[Si121Al71O384]–FAU was prepared by the reaction of In–Y with 300 Torr of NO(g) at 673 K under anhydrous conditions. Its structure was determined by single-crystal crystallography with synchrotron X-radiation. It was refined in the space group Fd3m (a = 24.617(1) A) with all 1145 unique data; the final error index, R1 = 0.081, was calculated using only the 988 reflections with Fo > 4σ(Fo). Upon reaction with NO, most of the In+ ions and the few In2+ ions in In–Y were oxidized to In3+. Most of these In3+ ions are members of In4O44+ clusters and In3+–NO3– complexes; NO has reacted to form O2–, NO3–, and apparently...