Three single crystals of excessively Cd2+-exchanged zeolite Y were prepared by the exchange of Na-Y (|Na75|[Si117Al75O384]-FAU, Si/Al = 1.56) with an aqueous stream 0.25 M each in Cd(NO3)2 and Cd(C2H3O2)2 at 294 K (crystals 1 and 2) and 353 K (crystal 3), followed by vacuum dehydration at 1 � 10-6 Torr and 423 K (crystal 1) and 723 K (crystals 2 and 3).  Their crystal structures were determined crystallographically using synchrotron X-radiation in the cubic space group Fd3-m.  They were refined to the final error indices R1/wR2 = 0.0498/0.1395, 0.0702/0.1960, and 0.0643/0.1747 for crystals 1, 2, and 3, respectively.  The number of Cd2+, H2O, OH-, and O2- ions or molecules in the three crystal structures are about 43.5, 23, 12, 0; 43.5, 0, 0, 6; and 47.5, 0, 0, 10 per unit cell for crystals 1, 2, and 3, respectively.  In all cases, over-exchange due to uptake of OH- occurred.  Crystals 1 and 2 had imbibed about 6 Cd(OH)2 molecules per unit cell, perhaps as CdOH+ ions, crystal 3 ten, indicating this increase in imbibition as temperature increased from 294 K to 353 K.  These decomposed upon vacuum dehydration at 723 K to give, with additional Cd2+ ions, Cd8O48+ clusters (symmetry 4-3m(Td)) in the sodalite cavities of crystals 2 and 3.  The crystal compositions are |Cd8.5(CdOH)12(CdOH2)23|[Si117Al75O384]-FAU (crystal 1), |Cd31.5(Cd8O4)1.5|[Si117Al75O384]-FAU (crystal 2), and |Cd27.5(Cd8O4)2.5|[Si117Al75O384]-FAU (crystal 3).

Three single-crystal structures of Cd<sup>2+</sup>-exchanged zeolite Y (FAU).  Cd(OH)<sub>2</sub> imbibition increases with increasing ion exchange temperature

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Three single-crystal structures of Cd2+-exchanged zeolite Y (FAU). Cd(OH)2 imbibition increases with increasing ion exchange temperature

Three single-crystal structures of Cd²⁺-exchanged zeolite Y (FAU). Cd(OH)₂ imbibition increases with increasing ion exchange temperature