Synthesis and Characterization of Zincosilicates with the SOD Topology

The incorporation of Zn^(2+) into tetrahedral framework positions of zeolites with the sodalite topology (SOD) is obtained by direct synthesis. The zincosilicates are characterized by thermal analyses, a Rietveld refinement of powder X-ray diffraction (XRD) data, and infrared (IR) and ^1H, ^(23)Na, ^(13)C, and ^(29)Si MAS NMR spectroscopies. A zinc substitution level as high Si/Zn = 6-7 is achieved and constitutes by far the largest extent of isomorphous substitution by a doubly charged heteroatom in the framework of a zeolite. Two types of β-cage occupancies (TMA^+ and Na^+) are observed.