Structure of the first silicate molecular sieve with 18-ring pore openings, ECR-34.

摘要: The three-dimensional microporosity of zeolite frameworks have allowed their widespread use in industry as heterogeneous catalysts, absorbents, and ion-exchangers. While the phosphate analogues zeolites having up to 24 tetrahedral atoms pore openings are known, silicate-based have, until now, been limited 14-membered ring openings. We now disclose structure characterization synthetic ECR-34, which can be prepared from a mixed alkali metal reaction gel containing tetraethylammonium (TEA) cations. Its has determined powder diffraction data shows ECR-34 hexagonal with dimensions a, b = 21.030(1) A, c 8.530(1) one-dimensional, 18-ring pores 10 A diameter free is stable 800 °C able absorb ion-exchange large organic molecules. existence suggests potential preparing other thermally silicate molecular sieves extra-large pores.