Formation mechanism of three-membered ring containing microporous zincosilicate RUB-17

Impact of the Zn source on the RSN-type zeolite formation

“…The peak positions in all of the patterns coincide with RSN framework type material. TG and dTG curves of selected solids all match well with the reference RUB-17 17 meaning that the composition of the final product and the water content in the samples are nearly identical ( Figure S4). Furthermore, the Si/Zn ratios of the materials (Table S1) vary around the expected value of 3.5 in accordance with the particular site that zinc occupies in the RSN-type framework.…”

“…Synthesis of materials containing various T atoms. In order to study the impact of the presence of T atoms other than zinc, reaction mixtures have been prepared in a procedure analogous to the one reported in reference 17 . The molar oxide composition of the studied reaction mixtures was 1 SiO2 : 0.1 TO : 0.5 NaOH : 0.5 KOH : 0.08 TEAOH : 44 H2O.…”

“…Zincosilicate RUB-17 was prepared as previously described. 17 Needed amounts of sodium hydroxide (pellets, 97%, Acros organics), potassium hydroxide (pellets, 85%, Kemika), tetraethylammonium hydroxide (TEAOH, 35% water solution, Aldrich), a zinc source, and doubly distilled water were mixed. The employed zinc sources were zinc oxide (ZnO, 99.9%, Ventron), zinc chloride (ZnCl2, 98%, Sigma), zinc bromide (ZnBr2, purum p.a., Fluka), zinc nitrate hexahydrate (Zn(NO3)2•6H2O, p.a., Kemika), zinc acetate dihydrate (Zn(OAc)2•2H2O, p.a., Kemika), zinc acetylacetonate monohydrate (Zn(acac)2•H2O, prepared according to the previously published procedure 19 ) and zeolitic imidazolate framework material number 8 (ZIF-8, prepared according to the previously published procedure 20 ).…”

“…30 The molar oxide composition of the starting reaction mixtures and the chemicals used are similar with those employed in the RUB-17 preparation. 17 The chemicals employed as the sources of T atoms, the crystallization periods (tC) and the final products are listed in the Table 1. Representative X-ray powder diffraction patterns of the obtained solids are displayed in Figure S2.…”

“…Herein, the zincosilicate material RUB-17, which is so far the only known RSN-type zeolite material, is investigated. 17 Its structure is built of 3-, 4-, 5-, and 6-membered rings forming a tridimensional system of channels 9(3.3×4.4Å) × 9(3.1×4.3Å) × 8(3.4×4.1Å). 3MR frameworks are of particular importance since it has been theoretically predicted that the structures composed of small rings (3MRs and 4MRs) should exhibit lower framework density.…”