Bridging the Gap between Structurally Distinct 2D Lamellar Zeolitic Precursors through a 3D Germanosilicate Intermediate

Abstract

There is broad scientific interest in lamellar zeolitic materials for alarge variety of technological applications.The traditional synthetic methods towards two-dimensional (2D) zeolitic precursors have made ag reat impact in the construction of families of related zeolites;h owever,t he connection between structurally distinct 2D zeolitic precursors is muchless investigated in comparison, thereby resulting in as ynthetic obstacle that theoretically limits the types of zeolites that can be constructed from eachlayer.Herein, we report aGe-recycling strategy for the topotactic conversion between different 2D zeolitic precursors through at hree-dimensional (3D) germanosilicate.Specifically,the intermediate germanosilicate can be constructed within 150 min by taking advantage of its structural similarity with the parent lamellar precursor.This process enables the conversion of one 2D zeolitestructure into another distinct structure,t hus overcoming the synthetic obstacle between two families of zeolitic materials.

IZM-7: A new stable aluminosilicogermanate with a promising catalytic activity

“…The Attenuated Total Reflectance Infrared spectroscopy, ATR-IR spectra (Figure S4 and Table S1) of the as prepared IM-12 and of the treated samples agree with the XRF results. Only the as prepared sample has a band at 900 cm -1 attributed to Ge-O-Ge [20]. The absence of this band in the treated samples is consistent with the increase of the Si/Ge molar ratio from 5 to 10 after the SiCl 4 treatment and to 173 after the PAC treatments.…”

“…In addition, the shift of the band at 1054 cm -1 in the IM-12_Si to 1043 cm -1 in the IZM-7 suggests the incorporation of Al in the framework. The band characteristic of the vibration of d4r units [20,21] around 580 cm -1 , is present in all samples proving that these building units remained after the treatments and justifying the upholding of the UTL structure seen in the XRD patterns. This band presented a shift from 570 cm -1 in the as prepared IM-12 to ≃ 582 cm -1 after the treatments suggesting that Ge was replaced by other elements in the d4r.…”

“…Moreover, the band at 950 cm -1 attributed to asymmetric stretching vibration of Si-O-Ge in the framework [20,21] decreased with the increase of the Si/Ge molar ratio after the treatments. In addition, the shift of the band at 1054 cm -1 in the IM-12_Si to 1043 cm -1 in the IZM-7 suggests the incorporation of Al in the framework.…”