3D Electron Diffraction Unravels the New Zeolite ECNU‐23 from the "Pure" Powder Sample of ECNU‐21. (27th November 2019)

• Record Type: Journal Article
• Authors: Liu, Xue; Luo, Yi; Mao, Wenting; Jiang, Jingang; Xu, Hao; Han, Lu; Sun, Junliang; Wu, Peng
• Is Part Of: Angewandte Chemie. Volume 132:Number 3(2020)
• Page Start: 1182
• Page End: 1186
• Publication Date: 2019-11-27
• Subjects: 3D-Elektronenbeugung -- Alkalische Behandlung -- Heterogene Katalyse -- Zeolithe -- Strukturaufklärung; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201912488
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: A novel crystalline high‐silica zeolite with 12×8‐membered ring (R) channel system is prepared with the aid of the 3D electron diffraction (3D ED) technique. A crystal with the same topology as one of the predicted daughter structures of CIT‐13 germanosilicate, named ECNU‐23 (East China Normal University 23) was coincidentally detected by the 3D ED investigation during the structure characterization of the "pure" powder sample of existing one‐dimension (1D) 10‐R ECNU‐21. By controlling the alkaline‐assisted hydrolysis under moderate conditions, we purified the phase of ECNU‐23 by selectively breaking and removing the chemically weak Ge(Si)‐O‐Ge and metastable Si‐O‐Si bonds. Its structure was determined based on the 3D ED data, and confirmed by high‐resolution TEM images and powder X‐ray diffraction (PXRD) data. The aluminosilicate Al‐ECNU‐23 shows unique catalytic properties in the isomerization/ disproportionation of m ‐xylene as solid‐acid catalyst. Abstract : Auf Beugen und Brechen : Eine neuer, hochkristalliner Zeolith, ECNU‐23, wurde durch Hydrolyse im Alkalischen unter Bruch schwacher Ge(Si)‐O‐Ge‐ und metastabiler Si‐O‐Si‐Bindungen mit Unterstützung einer 3D‐Elektronenbeugungs (ED)‐Technik erhalten. Das Alumosilicat Al‐ECNU‐23 zeigt einzigartige katalytische Eigenschaften bei der Isomerisierung/Disproportionierung von m ‐Xylol als fester Säurekatalysator.