Synthesis of isomorphously substituted extra-large pore UTL zeolitesElectronic supplementary information (ESI) available: Table giving the details of the most representative synthesis of UTL zeolites; figures showing the XRD patterns and FTIR spectra of adsorbed pyridine for isomorphously substituted UTL zeolites, 1H NMR for 7-ethyl-6-azoniaspiro[5.5]undecane hydroxide. See DOI: 10.1039/c2jm31725g

• Main Authors: Shamzhy, Mariya V, Shvets, Oleksiy V, Opanasenko, Maksym V, Yaremov, Pavel S, Sarkisyan, Liana G, Chlubná, Pavla, Zukal, Arnošt, Marthala, V. Reddy, Hartmann, Martin, ejka, Ji í
• Format: Article
• Language: English
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/c2jm31725g

The influence of various synthesis parameters ( e.g. gel composition, pH of the reaction mixture, duration of crystallization) on the phase selectivity of zeolite formation in germanosilicate reaction medium in the presence of different three-valent heteroatoms (B, Al, Ga, Fe or In) was systematically studied and compared with a controlled crystallization from pure germanosilicate media. The boundary conditions of the formation of the pure phase of isomorphously substituted extra-large pore zeolite UTL were established. In the presence of 1 mol% of the respective heteroelement in the initial gel the pH borders of UTL formation are found to be 7.5-11.9 for Fe-, 7.8-12.0 for B-, 8.2-11.0 for Ga-, 11.0-12.0 for In-, and 11.3-12.0 for Al-containing reaction mixtures. The maximum concentration of heteroelements in the reaction mixture for the successful synthesis of UTL is 1.5 mol% for Al and Ga, 6 mol% for In, and 13 mol% for B. The size of UTL crystals decreases in the order Al- > In- > Ga- > Fe- B-UTL. The nature of isomorphous substituent influences the textural properties (pore size distribution) of the respective UTL zeolites. The optimized conditions of isomorphous substitution of three-valent elements into extra-large pore zeolite UTL were established and discussed in detail.