Synthesis And Characterization Of Heteroatom-substituted Silicogermanates Zeolitic Materials

This paper introduce the synthesis and characterization of heteroatomic substituted BEC-typegermanosilicatezeolite.B-,Cu-andCo-substitutedBEC-type germanosilicatezeolite were prepared through hydrothermal method.Sn-containing BEC-zeotype was prepared by hydrothermal method and postsynthesis method,respectively.The specific research content is as follows:1.B-substituted BEC-type germanosilicate zeolite（denoted as B-BEC）was synthesized using tetramethylethylenediamine as the template.The B-BEC was characterized by powder X-ray diffraction（XRD）,inductance coupled plasma emission spectrometry（ICP）,scanningelectronmicroscopy（SEM）,elementalanalysis,N₂adsorption-desorption and NH₃ temperature programmed desorption（NH₃-TPD）,etc.The effect of synthetic gel composition and thermal stability were studided.2.Pure Cu-and Co-substituted BEC-type germanosilicate zeolite were synthesized by using tetramethylethylenediamine as the template.The B-BEC was characterized by XRD,SEM,elemental analysis,N₂ adsorption-desorption and UV-visible diffuse reflectance spectra（DRS-UV/Vis）,etc.The effect of synthetic gel concentration and thermal stability were studied.3.Sn-containing BEC-type germanosilicate zeolite was synthesized by hydrothermal method and post-synthesis（denoted as Sn-BEC and Sn-BEC-PS）.The Sn-BEC and Sn-BEC-PS were characterized by XRD,SEM,elemental analysis,N₂adsorption-desorption and UV-visible diffuse reflectance spectra（DRS-UV/Vis）and X-ray photoelectron spectroscopy（XPS）,etc.The effects of synthetic gel concentration（molar ratio of SiO₂/SnO₂）and thermal stability were studied,and the catalytic activity was preliminarily studied.4.Other zeolites,with AST-,BEC-and MFI-zeotype structure,synthesized by using different organic amines as templates were summarized.