Synthesis And Characterization Of STW And ITH-type Zeolite

This paper introduces the synthesis and characterization of B-and Ge-substituted STW-type silicate zeolite?denoted as B-STW,GeSi-STW-HT and GeSi-STW-DG?,ITH-type germanosilicate?denoted as GeSi-ITH?,Cu-and Co-containing ITH-zeotype?denoted as Cu-ITH and Co-ITH?.The specific research content are as follows:1.Pure B-STW were synthesized using 2-ethyl-1,3,4-methylimidazole hydroxide solution as organic structure-directing agent?OSDA?in the concentrated sol.The B-STW were characterized by powder X-ray diffraction?XRD?,inductance coupled plasma emission spectrometry?ICP?,scanning electron microscopy?SEM?,N₂ adsorption-desorption,Fourier transform infrared spectroscopy?FT-IR?,and NH₃ temperature-programmed desorption?NH₃-TPD?analysis methods.The effects of synthetic gel composition?the molar ratio of SiO₂/B₂O₃,the concentration of 2E134 TMIOH solution and crystallization time?were studied.2.STW-type silicagermanium were synthesized using N,N'-diethyl ethylenediamine as OSDA by hydrothermal synthesis method and dry-gel method,respectively,and namely as GeSi-STW-HT and GeSi-STW-DG.The GeSi-STW-HT and GeSi-STW-DG were characterized by powder XRD,ICP and SEM.3.GeSi-ITH were synthesized using tetramethyl hexanediamine as OSDA by hydrothermal synthesis method.The GeSi-ITH were characterized by powder and single crystal XRD,ICP,SEM,DT-TGA and N₂ adsorption-desorption.The effects of synthetic gel composition?H₂O,molar ratio of SiO₂/GeO₂,OSDA and fluorine ion?and thermal stability were studied.4.Cu²⁺ and Co²⁺ were introduced into the GeSi-ITH?denoted as Cu-ITH and Co-ITH?,which was by UV-visible diffuse reflectance spectra?DR UV-Vis?and X-ray photoelectron spectroscopy?XPS?analyses.The effects of synthetic gel composition?the content of Cu and Co?and thermal stability were studied.