Fe-ZSM-35,as a zeolite with ferrierite-like structure,is an important catalyst in industry,and it is usually very difficult to obtain through conventional methods.Understanding the semi-crystallized structure at the n...Fe-ZSM-35,as a zeolite with ferrierite-like structure,is an important catalyst in industry,and it is usually very difficult to obtain through conventional methods.Understanding the semi-crystallized structure at the nanoscale is the key to control their properties and design the best materials for their ever increasing uses.Herein,we report a novel and controllable method for the synthesis of Fe-ZSM-35 with pure framework Fe species;the essence of this novel synthetic method is a two-step static hydrothermal process.Initially,semi-crystallized Fe-containing species and a semi-crystallized ZSM-35 structure are prepared,then the two semi-crystallized materials are mixed and crystallized to give Fe-ZSM-35 zeolite.This method can almost eliminate the retarding crystallization effect of hetero Fe and is beneficial for a high content of Fe to be incorporated into the ZSM-35 framework.The formation mechanism of Fe-ZSM-35 zeolite was also investigated by UV Raman spectroscopy in combination with X-ray powder diffraction and UV-vis diffuse reflectance spectroscopy.The studies indicate that the Fe-containing aluminate-silica gel was initially mixed with the semi-crystallized ZSM-35 structure fragments to generate the Fe-ZSM-35 structure,and this method may be extended to the other metal-hetero zeolites.展开更多
基金financially supported by National Key R&D Program of China(2017YFB0702800)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB17000000)the National Major Scientific Instruments and Equipment Development Project of the National Natural Science Foundation of China(2152780065).
文摘Fe-ZSM-35,as a zeolite with ferrierite-like structure,is an important catalyst in industry,and it is usually very difficult to obtain through conventional methods.Understanding the semi-crystallized structure at the nanoscale is the key to control their properties and design the best materials for their ever increasing uses.Herein,we report a novel and controllable method for the synthesis of Fe-ZSM-35 with pure framework Fe species;the essence of this novel synthetic method is a two-step static hydrothermal process.Initially,semi-crystallized Fe-containing species and a semi-crystallized ZSM-35 structure are prepared,then the two semi-crystallized materials are mixed and crystallized to give Fe-ZSM-35 zeolite.This method can almost eliminate the retarding crystallization effect of hetero Fe and is beneficial for a high content of Fe to be incorporated into the ZSM-35 framework.The formation mechanism of Fe-ZSM-35 zeolite was also investigated by UV Raman spectroscopy in combination with X-ray powder diffraction and UV-vis diffuse reflectance spectroscopy.The studies indicate that the Fe-containing aluminate-silica gel was initially mixed with the semi-crystallized ZSM-35 structure fragments to generate the Fe-ZSM-35 structure,and this method may be extended to the other metal-hetero zeolites.
