Abstract
Titanium-containing MFI zeolites (Ti-ZSM-5) have been prepared by gas–solid reaction between highly siliceous ZSM-5 precursors synthesized with different organic molecules, and TiCl 4 vapor at elevated temperature. XRD, FT-IR, UV-Vis, 29 Si and 27 Al solid NMR techniques are used to characterize precursors and Ti-ZSM-5 zeolites. Highly siliceous ZSM-5 synthesized with different templates possesses different amount of internal silanol groups clustered as silanol nests in framework. When the precursor is contacted with TiCl 4 vapor at elevated temperature, titanium atoms are incorporated into the tetrahedral sites by the reaction between TiCl 4 and silanol nests, not by the isomorphous substitution of titanium for framework aluminium or/and silicon. Highly siliceous ZSM-5 precursor synthesized with NBA, TEABr or HDA template possesses relatively large amount of internal silanol groups, and then obtains high concentrations of framework titanium after contacted with TiCl 4 vapor, compared to those synthesized with TPAOH or TPABr template. In addition, Ti-ZSM-5 with precursors obtained by using NBA, TEABr or HDA template can occupy higher catalytic activity in the epoxidation of propylene with diluted hydrogen peroxide.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
