In view of the limitation of channel transport in the traditional microporous TS-1 zeolite and the problem of low catalytic activity,three kinds of TS-1 zeolite catalysts with different channel structures and titanium species distribution patterns were prepared by alkali corrosion method,and further characterized by SEM,TEM,XRD,N2 adsorption-desorption isotherm,FT-IR,UV-Raman,XPS and NMR;their catalytic performance for styrene oxidation reaction was also evaluated.The results show that compared with the post-treatment with sodium hydroxide(NaOH)or tetrapropylammonium hydroxide(TPAOH),TS-1 zeolite(TS-1-TE)treated with the mixed solution of TPAOH and ethanolamine(EOA)has the larger external specific surface area and mesoporous pore volume,which effectively improves the flow and diffusion efficiency of guest molecules.Meanwhile,owing to the coordination between EOA and titanium species as well as the recrystallization of TPAOH,the four-coordinated titanium species separated from the framework can exist in zeolite framework in the form of mononuclear six-coordinated titanium species;the framework is conducive to improving the activity of catalyst.Under the conditions of reaction temperature 60 ℃,reaction time 6 h,reaction pressure 0.116 MPa and catalyst dosage 50 mg,TS-1-TE catalyst shows the highest activity,the conversion rate of styrene is 74.9％,and the conversion number of six-coordinated titanium atoms is 197.
TS-1 zeoliterecrystallizationsix-coordinated Ti specieshierarchical porousstyrene oxidation
维普
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