Amorphous Ti species in titanium silicalite-1: Structural features, chemical properties, and inactivation with sulfosalt

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• 作者：Ji Su^a ; Guang Xiong^a ; Juncheng Zhou^a ; ^b ; Wenhuan Liu^a ; Danhong Zhou^c ; Guiru Wang^a ; Xiangsheng Wang^a ; Hongchen Guo^a ; ^{Hongchenguo@163.com}
• 关键词：TS-1 ; Amorphous Ti species ; UV Raman spectroscopy ; Resonance enhancement ; Hammett indicator titration ; Sulfosalt inactivation
• 刊名：Journal of Catalysis
• 出版年：2012
• 出版时间：April, 2012
• 年：2012
• 卷：288
• 期：Complete
• 页码：1-7
• 全文大小：762 K

文摘

The nature of the amorphous Ti species in titanium silicalite-1 (TS-1) was investigated by UV Raman spectroscopy (UV Raman), UV-vis diffuse reflectance spectroscopy (UVDRS), infrared spectroscopy (IR), and Hammett indicator titration methods. A new Raman feature at 700 cm^?, which is closely related to the UVDRS band at 260-280 nm, is first assigned to a totally symmetric vibration of hexacoordinated Ti-O-Ti linkages of the amorphous Ti species. The amorphous Ti species in TS-1 can be formed easily under the synthesis conditions in the presence of Na⁺ or after treatment in ammonia solution. The results reveal that the amorphous Ti species is the main factor in the enhanced acidity and H₂O₂ decomposition ability of TS-1. A sulfosalt impregnation method has been proved effective in reducing the adverse effect of the amorphous Ti species.