Role of pentahedrally coordinated titanium in titanium silicalite-1 in propene epoxidation
发表时间：2019-03-09
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- 论文类型：
- 期刊论文
- 第一作者：
- Zuo, Yi
- 通讯作者：
- Guo, XW (reprint author), Dalian Univ Technol, State Key Lab Fine Chem, PSU DUT Joint Ctr Energy Res, Sch Chem Engn, Dalian 116024, Peoples R China.
- 合写作者：
- Fischer, Daniel,Liu, Min,Zhang, Ting,Hong, Luwei,Guo, Xinwen,Song, Chunshan,Chen, Yongsheng,Zhu, Pengyu,Jaye, Cherno
- 发表时间：
- 2015-01-01
- 发表刊物：
- RSC ADVANCES
- 收录刊物：
- SCIE、EI、Scopus
- 文献类型：
- J
- 卷号：
- 5
- 期号：
- 23
- 页面范围：
- 17897-17904
- ISSN号：
- 2046-2069
- 摘要：
- Two titanium silicalite-1 samples with different crystal sizes were synthesized in the tetrapropylammonium bromide (TPABr) and tetrapropylammonium hydroxide (TPAOH) hydrothermal systems. The small-crystal TS-1 with a size of 600 nm was then treated with different organic bases. These TS-1 samples were evaluated in the epoxidation of propene, and characterized by ultraviolet-visible diffuse reflectance (UV-vis), X-ray absorption near edge structure (XANES) and Raman spectroscopies. The Ti L-edge absorption spectra show that a new Ti species, pentahedrally coordinated Ti, appears in some of the samples. This pentahedrally coordinated Ti species is correlated with the catalytic oxidation activity of TS-1, closely. Tetrahedrally coordinated Ti in TS-1 is the primary active center for selective oxidation reactions, but the existence of a small amount of pentahedrally coordinated Ti can further improve the catalytic activity. A high molar ratio of Si/Ti (n(Si/Ti)) in the synthesis process (n(Si/Ti) = 92.78) was beneficial for the generation of pentahedrally coordinated Ti. The improved catalytic activity of the TPAOH treated TS-1 is mainly due to the increasing amount of pentahedrally coordinated Ti, besides the elimination of diffusion limitation. Slowing down the crystallization rate can also increase the content of pentahedrally coordinated Ti.
- 是否译文：
- 否
