UV resonance Raman spectroscopic insight into titanium species and structure-performance relationship in boron-free Ti-MWW zeolite

被引：38

作者：

Jin, Shaoqing ^{[1
]}

Wang, Zhendong ^{[1
]}

Tao, Guiju ^{[1
]}

Zhang, Shilin ^{[1
,2
]}

Liu, Wei ^{[1
]}

Fu, Wenhua ^{[1
]}

Zhang, Bin ^{[1
]}

Sun, Hongmin ^{[1
]}

Wang, Yangdong ^{[1
]}

Yang, Weimin ^{[1
,2
]}

机构：

[1] SINOPEC Shanghai Res Inst Petrochem Technol, State Key Lab Green Chem Engn & Ind Catalysis, Shanghai 201208, Peoples R China

[2] East China Univ Sci & Technol, Sch Chem Engn, Shanghai 200237, Peoples R China

来源：

JOURNAL OF CATALYSIS | 2017年 / 353卷

基金：

中国博士后科学基金; 中国国家自然科学基金;

关键词：

Boron-free Ti-MWW zeolite; Titanium species; UV resonance Raman; Acid treatment; Structure-performance relationship; TS-1; ZEOLITE; EXTRAFRAMEWORK TITANIUM; HYDROTHERMAL SYNTHESIS; CATALYTIC PERFORMANCE; TITANOSILICATE; EPOXIDATION; OXIDATION; SILICALITE-1; PROPYLENE; FRAMEWORK;

D O I：

10.1016/j.jcat.2017.07.032

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The titanium species and structure-performance relationship in boron-free Ti-MWW zeolite have been thoroughly studied by 244 nm excited UV resonance Raman spectroscopy for the first time. It was surprisingly found out that acid treatment not only removed a part of the dominant non-framework TiOm (m = 5, 6) species but also made most of them transformed into TiO4 species, which has never been reported before. Interestingly, acid treatment of as-synthesized and directly calcined Ti-MWW resulted in the formation of active framework TiO4 species and inactive TiO4 species in amorphous SiO2 matrix, respectively. Only the samples obtained from acid treatment of as-synthesized Ti-MWW and subsequent calcination showed catalytic activity in 1-hexene epoxidation. Importantly, despite higher Si/Ti ratio, framework Ti(OSi)(4) species-dominant Ti-MWW showed better catalytic performance than the relatively hydrophilic framework Ti(OSi)(3)OH species-dominant one. These understandings would be beneficial for further study of Ti-MWW and development of highly efficient titanosilicate zeolites. (C) 2017 Elsevier Inc. All rights reserved.

引用

页码：305 / 314

页数：10

共 47 条

[1] RAMAN-SPECTROSCOPY OF POTASSIUM TITANATES - THEIR SYNTHESIS, HYDROLYTIC REACTIONS, AND THERMAL-STABILITY [J].