Efficient and clean epoxidation of methyl oleate to epoxidized methyl oleate catalyzed by external surface of TS-1 supported molybdenum catalysts
Efficient and clean epoxidation of methyl oleate to epoxidized methyl oleate catalyzed by external surface of TS-1 supported molybdenum catalysts
复制标题
TS-1负载钼催化剂外表面催化油酸甲酯高效清洁环氧化成环氧化油酸甲酯
DOI：
10.1016/j.micromeso.2022.111731
复制
发表时间：
2022-01
影响因子：
5.2
通讯作者：
Guoqiang Wu
中科院分区：
文献类型：
--
作者：
Xiu Gao;Yingqi Zhang;Yanping Hong;Beining Luo;Xianzai Yan;Guoqiang Wu
油酸甲酯（MO）大分子无法进入常规钛硅沸石-1（TS-1）沸石的微孔通道，导致MO环氧化催化活性较低。在此，通过蒸汽辅助结晶成功合成了具有大表面积的小尺寸TS-1（TS-1-s）沸石，然后制备了新型封闭型TS-1-s负载钼（Mo/TS-1-bs）催化剂，用于用清洁的H2O2高效环氧化MO以生产环氧化油酸甲酯（EMO）。各种表征结果表明，引入的Mo物种高度分散在TS-1-s的外表面上，而没有破坏MFI型沸石和四面体骨架钛（Ti4+）的结构。有趣的是，大量Mo6+物质表现出一定的环氧化活性，这是由于Mo物质与H2O2结合生成亲电子氢过氧化钼（Mo–OOH）物质，它可以很容易地与MO分子吸附并发生反应。此外，Mo物种还通过O原子与Ti4+物种配位，导致H2O2容易攻击Ti-O键，并且易于形成活性中间体。因此，与传统的TS-1相比，Mo/TS-1-bs在环氧化反应中表现出更高的催化活性。然而，由于路易斯酸的形成，Mo/TS-1-bs催化剂的酸性随着Mo负载量的增加而增加，从而导致副反应和EMO选择性降低。因此，开发了高效、无腐蚀、绿色的MO环氧化催化体系，并证明了Mo物种活性的提高和酸的影响。
Methyl oleate (MO) macromolecules are unable to access the microporous channel of conventional titanium silicalite-1 (TS-1) zeolite, which leads to the low catalytic activity of epoxidation of MO. Herein, the small-size TS-1 (TS-1-s) zeolite with a large surface area was synthesized successfully through steam-assisted crystallization, and then a novel blocked TS-1-s supported molybdenum (Mo/TS-1-bs) catalysts were prepared for efficient epoxidation of MO with clean H2O2to produce epoxidized methyl oleate (EMO). Various characterization results show the introduced Mo species are highly dispersed on the outer surface of TS-1-s without destroying the structure of the MFI type zeolite and the tetrahedral framework titanium (Ti4+). Interestingly, a large number of Mo6+species exhibit certain epoxidation activity attributing to the generating of electrophilic molybdenum hydroperoxide (Mo–OOH) speciesviaMo species combined with H2O2, which could adsorb and react easily with MO molecules. Furthermore, the Mo species are also coordinated with Ti4+species through the O atom resulting in the facile attack of the Ti–O bonds by H2O2and easy to form an active intermediate. Therefore, compared with the conventional TS-1, the Mo/TS-1-bs shows higher catalytic activity in the epoxidation reaction. However, the acidity of Mo/TS-1-bs catalysts increases with increasing the Mo-loading owing to the formation of Lewis acid, which leads to the side reactions and the decrease of EMO selectivity. As a consequence, the efficient, non-corrosive and green catalytic system for epoxidation of MO was developed, and the activity improvement of Mo species and the influence of acid were also demonstrated.
登录
查看更多内容
影响因子：
5.1
作者：
Vanessa A. Pereira;A. Fonseca;C. Costa;A. Ramalho;J. Coelho;A. Serra
通讯作者：
Vanessa A. Pereira;A. Fonseca;C. Costa;A. Ramalho;J. Coelho;A. Serra
影响因子：
4.7
作者：
Perez-Sena WY;Wärnå J;Eränen K;Tolvanen P;Estel L;Leveneur S;Salmi T
通讯作者：
Salmi T
DOI：
10.1016/j.jmrt.2021.10.102
发表时间：
2021-10
期刊：
Journal of Materials Research and Technology
影响因子：
--
作者：
Baoxian Su;Binbin Wang;L. Luo;Liang Wang;Yan-Qing Su;Yan-Jin Xu;Fuxin Wang;Baoshuai Han
通讯作者：
Baoxian Su;Binbin Wang;L. Luo;Liang Wang;Yan-Qing Su;Yan-Jin Xu;Fuxin Wang;Baoshuai Han
影响因子：
15.1
作者：
Zhang Junliang;C. Peng;Huiyan Yan;Zhijie Wu;T. Dou
通讯作者：
Zhang Junliang;C. Peng;Huiyan Yan;Zhijie Wu;T. Dou
影响因子：
8.4
作者：
M. Yao;Yao Huang;Xun Niu;H. Pan
通讯作者：
M. Yao;Yao Huang;Xun Niu;H. Pan