Direct templating assembly route for the preparation of highly-dispersed vanadia species encapsulated in mesoporous MCM-41 channel
Direct templating assembly route for the preparation of highly-dispersed vanadia species encapsulated in mesoporous MCM-41 channel
复制标题
制备封装在介孔 MCM-41 通道中的高度分散氧化钒物种的直接模板组装路线
DOI：
10.1039/c5ra12363a
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发表时间：
2015-08
期刊：
影响因子：
3.9
通讯作者：
Yan Kong
中科院分区：
文献类型：
--
作者：
Fu Yang;Shuying Gao;Cuirong Xiong;Saifu Long;Xiaoming Li;Tao Xi;Yan Kong
了解活性中心的性质，包括在载体表面上的数量和分散度，对于提高催化活性至关重要。本研究采用直接模板组装法（S+ L-M +I-），在介孔MCM-41孔道内直接制备了高分散、可控量的氧化钒物种。该方法基于阳离子表面活性剂（CTA+，S+）、螯合剂（柠檬酸根离子，L−）、钒氧离子（VO 2+，M+）和硅酸盐低聚物（I−）通过静电和螯合相互作用的自组装。首先，柠檬酸根离子通过静电相互作用吸附在CTA+胶束的表面上，并且钒氧离子随后通过与柠檬酸根离子螯合而锚定在其表面上以形成金属胶束。最后，将硅酸盐沉积在金属胶束上以获得目标产物。采用XRD、N2吸附、SEM、TEM、UV-vis、XPS、FT-IR、ICP、H2-TPR等技术对样品的结构进行了表征，重点研究了钒物种在介孔氧化硅上的氧化态和表面分布。此外，与合成后的样品相比，使用苯的羟基化作为探针反应获得的样品表现出上级催化活性。
Understanding the nature of active sites, including the number and dispersion on the surface of a support, is essential to improve the catalytic activity. In this study, highly-dispersed and controllable quantities of vanadia species within the channels of mesoporous MCM-41 were directly prepared by a direct templating assembly method (S+L−M+I−). This method was based on the self-assembly of cationic surfactants (CTA+, S+), chelating agents (citrate ions, L−), vanadyl ions (VO2+, M+) and silicate oligomers (I−) via electrostatic and chelating interaction. First, the citrate ions were absorbed on the CTA+ micelles' surface by electrostatic interaction, and the vanadyl ions were subsequently anchored on their surface by chelating with citrate ions to form metallomicelles. Finally, the silicates were deposited on the metallomicelles to obtain the targeted product. The structures of the samples especially the oxidation state and surface distribution of vanadium species on the mesoporous silica were efficiently characterized with different techniques, including XRD, N2 adsorption, SEM, TEM, UV-vis, XPS, FT-IR, ICP, and H2-TPR. Furthermore, the samples obtained using hydroxylation of benzene as a probe reaction exhibited superior catalytic activities when compared with the post-synthesized sample.
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DOI：
10.1002/chin.201227258
发表时间：
2012-07
期刊：
ChemInform
影响因子：
--
作者：
Zongxi Li;J. C. Barnes;Aleksandr Bosoy;J. Stoddart;J. Zink
通讯作者：
Zongxi Li;J. C. Barnes;Aleksandr Bosoy;J. Stoddart;J. Zink
影响因子：
4
作者：
Wachs, Israel E.
通讯作者：
Wachs, Israel E.
影响因子：
5.2
作者：
E. Caponetti;A. Minoja;M. Saladino;A. Spinella
通讯作者：
E. Caponetti;A. Minoja;M. Saladino;A. Spinella
影响因子：
5.5
作者：
N. Melosh;P. M. Lipic;F. Bates;F. Wudl;G. Stucky;G. Fredrickson;B. Chmelka
通讯作者：
N. Melosh;P. M. Lipic;F. Bates;F. Wudl;G. Stucky;G. Fredrickson;B. Chmelka
影响因子：
7.3
作者：
B. Solsona;T. Blasco;J. Nieto;M. L. Peña;F. Rey;A. Vidal-Moya
通讯作者：
B. Solsona;T. Blasco;J. Nieto;M. L. Peña;F. Rey;A. Vidal-Moya