Mononuclear gold species anchored on TS-1 framework as catalyst precursor for selective epoxidation of propylene
Mononuclear gold species anchored on TS-1 framework as catalyst precursor for selective epoxidation of propylene
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DOI：
10.1016/j.jcat.2018.09.002
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发表时间：
2018-11-01
影响因子：
7.3
通讯作者：
Tsang, S. C. Edman
中科院分区：
文献类型：
--
作者：
Ayvali, Tugce;Ye, Lin;Tsang, S. C. Edman
金在载体上的沉积可以产生催化活性形式的金以及观众，但以前对活性固定前体的性质的了解很差。利用同步辐射X射线粉末衍射(SXRD)和X射线吸收光谱(XAS)技术，合成了一种原子分散在TS-1分子筛内表面的金物种K+Au(OH)(2)Na+(O-f)(3)(“f”表示分子式中的骨架原子)。研究发现，碱性离子的选择对原子前驱体的成核和稳定起着至关重要的作用。这些锚定的单一Au在H-2中受控还原后可以形成均匀的金团簇，与含有孤立钛中心的TS-1表面直接接触：由于协同作用，它们的界面对丙烯在H-2/O-2中的环氧化反应表现出良好的专一性和稳定性。(C)2018 Elsevier Inc.保留所有权利。
Deposition of gold on supports can produce catalytically active forms of gold as well as spectators, but previous understanding of the nature of active immobilized precursors is poor. By using synchrotron X-ray powder diffraction (SXRD) and X-ray absorption spectroscopy (XAS) techniques, we report a novel synthesis and structural elucidation of atomically dispersed gold species anchored to the internal surface of TS-1 as K+Au(OH)(2)Na+(O-f)(3) ("f" signifies the framework atoms of TS-1 in the formula.). It is found that the choice of alkali ions plays a crucial role in nucleation and stabilization of the atomic precursor. These anchored single Au upon controlled reduction in H-2 can form uniform gold clusters in direct contact with the TS-1 surface containing isolated Ti sites: their interface exhibits excellent specificity and stability towards epoxidation of propylene in H-2/O-2 due to synergetic effect. (C) 2018 Elsevier Inc. All rights reserved.