Design of Effective Catalysts for Selective Alkyne Hydrogenation by Doping of Ceria with a Single-Atom Promotor
Design of Effective Catalysts for Selective Alkyne Hydrogenation by Doping of Ceria with a Single-Atom Promotor
复制标题
单原子促进剂掺杂二氧化铈选择性炔烃选择性加氢的有效催化剂设计
DOI：
10.1021/jacs.8b07789
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发表时间：
2018-10-10
影响因子：
15
通讯作者：
Datye, Abhaya
中科院分区：
文献类型：
--
作者：
Riley, Christopher;Zhou, Shulan;Datye, Abhaya
自从发现二氧化铈是一种具有选择性加氢活性的催化剂以来，关于其催化机理一直存在争议。在这项工作中，我们提出，基于密度泛函理论（DFT）的调查，涉及的H2-在CeO 2（111）的氧空位的异裂解离的机制，由空间上分离的O和Ce网站组成的阻挫刘易斯对促进。所得到的O-H和Ce-H物种有效地催化乙炔的氢化，避免了先前提出的机制中的C2 H3 * 中间体的过度稳定。在我们的机制的基础上，我们提出了掺杂的二氧化铈作为一种手段，以创造氧空位的Ni。有趣的是，Ni掺杂剂不直接参与催化反应，而是作为单原子促进剂。实验研究证实了Ni掺杂氧化铈催化剂的设计原则，并显示出更高的乙炔选择加氢活性。DFT计算和实验结果的结合为进一步开发基于地球资源丰富的材料的选择性加氢催化剂提供了基础。
Since the discovery that ceria is an active catalyst for selective hydrogenation of alkynes, there has been much debate on the catalytic mechanism. In this work, we propose, based on density functional theory (DFT) investigations, a mechanism that involves the heterolytic dissociation of H-2 at oxygen vacancies of CeO2(111), facilitated by frustrated Lewis pairs consisting of spatially separated O and Ce sites. The resulting O-H and Ce-H species effectively catalyze the hydrogenation of acetylene, avoiding the overstabilization of the C2H3* intermediate in a previously proposed mechanism. On the basis of our mechanism, we propose the doping of ceria by Ni as a means to create oxygen vacancies. Interestingly, the Ni dopant is not directly involved in the catalytic reaction, but serves as a single-atom promoter. Experimental studies confirm the design principles and demonstrate much higher activity for Ni-doped ceria in selective hydrogenation of acetylene. The combined results from DFT calculations and experiment provide a basis to further develop selective hydrogenation catalysts based on earth-abundant materials.