Interaction of Pd single atoms with different CeO2 crystal planes: A first-principles study
Interaction of Pd single atoms with different CeO2 crystal planes: A first-principles study
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Pd 单原子与不同 CeO2 晶面的相互作用：第一性原理研究
DOI：
10.1016/j.apsusc.2017.10.134
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发表时间：
2018
影响因子：
6.7
通讯作者：
Cheng Sujun
中科院分区：
文献类型：
--
作者：
He Bingling;Wang Jinlong;Ma Dongwei;Tian Zhixue;Jiang Lijuan;Xu Yan;Cheng Sujun
用第一性原理方法研究了Pd原子在CeO2表面(111)、(110)和(100)表面上的吸附。结果表明，根据计算的吸附能，Pd与CeO2三个表面的相互作用强度顺序为(100)×(110)××(111)。有趣的是，Pd吸附引起的Ce离子表面电子局域化对其吸附稳定性的影响在(110)面上比在(111)和(100)面上更为显著。Pd~(2+)、Pd~(δ+(δ)和Pd~(1+)在CeO_2(111)面上可能存在形式氧化态，Pd~(2+)和Pd~(1+)可能在CeO_2(100)面上共存。然而，在合适的条件下，CeO2(110)表面可以被Pd2+离子覆盖。目前的理论结果清楚地表明，Pd与CeO2纳米晶之间的相互作用很大程度上取决于CeO2的晶面。我们的研究将对CeO_2晶面对CeO_2负载Pd催化剂的物化和催化性能的影响提供有益的启示。
The adsorption of single Pd atoms on the various CeO2surfaces, including (111), (110), and (100), has been studied based on the first-principles calculations. It is found that, according to the calculated adsorption energy, interaction strength between Pd and the three CeO2surfaces follows the order of (100) > (110) > (111). Interestingly, the effect of the electron localization on the surface Ce ions due to the Pd adsorption on its adsorption stability is more significant for the (110) surface than that for the (111) and (100) surfaces. We also find that the formal oxidation states of Pd0, Pdδ+(δ < 1) and Pd1+may appear on the CeO2(111) surface, and Pdδ+(δ < 1) and Pd1+could coexist on the CeO2(100) surfaces. However, under suitable conditions the CeO2(110) surface may be covered with Pd2+ions. Present theoretical results clearly suggest that the interaction between Pd and CeO2nanocrystals significantly depends on the crystal planes of CeO2. It is expected that our study will give useful insights into the effect of CeO2crystal plane on the physicochemical and catalytic properties of CeO2supported Pd catalyst.