Adsorption Preference Determines Segregation Direction: A Shortcut to More Realistic Surface Models of Alloy Catalysts
Adsorption Preference Determines Segregation Direction: A Shortcut to More Realistic Surface Models of Alloy Catalysts
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DOI：
10.1021/acscatal.9b00499
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发表时间：
2019-04
期刊：
影响因子：
12.9
通讯作者：
Sihang Liu;Zhijian Zhao;Chengsheng Yang;Shenjun Zha;Konstantin M. Neyman;F. Studt;Jinlong Gong
中科院分区：
文献类型：
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作者：
Sihang Liu;Zhijian Zhao;Chengsheng Yang;Shenjun Zha;Konstantin M. Neyman;F. Studt;Jinlong Gong
对活性中心的正确描述是反应机理研究和催化剂筛选的前提。在许多情况下，高对称性和理想有序的晶面被用来表示反应中心。然而，反应引起的表面偏析和重组削弱了简单地采用所建议的最稳定表面的合理性。建立了偏析能与吸附择优之间的标度关系，以较低的计算代价快速预测了双金属表面的偏析，这有助于建立更准确的活性中心，特别是对于偏析倾向的合金。基于这种方法，对典型的双金属合金CoCu的两个表面模型进行了计算，探讨了典型加氢反应的机理。我们的平行实验表明，CoCu催化剂的反应活性由表面Co/Cu组成决定，反映了单一且仅有的表面模式的局限性。
A correct description of active sites is a precondition toward reaction mechanism study and catalyst screening. In many cases, high-symmetry and ideally ordered crystalline surfaces are used to represent the reactive sites. However, reaction-induced surface segregation and restructuring weaken the rationality of simply employing the suggested most stable surfaces. This paper describes establishment of the scaling relation between segregation energy and adsorption preference for a fast prediction of segregation over bimetallic surfaces with low computational cost, which helps the construction of more accurate active sites, especially for segregation-prone alloys. Based on this methodology, mechanisms of representative hydrogenation reactions are computationally explored on two surface models of a typical bimetallic alloy, CoCu. Our experiments performed in parallel demonstrate the reactivity of CoCu catalyst to be determined by surface Co/Cu composition, reflecting the limitation of one-and-only surface mo...