Initial Hydrogenations of Pyridine on MoP(001): A Density Functional Study

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• 作者：Yang Li ; Wenyue Guo ; Houyu Zhu ; Lianming Zhao ; Ming Li ; Shaoren Li ; Dianling Fu ; Xiaoqing Lu ; Honghong Shan
• 刊名：Langmuir
• 出版年：2012
• 出版时间：February 14, 2012
• 年：2012
• 卷：28
• 期：6
• 页码：3129-3137
• 全文大小：504K
• 年卷期：v.28,no.6(February 14, 2012)
• ISSN：1520-5827

文摘

The initial hydrogenations of pyridine on MoP(001) with various hydrogen species are studied using self-consistent periodic density functional theory (DFT). The possible surface hydrogen species are examined by studying interaction of H₂ and H₂S with the surface, and the results suggest that the rational hydrogen source for pyridine hydrogenations should be surface hydrogen atoms, followed by adsorbed H₂S and SH. On MoP(001), pyridine has two types of adsorption modes, i.e., side-on and end-on; and the most stable 畏⁵(N,C^伪,C^尾,C^尾,C^伪) configuration of the side-on mode facilitates the hydrogenation of pyridine. The optimal hydrogenation path of pyridine with surface hydrogen atoms in the Langmuir鈥揌inshelwood mechanism is the formation of 3-monohydropyridine, followed by producing 3,5-dihydropyridine, in which the two-step hydrogenations take place on the C^尾 atoms. When adsorbed H₂S is considered as the source of hydrogen, slightly higher hydrogenation barriers are always involved, while the energy barriers for hydrogenations involving adsorbed SH are much lower. However, the hydrogenation of pyridine should be suppressed by the adsorption of H₂S, and the promotion effect of adsorbed SH is limited.