Initial hydrogenations of pyridine on MoP(001): A density functional study.
writer：Y. Li, W. Y. Guo, H. Y. Zhu, L. M. Zhao, S. R. Li, D. L. Fu, X. Q. Lu, H. H. Shan.
keywords：Initial hydrogenations, MoP(001)
source：期刊
specific source：Langmuir
Issue time：2012年
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 η5(N,Cα,Cβ,Cβ,Cα) configuration of the side-on mode facilitates the hydrogenation of pyridine. The optimal hydrogenation path of pyridine with surface hydrogen atoms in the Langmuir–Hinshelwood mechanism is the formation of 3-monohydropyridine, followed by producing 3,5-dihydropyridine, in which the two-step hydrogenations take place on the Cβ 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.