几种含氮化合物在MoS_2晶面的吸附研究

The adsorption of nitrogen compounds on MoS_2

油品中的含氮化合物易使加氢脱硫催化剂中毒,对脱硫反应有很强的抑制作用,因此,研究含氮化合物在加氢脱硫催化剂上的吸附行为,对了解其对加氢脱硫反应的作用机理有重要意义。本文利用基于密度泛函理论(DFT)的Vienna ab-inito simulation package(VASP)程序包计算了碱性含氮化合物(喹啉、吡啶、苯胺)、非碱性含氮化合物(吲哚和咔唑)在硫化钼(MoS_2)晶体表面吸附形式和吸附能。研究结果表明:5种含氮化合物的平行吸附能大于倾斜和垂直吸附能,它们最可能以平行吸附的形式自发的吸附在MoS_2晶面上。碱性含氮化合物中喹啉的吸附能最大、吡啶其次、苯胺最小;非碱性含氮化合物咔唑的吸附能大于吲哚;咔唑的吸附能略大于喹啉。

Nitrogen compounds in petroleum products usually have poisoning effect on hydrodesulfurization catalyst and inhibition effect on hydrodesulfurizatiun reaction. On this account, the research of adsorption behavior of nitrogen compounds on hydrodesulfurization catalyst will contribute to understanding the inhibitory mechanism for the hydrodesulfurization reaction. The adsorption behavior and adsorption energy of basic nitrogen compounds （quinolone, pyridine and aniline） and non-basic nitrogen compounds （indole and carbazole） on the molybdenum sulfide cluster surface are studied by the VASP package in Density Functional Theory （DFT）. The result shows that when those nitrogen compounds are parallel adsorb on the molybdenum sulfide cluster surface, the adsorption energy is greater than that of nitrogen compounds, which are oblique or vertical adsorption behavior. The adsorption energy of quinolone is the largest, secondly, is the pyridine and aniline reaches the lowest values among those basic nitrogen compounds. The adsorption energy of carbazole is greater than that of indole between non-basic nitrogen compounds. The adsorption energy of carbazole is slightly larger than that of quinolone.