摘要本文基于密度泛函理论系统研究无缺陷以及带有S缺陷的单层二硫化钼(MoS2)材料对Con(n=1-4)团簇的吸附机制,得到了Con团簇在二硫化钼(MoS2)表面形成的Con@MoS2、Con@SV-MoS2体系的稳定构型,通过结合能以及吸附能的计算得到Con(n=1-3)可以稳定吸附在完美MoS2材料表面不会形成团聚,而Con吸附于带有S缺陷的MoS2体系则会容易团聚。接着我们对CO、O2、CO2气体吸附于Con@MoS2、 Con@SV-MoS2表面进行研究,发现Co、Co2吸附在MoS2表面形成的体系可以用于一氧化碳CO催化,主要表现为:(1)CO、O2在这两种体系的吸附能EO2大于或与ECO的值近似,防止了CO对材料表面的毒化;(2)通过对键长的分析,发现一氧化碳中C-O键与气相时的键长是非常接近的,而氧气的O-O键被拉长,说明O2分子与表面存在强烈的相互作用,有利于CO的氧化;(3)CO2气体吸附在表面属于物理吸附,在CO被氧化后生成的CO2可以迅速脱离表面,不会影响其他CO分子的氧化过程。因此我们预言过渡金属Co吸附于无缺陷或带有S缺陷的MoS2体系可以用于一氧化碳的催化,其中Co2@MoS2是一个最可能成为CO氧化的良好催化剂。87511
毕业论文关键词 密度泛函理论 二硫化钼 Co团簇 CO氧化
毕业设计说明书外文摘要
Title The theoretical study of Cobalt clusters adsorbing on Monolayer MoS2
Abstract Using the density functional theory (DFT), we study the mechanism that Con (n = 1-4) clusters adsorption on single-layer molybdenum disulfide (MoS2) system with the S defect and without defect。 First, we find the steady configuration of Co@MoS2 and Con@SV-MoS2 where Con (n = 1-3) clusters form on the two-dimensional material。 We calculate the adsorption energy and binding energy to certify that they can’t assemble。 In additional, we find that Con adsorbing on the materials with the S defect could assemble。 Second, We study that the adsorption that CO, O2 and CO2 adsorb on the surface of Con@MoS2、 Con@SV-MoS2。 The results show that Co@MoS2 and Co2@MoS2 can be candidates for the catalyst for CO oxidation。 The reasons are following: (1) The adsorption energy of O2 is greater than the CO or similar to CO, which show that Materials can avoid the poisoning of CO。 (2) With the analyses of bond length, we find that the bond length of the CO is similar to its gaseous phase and the bond length of O2 is stretched。 These results show that O2 has the interactions with the materials, which is benefit of the oxidation of CO。 (3) The adsorption of CO2 on the surface is physical adsorption, it will not have the influence of the oxidation of CO。 Therefore, we can predict that the Co transition metal adsorbing on the MoS2 with S defect and without defect can act as catalyst for the CO oxidation, and the Co2@MoS2 will be a great candidate。
Keywords Molybdenum disulfide Cobalt clusters Density Functional Theory Carbon monoxide
目 次
1 引言(或绪论) 1
2 计算方法 3
2。1 密度泛函理论(DFT)简介 3
2。2 基于密度泛函理论的计算 4
2。3 Materials Studio软件简介 7
3 计算过程及结果分析 10
3。1计算过程 10
3。2结果分析 10
结 论 17
致 谢 18
参 考 文 献 19