从头算分子动力学研究H_(2)在缺陷石墨烯负载的Cu_(19)团簇上解离吸附  

Ab Initio Molecular Dynamics Study of Dissociative Adsorption of H_(2) on Defective Graphene-Supported Cu_(19) Cluster

作　　者：刘乃贵 高得鲁 王敦友[1] Naigui Liu;Delu Gao;Dunyou Wang(College of Physics and Electronics,Shandong Normal University,Jinan 250014,China)

机构地区：[1]山东师范大学物理与电子科学学院,济南250014

出　　处：《Chinese Journal of Chemical Physics》2023年第6期747-754,I0057,共9页化学物理学报（英文）

基　　金：supported by the National Natural Sci-ence Foundation of China(No.11774206);Taishan Scholarship fund from Shandong Province.

摘　　要：本文运用从头算分子动力学方法研究了H_(2)在Cu_(19)团簇和缺陷石墨烯负载Cu_(19)团簇上的解离吸附.分子水平上的动力学轨迹表明,氢气在Cu_(19)上解离吸附的最佳位点是桥位-空位,两个氢原子吸附在Cu原子两边的桥位和空位上,吸附能为-0.74 eV.在缺陷石墨烯负载的Cu_(19)团簇上,两个氢原子的最佳吸附位置是吸附在两个空位上,吸附能为-1.27 eV.总的来说,缺陷石墨烯负载Cu_(19)团簇上的平均吸附能为-1.07 eV,比Cu_(19)团簇上的-0.58 eV多约84%,这表明缺陷石墨烯负载Cu_(19)簇上对于氢气的解离吸附能力大大增强.d带中心向费米能级靠近解释了为什么缺陷石墨烯负载Cu_(19)团簇吸附能力更强.积分晶体轨道哈密顿布居分析表明,与Cu_(19)团簇相比,在缺陷石墨烯支持的Cu_(19)簇上,氢原子与其键合的Cu原子之间更强的键相互作用导致了更大的吸附能.The dissociative adsorption of H_(2) on Cu_(19) and defective graphene-supported Cu_(19) clusters(Cu_(19)G)are investigated using ab initio molecular dynamics.The molecular-level trajectories show that,on Cu_(19),the preferred adsorption site is the bridge-hollow site,where the two H atoms are adsorbed at the bridge and hollow sites beside a Cu atom,with an adsorption energy of−0.74 eV.In contrast,on the defective graphene-supported Cu_(19) cluster,the favorite adsorption site is located where the two H atoms are adsorbed at hollow-hollow sites with an adsorption energy of−1.27 eV.In general,the average adsorption energy on the defective graphene-supported Cu_(19) cluster is−1.07 eV,which is about 84%larger than that of−0.58 eV on the Cu_(19) cluster.This indicates that the adsorption capacity is greatly enhanced for the dissociative adsorption of H_(2) on the defective graphene-supported Cu_(19) cluster.The d-band center shifts to the Fermi level,illustrating the enhanced adsorption capacity on the defective graphene-supported Cu_(19) cluster.The integrated crystal orbital Hamilton population analysis reveals that stronger bond interactions between hydrogen atoms with their bonded Cu atoms lead to much larger adsorption energies on the defective graphene-supported Cu_(19) cluster compared to the Cu_(19) cluster.

关 键 词：氢气的解离吸附 从头算分子动力学 吸附能 密度泛函理论 

分 类 号：O647.3[理学—物理化学]