氧在La/SrMnO3(001)表面吸附、解离和表面扩散的第一性原理  

First principle of adsorption,dissociation and diffusion of oxygen on La/SrMnO_3(001) surface

作　　者：路文江[1,2] 国星[1] 冯煜东[3] 吴春华[3] 许旻[3] 汤富领[1,2] 

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050 [2]兰州理工大学甘肃省有色金属新材料重点实验室,甘肃兰州730050 [3]兰州物理研究所表面工程技术重点实验室,甘肃兰州730000

出　　处：《兰州理工大学学报》2013年第1期161-166,共6页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(10964003,11164014);教育部博士点基金(20096201120002);中国博士后科学基金(20100470886,201104345);兰州物理研究所表面工程技术重点实验室开放基金(BM201101,BM201102)的支持

摘　　要：采用基于密度泛函的第一性原理的方法,同时结合Nudged Elastic Band方法,系统研究O原子和O2分子在La/SrMnO3(001)表面的吸附过程。给出O2分子在MnO2、LaO和SrO外表面的解离路径和势垒;研究O原子在三种表面的扩散过程,计算出各扩散路径的势垒和最稳定的吸附位置的基本情况。在此基础上,通过比较解离、扩散和放氧环节的激活能数据,提出O2的解离和表面放氧过程均为速率控制步骤。进一步为La/SrMnO3作为固体阴极材料时决定性能的第一步吸附反应提供理论数据的支持.Employing the first principle and method with density functional as its basis and,in the same time,incorporating the Nudged Elastic Band method,the adsorption process of atomic and molecular oxygen on La/SrMnO3（001）surface was systematically investigated.The dissociation path and potential barrier of O2 molecules on the outer surface of MnO2,LaO and SrO were given.The diffusion process of the O-atom on these three surfaces was investigated and the basic situation of potential barrier and the most stable adsorption position were computed.On this basis and by means of comparing the values of the activation energies during the process of dissociation,diffusion,and desorption,it was presented that the dissociation and surface release of O2 were rate controlling procedure,providing further a theoretical data support for first adsorptive reaction on the surface of La/SrMnO3 as solid cathode material to determine its performance.

关 键 词：第一性原理计算 吸附能 扩散 势垒 解离 

分 类 号：O482.54[一般工业技术—材料科学与工程]