基于第一性原理的LSCF表面吸附PdO理论研究
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- 英文论文题名：A first principles study about PdO absorption on the surface of LSCF
- 论文作者：魏明锐 ; 李海召 ; 郭冠伦
- 英文论文作者：Mingrui Wei ; Haizhao Li ; Guanlun Guo ; Hubei Key Laboratory of Advanced Technology for Automotive Components ; Wuhan University of Technology ; Hubei Collaborative Innovation Center for Automotive Components Technology ; Wuhan University of Technology
- 年：2016
- 作者机构：武汉理工大学现代汽车零部件技术湖北省重点实验室;武汉理工大学汽车零部件技术湖北省协同创新中心;
- 论文关键词：第一性原理 ; PdO吸附 ; LSCF
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第二十九分会：电化学材料
- 语种：中文
- 分类号：O647.31
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第二十九分会 ; 电化学材料
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：328k
- 原文格式：D
- 会议级别：全国
摘要
Pd金属覆盖中温阴极材料La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_3(LSCF)可提高氧在LSCF表面的还原。通过含Pd溶液浸渍LSCF,室温下Pd元素以PdO的形式存在。为研究氧化钯(PdO)分子在掺杂钙钛矿结构材料LSCF表面吸附的最可能位置,本研究采用MS软件中的CASTEP模块对其进行第一性原理探究,为进一步探究Pd与PdO之间转变机理奠定基础。计算结果表明:PdO分子在LSCF最稳定的(001)表面吸附时(如图1所示),PdO分子水平姿态吸附较垂直姿态吸附稳定;吸附模型最稳定的两种为模型A5(AO位点上吸附模型)与B8(BO_2位点上吸附模型),吸附能分别约为3.87eV与6.15eV;BO_2吸附位点PdO吸附后,总态密度向低能区转移,AO位点的总态密度在吸附前后未向低或高能区转移。这表明PdO吸附后BO_2更加稳定,而AO面稳定性保持不变。
Pd coating on LSCF(intermediate-temperature cathode material) can improve oxygen reduction on the surface of LSCF. However, the Pd species exists as PdO at room temperature. The optimal position of the PdO molecular absorption on the surface of LSCF was studied by CASTEP with first principles to build a foundation for studying the transformation mechanism between Pd and PdO in the future. The results showed that it's more stable when the Pd O molecular was absorbed with a parallel orientation on the most stable surface((0 0 1) surface) of LSCF than it's with a perpendicular orientation(Figure 1). The most stable absorption models were A5(PdO absorption on AO site) and B8(PdO absorption on BO_2 site), whose absorption energies(Ea) were 3.87 e V and 6.15 eV, respectively. Compared to the density of states(DOS) before PdO absorption on LSCF, DOS of A5 moved to the lower energy side while this of B8 kept unchangeable after PdO absorption, which indicates that BO_2 becomes more stable while AO stays unchangeable.
Pd coating on LSCF(intermediate-temperature cathode material) can improve oxygen reduction on the surface of LSCF. However, the Pd species exists as PdO at room temperature. The optimal position of the PdO molecular absorption on the surface of LSCF was studied by CASTEP with first principles to build a foundation for studying the transformation mechanism between Pd and PdO in the future. The results showed that it's more stable when the Pd O molecular was absorbed with a parallel orientation on the most stable surface((0 0 1) surface) of LSCF than it's with a perpendicular orientation(Figure 1). The most stable absorption models were A5(PdO absorption on AO site) and B8(PdO absorption on BO_2 site), whose absorption energies(Ea) were 3.87 e V and 6.15 eV, respectively. Compared to the density of states(DOS) before PdO absorption on LSCF, DOS of A5 moved to the lower energy side while this of B8 kept unchangeable after PdO absorption, which indicates that BO_2 becomes more stable while AO stays unchangeable.
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