Abstract

The density functional theory (DFT) method has been used to calculate oxygen adsorption on the Ag-doped MnO₂- and LaO-terminated (001) LaMnO₃ surfaces. The catalytic effect of Ag doping is revealed by comparison of the adsorption energies, electron charge redistribution, and interatomic distances for the doped and undoped surfaces. Adsorption of Ag on the MnO₂-terminated surface increases the adsorption energy for both atomic and molecular oxygen. This increases the oxygen surface concentrations and could improve the cathode efficiency of fuel cells. The opposite effect takes place at the LaO-terminated surface. Due to the large adsorption energies, adsorbed oxygen atoms are immobile and the oxygen reduction reaction rate is controlled by the concentration and mobility of oxygen vacancies.

中文翻译：

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掺Ag的LaMnO 3（001）表面上氧吸附的第一性原理建模

摘要

密度泛函理论（DFT）方法已用于计算氧在Ag掺杂的MnO _2-和LaO终止的（001）LaMnO ₃表面上的吸附。通过比较掺杂和未掺杂表面的吸附能，电子电荷再分布和原子间距离，可以看出Ag掺杂的催化作用。Ag在MnO ₂上的吸附末端的表面增加了原子氧和分子氧的吸附能。这增加了氧气表面浓度，并可以提高燃料电池的阴极效率。相反的效果发生在LaO端接的表面。由于大的吸附能，吸附的氧原子是不动的，并且氧还原反应的速率受氧空位的浓度和迁移率控制。