First-Principles Modeling of Oxygen Adsorption on Ag-Doped LaMnO3 (001) Surface
Date
2020
Authors
Abuova, A. U.
Mastrikov, Yuri A.
Kotomin, Eugene A.
Piskunov, Sergei
Inerbaev, T. M.
Akilbekov, A. T.
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Nature Switzerland AG
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.
Description
This study was partly financed by the State Education Development Agency of the Republic of Latvia via the Latvian State Scholarship (A.A.) and Latvia-Ukraine Project (Grant LV-UA/2018/2 to E.K.). The work of T.I. is performed under the state assignment of IGM SB RAS. Also, this research was partly supported by the Ministry of Education and Science of the Republic of Kazakhstan in the framework of the scientific and technology Program BR05236795 ‘‘Development of Hydrogen Energy Technologies in the Republic of Kazakhstan’’. The authors thank M. Sokolov for technical assistance and valuable suggestions.
Keywords
Research Subject Categories::NATURAL SCIENCES:Physics , Solid oxide fuel cells , LaMnO3 , oxygen adsorption , Ag catalyst , ab initio calculations