1. Theoretical study on the migration of NOx to the Pt in proximity of Ba on γ-Al2O3(100).
- Author
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Li, Zhijun, Li, Shilong, Zhang, Shijie, Lv, Heyin, and Yang, Miansong
- Subjects
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ACTIVATION energy , *DENSITY functional theory , *PRECIOUS metals , *ELECTRONIC structure , *BARIUM , *ALKALINE earth metals - Abstract
[Display omitted] • Development of a slab model for alumina-loaded Pt/Ba, considering the effects of both sites simultaneously. • The species exchange process of nitrogen-containing species between proximate Ba and Pt sites is different from the conventional view. • A good linear relationship between NOx adsorption energy and its migration energy barrier. • Detailed electronic structure analysis reveals the reason in essence. Based on density functional theory (DFT) calculations, NO x tends to migrate from Ba to Pt sites within the Lean NO x trap (LNT), rather than reacting at Pt sites before migrating to Ba sites for storage as traditionally believed. Compared with NO and N 2 O, NO 2 has the highest migration energy barrier, and there is a good linear relationship between the adsorption energy of NO x and its migration energy barrier. Furthermore, the essential cause of the above phenomenon is revealed. This study contributes to the exchange of NO x between noble metal catalytic sites and alkaline earth metal storage sites within the LNT. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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