Bai, Zhongze;
Luo, Kai H;
(2025)
Mechanistic study of Hg⁰ oxidation over LaMnO₃ oxygen carrier during chemical looping combustion.
Chemical Engineering Journal
, 520
, Article 166154. 10.1016/j.cej.2025.166154.
(In press).
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Abstract
LaMnO₃, known for its high thermal stability, redox activity and cost-effectiveness, is a promising material for coal chemical looping combustion (CLC). Density functional theory (DFT) calculations are carried out to investigate the catalytic mechanisms of Hg⁰ oxidation by oxygen species (lattice oxygen, perpendicularly adsorbed O2 and dissociative adsorbed O2) on the LaMnO₃(010) surface. The results indicate that Hg⁰, Hg0 and O2 can all be chemisorbed on the LaMnO₃(010) surface, with O2 capable of dissociating on the lattice. Despite variations in oxygen species, Hg⁰ oxidation proceeds via a consistent three-step mechanism: Hg⁰ → Hg (ads) → HgO (ads) → HgO. Among the species, perpendicularly adsorbed O2 is the most active oxygen for Hg⁰ oxidation, featuring the lowest rate-limiting energy barrier (1.354 eV), thus representing the most favourable pathway. This study elucidates the adsorption and oxidation mechanisms of Hg⁰ on the LaMnO₃(010) surface, offering microscopic insights into its catalytic role in mercury removal. These findings would provide a theoretical foundation for developing efficient and low-emission Hg⁰ control strategies.
| Type: | Article |
|---|---|
| Title: | Mechanistic study of Hg⁰ oxidation over LaMnO₃ oxygen carrier during chemical looping combustion |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.cej.2025.166154 |
| Publisher version: | https://doi.org/10.1016/j.cej.2025.166154 |
| Language: | English |
| Additional information: | © The Author(s), 2025. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/4.0/ |
| Keywords: | Mercury oxidation, LaMnO₃, Density functional theory, Chemical looping combustion, Reaction mechanisms |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10211875 |
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