Mechanism of Heterogeneous Mercury Oxidation by HBr over V2O5/TiO2 Catalyst
| العنوان: | Mechanism of Heterogeneous Mercury Oxidation by HBr over V2O5/TiO2 Catalyst |
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| المؤلفون: | Jing Liu, Zhen Zhang, Sen Miao, Zhen Wang, Bingkai Zhang, Yingju Yang |
| المصدر: | Environmental Science & Technology. 50:5398-5404 |
| بيانات النشر: | American Chemical Society (ACS), 2016. |
| سنة النشر: | 2016 |
| مصطلحات موضوعية: | Reaction mechanism, Chemistry, Selective catalytic reduction, Mercury, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Photochemistry, 01 natural sciences, Catalysis, Transition state, Dissociation (chemistry), 0104 chemical sciences, Coal, Adsorption, Physisorption, Catalytic oxidation, Environmental Chemistry, 0210 nano-technology, Oxidation-Reduction, Power Plants |
| الوصف: | Catalytic oxidation of elemental mercury (Hg(0)) through a selective catalytic reduction (SCR) system is a promising method to reduce mercury emissions from coal-burning power plants. The density functional theory (DFT) and periodic slab models were used to study the reaction mechanism of Hg(0) oxidation by HBr on V2O5/TiO2 SCR catalyst surface. The interaction mechanisms of Hg(0), HBr, HgBr, and HgBr2 on V2O5/TiO2(001) were investigated. The oxidation reaction energy profiles and the corresponding geometries of the intermediates, final states, and transition states were researched. The results indicate that Hg(0) and HgBr2 are weakly adsorbed on the oxygen sites of the V2O5/TiO2(001) surface with physisorption. HgBr is chemically adsorbed on the surface. HBr is dissociatively adsorbed on the surface with an energy barrier of 85.59 kJ/mol. The reaction of Hg(0) oxidation by HBr follows the Eley-Rideal mechanism: Hg(0) interacts with a surface Br from HBr dissociation to form HgBr, and surface HgBr further interacts with HBr to form HgBr2, last HgBr2 desorbs from the surface. Comparing the energy pathway of Hg(0) oxidation over V2O5/TiO2(001) surface by HBr to that of HCl, it is found that the dissociation energy barrier of HBr is lower than that of HCl, the formation and desorption energy barriers of HgBr2 are also lower than that of HgCl2, which explains why HBr is much more effective than HCl in promoting Hg(0) oxidation. |
| تدمد: | 1520-5851 0013-936X |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::85cac5e30b49b2b3920a7ba1a609083fTest https://doi.org/10.1021/acs.est.6b00549Test |
| رقم الانضمام: | edsair.doi.dedup.....85cac5e30b49b2b3920a7ba1a609083f |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15205851 0013936X |
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