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Copyright of Journal of Zhejiang University: Science A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To understand the absorption mechanism of nitrogen dioxide into a sodium sulfide solution, a stirred tank reactor with a plane gas-liquid interface was used to measure the chemical absorption rate of diluted nitrogen dioxide into sodium sulfide solution. The absorption rates under various experimental conditions were measured and the effects of experimental conditions on nitrogen dioxide absorption rate were discussed. The results show that, in the range of this study, nitrogen dioxide absorption rate increases with increasing sodium sulfide concentration, nitrogen dioxide inlet concentration, and flue gas flow rate, but decreases with increasing reaction temperature and oxygen content in flue gas. [ABSTRACT FROM AUTHOR]

Abstract: A combination of theoretical and experimental methods, including DFT calculation, BET, Raman spectroscopy, NH3-TPD, H2-TPR and XPS, has been used to elucidate the mechanism of lead deactivating effect on the V2O5 based SCR catalyst. The theoretical calculations have shown that the doping of lead atom will cause the great change of the surface electronic property. Each lead atom will influence two active sites, resulting in the decrease of the acid formability and reducibility of the catalyst surface. The NH3-TPD and H2-TPR experiments have shown the decrease of acid site amount and reducibility, which is in accordance with the calculation result. The BET result has also shown the physical influence caused by the doping of lead compound. The NO conversion experiment has confirmed the deactivation effect of lead on the V2O5 based catalyst. [Copyright &y& Elsevier]

Abstract: DFT calculations were carried out to study the behavior of NO2 in the selective catalytic reduction of nitric oxides with ammonia on the surface of the V2O5 catalyst. The results showed that NO2 could readily reoxidize V4+–OH through two reaction routes: (1) NO2 directly reoxidizing V4+–OH to V5+ NO2 reacting with H2O or NH3 to produce HNO3, which subsequently reoxidizes V4+–OH to V5+ te-determining step of route 1 is the desorption of cis-HNO2 from the reoxidized V5+ endothermic by 9.91kcal/mol. Route 2 possesses an energy barrier of 7.44kcal/mol, less than route 1. This energetic comparison shows that route 2 is the predominant reaction mechanism at low temperature. Reactions of the by-product, HNO2, were also investigated. The results showed that both cis-HNO2 (route 1) and trans-HNO2 (route 2) can either react with NH3, producing H2O and N2, or react with themselves, producing H2O, NO and NO2. A systemic description of the behavior for NO2 in “fast” SCR on V2O5 surface, including the reaction routes and energy profiles, has been proposed in our work. [Copyright &y& Elsevier]