School of Ecology and Environment, Zhengzhou University, Zhengzhou 450001, PR China; College of Environmental Science and Engineering, Nankai University, Tianjin 300350, PR China.
College of Environmental Science and Engineering, Nankai University, Tianjin 300350, PR China; Lund University, Lund 22100, Sweden.
J Hazard Mater. 2021 Oct 15;420:126640. doi: 10.1016/j.jhazmat.2021.126640. Epub 2021 Jul 14.
Electrochemical removal of nitrogen oxides (NO) by solid electrolyte cells (SECs) is a promising technology due to no required reductant. Herein, a series of LaSrMnNiO (0 ≤ x ≤ 0.5) perovskites were first synthesized and utilized as the electrode materials of SECs. The role of Ni substitution in electrode performance and NO reduction mechanism were revealed by various experimental characterization and first-principle calculations. The results indicate that the moderate Ni substitution (x ≤ 0.3) increased the NO conversion of electrodes while reduced the polarization resistance. The further investigation shows that this improvement was attributed to the more surface oxygen vacancies, better reducibility and higher Mn proportion of the Ni-substituted perovskites. The electrochemical impedance spectroscopy (EIS) shows that these changes facilitated the NO adsorption and dissociation processes on the electrode. According to first-principle calculations, the Ni-substituted perovskite had a lower formation energy of surface oxygen vacancy, while the NO molecule adsorbed on defect surface gained more electrons thus was easier to be reduced and dissociated. Finally, the electrode performance at different operating temperatures and the operational stability were verified.
通过固体电解质电池 (SECs) 电化学去除氮氧化物 (NO) 是一种很有前途的技术，因为它不需要还原剂。本文首次合成了一系列 LaSrMnNiO（0≤x≤0.5）钙钛矿，并将其用作 SECs 的电极材料。通过各种实验表征和第一性原理计算揭示了 Ni 取代在电极性能和 NO 还原机制中的作用。结果表明，适度的 Ni 取代（x≤0.3）提高了电极的 NO 转化率，同时降低了极化电阻。进一步的研究表明，这种改善归因于 Ni 取代钙钛矿具有更多的表面氧空位、更好的还原性和更高的 Mn 比例。电化学阻抗谱 (EIS) 表明这些变化促进了电极上的 NO 吸附和解离过程。根据第一性原理计算，Ni 取代的钙钛矿具有更低的表面氧空位形成能，而吸附在缺陷表面上的 NO 分子获得了更多的电子，因此更容易被还原和解离。最后，验证了不同操作温度下的电极性能和操作稳定性。
