School of Electric Power, South China University of Technology, No. 381, Wushan Road, Tianhe District, Guangzhou, 510640, China.
Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization, Guangzhou, 510640, China.
Environ Sci Pollut Res Int. 2022 Nov;29(54):81571-81582. doi: 10.1007/s11356-022-21244-4. Epub 2022 Jun 23.
Nitrogen oxides (NO) and volatile organic compounds (VOCs) are generated during the coal-fired power plant's combustion. They can be simultaneously removed in SCR (selective catalytic reduction) region. Herein, the performance of V-W/Ti and Fe-V-W/Ti synthesized by wet impregnation in removing NO and VOCs was evaluated. XPS (X-ray photoelectron spectroscopy) result indicated that a redox cycle of Fe + V ⇌ Fe + V could form electron vacancy through electron transfer. Besides, the mechanisms of NH-SCR and VOCs catalytic oxidation were explored with in situ DRIFTS experience and DFT calculation. On Fe-V-W/Ti, in situ DRIFTS study found more absorption sites of NH, and different intermediates during simultaneously removal process. DFT calculation demonstrated that absorption energy of O was decreased and O = O bond was lengthened with Fe doped. Both V-W/Ti and Fe-V-W/Ti followed the L-H mechanism and shared a common NH-SCR pathway: [Formula: see text]. However, the bidentate nitrate and monodentate nitrate were also revealed on Fe-V-W/Ti, which combined with NH and decomposed into N and HO, or NO and HO, respectively. The detected NH species combined with NO on the Fe-V-W/Ti, following the E-R mechanism. As for VOCs, the intermediates of benzene and toluene were revealed by in situ DRIFTS study, and detailed Mars-van Krevelen mechanism was discovered.
氮氧化物（NO）和挥发性有机化合物（VOCs）是在燃煤电厂燃烧过程中产生的。它们可以在 SCR（选择性催化还原）区域中同时去除。在此，通过湿浸渍合成的 V-W/Ti 和 Fe-V-W/Ti 去除 NO 和 VOCs 的性能进行了评价。XPS（X 射线光电子能谱）结果表明，Fe + V ⇌ Fe + V 的氧化还原循环可以通过电子转移形成电子空位。此外，通过原位 DRIFTS 经验和 DFT 计算探索了 NH-SCR 和 VOCs 催化氧化的机制。在 Fe-V-W/Ti 上，原位 DRIFTS 研究发现了更多的 NH 吸收位点和同时去除过程中的不同中间体。DFT 计算表明，掺杂 Fe 后，O 的吸附能降低，O = O 键变长。V-W/Ti 和 Fe-V-W/Ti 都遵循 L-H 机制，具有共同的 NH-SCR 途径：[Formula: see text]。然而，在 Fe-V-W/Ti 上也发现了双齿硝酸盐和单齿硝酸盐，它们与 NH 结合并分别分解为 N 和 HO 或 NO 和 HO。检测到的 NH 物种与 Fe-V-W/Ti 上的 NO 结合，遵循 E-R 机制。对于 VOCs，原位 DRIFTS 研究揭示了苯和甲苯的中间体，并发现了详细的 Mars-van Krevelen 机制。
