Mn/Zr改性稀土尾矿催化剂NH<sub>3</sub>-SCR脱硝机理分析

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摘要采用溶胶凝胶法制备了Mn、Mn/Zr负载稀土尾矿的NH₃-SCR催化剂，通过催化剂活性评价系统，结合H₂-TPR、NH₃-TPD、XRD和DRIFT研究了催化剂脱硝过程和反应机理.结果表明：Mn、Mn/Zr改性稀土尾矿催化剂的脱硝活性显著增强，在200℃时6% Mn1% Zr/稀土尾矿催化剂脱硝活性可达96%.改性后催化剂表面氧空位、B酸性位点及吸附物种数量明显增加，催化剂还原峰面积增大，其氧化还原性能的提升是活性提高的主要原因.催化剂B酸位NH₄⁺与气态NO₂的反应遵循E-R机理，NH₄⁺与单齿、双齿硝酸盐物种的反应遵循L-H机理.

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	焦坤灵
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	武文斐

关键词 ：稀土尾矿, Mn、Zr改性, 催化剂, NH₃-SCR, 脱硝机理

Abstract：Mn and Mn/Zr modified rare earth tailings-based NH₃-SCR catalysts were prepared using the sol-gel method. The catalysts were characterized using a catalyst activity evaluation system, along with H₂-TPR, NH₃-TPD, XRD, and DRIFT techniques, to investigate the denitration process and reaction mechanism. The results showed that the denitration activity of the Mn and Mn/Zr modified rare earth tailings catalysts was significantly enhanced, with a denitration activity of 96% achieved at 200℃ for the 6%Mn1%Zr/rare earth tailings catalyst. The modified catalysts exhibited increased oxygen vacancies and acidic sites on the surface, as well as a higher adsorption capacity. The increase in reducible surface area of the catalysts contributed to the improvement of their redox performances. The reaction between NH₄⁺ and gaseous NO₂ on the acidic sites of the catalysts followed the E-R mechanism, while the reactions between NH₄⁺ and monodentate and bidentate nitrate species followed the L-H mechanism.

Key words： rare earth tailings Mn、Zr modified catalysts NH₃-SCR denitration mechanism

收稿日期: 2023-03-13

PACS:

X511

基金资助:内蒙古自治区自然科学基金重大项目（2019ZD13）；内蒙古自治区高校基本科研项目（2022098）

通讯作者: 武文斐,教授,wwf@imust.edu.cn E-mail: wwf@imust.edu.cn

作者简介: 焦坤灵(1984-),男,内蒙古赤峰人,副教授,博士,主要从事燃煤烟气污染控制和稀土尾矿脱硝催化剂研究.发表论文10余篇.jiaokunling@imust.cn.

引用本文:

焦坤灵, 焦晓云, 刘佳杰, 李娜, 侯丽敏, 武文斐. Mn/Zr改性稀土尾矿催化剂NH₃-SCR脱硝机理分析[J]. 中国环境科学, 2023, 43(11): 5655-5662. JIAO Kun-ling, JIAO Xiao-yun, LIU Jia-jie, LI Na, HOU Li-min, WU Wen-fei. A Study of Mn/Zr modification for NH₃-SCR denitration mechanism of rare earth tailings. CHINA ENVIRONMENTAL SCIENCECE, 2023, 43(11): 5655-5662.

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http://www.zghjkx.com.cn/CN/ 或 http://www.zghjkx.com.cn/CN/Y2023/V43/I11/5655

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