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【目的】燃煤电厂排放的NOx会对环境造成严重危害。因此，严格控制烟气中NOx的排放有利于降低燃煤电厂对大气环境的污染，从而提升空气环境质量。目前，氨选择性催化还原法(ammonia-selective catalytic reduction,NH_3-SCR)是应用最为广泛的实现烟气脱硝的方法，该技术的核心是高效催化剂的设计。为提升MnOx催化剂的脱硝效率，需要首先研究沉淀剂用量对其活性的影响。【方法】本研究采用共沉淀法制备了不同沉淀剂用量的MnOx催化剂。并通过一系列表征测试手段，对不同沉淀剂用量的催化剂进行对比分析，探究沉淀剂用量对催化剂活性的影响机理。【结果】研究表明，以0.1 mol氨水为沉淀剂制备的0.1AH-MnOx催化剂表现出最优的催化活性，在200～300℃范围内，NO转化率可达95%以上。沉淀剂用量过多加剧了催化剂的团聚现象，导致催化剂颗粒状结构增大，使得催化剂的比表面积、平均孔径和孔容减小。另外，随着沉淀剂用量的增加，催化剂的表面酸性也随之减小。这与催化剂的比表面积减小有关，而催化剂的比表面积减小导致催化剂表面的活性位点减少，不利于NH3的吸附和活化，最终导致催化剂的反应活性下降。0.1AH-MnOx催化剂的脱硝性能略优于0.2AH-MnOx催化剂。但由于0.1AH-MnOx催化剂沉淀剂用量较少，使得催化剂产量较低，导致生产成本增加。并且0.2AH-MnOx与0.1AH-MnOx催化剂的形貌结构、比表面积和表面酸性差异最小，同时0.2AH-MnOx催化剂具有较高产量。【结论】因此，通过沉淀法制备催化剂，不仅要优化沉淀剂的种类，还要注重从沉淀剂用量和成本等方面进行综合考虑，以达到最优效果。
Abstract：[Objective] The NOx emissions from solid fuel combustion in coal-fired power plants can cause serious harm to the environment. Therefore, strict control of NO emissions in flue gas is beneficial for reducing the pollution of coalfired power plants to the atmospheric environment, thereby improving air quality. At present, Ammonia Selective Catalytic Reduction(NH_3-SCR) is the most widely used method for achieving flue gas denitrification, and the core of this technology is the design of efficient catalysts. In order to improve the denitrification efficiency of MnOx catalyst, it is necessary to study the effect of precipitant dosage on its activity. [Methods] In this study, MnOx catalysts with different amounts of precipitants were prepared using co precipitation method. And through a series of characterization testing methods, a comparative analysis was conducted on catalysts with different amounts of precipitants to explore the mechanism of the influence of precipitant dosage on catalyst activity.[Results] The results showed that the 0.1 AH-MnOx catalyst prepared with 0.1 mol ammonia water as the precipitant exhibited the best catalytic activity, with a NO conversion rate of over 95% in the range of 200-300 ℃. Through characterization results such as scanning electron microscopy and N2 adsorption desorption testing, it was found that excessive use of precipitant exacerbated the agglomeration phenomenon of the catalyst, promoted the increase of the catalyst particle structure, and reduced the specific surface area, average pore size, and pore volume of the catalyst. In addition, NH_3-TPD test results showed that as the amount of precipitant increased, the surface acidity of the catalyst also decreased. This is related to the decrease in the specific surface area of the catalyst, which leads to a reduction in the active sites on the catalyst surface, which is not conducive to the adsorption and activation of NH3, ultimately resulting in a decrease in the reaction activity of the catalyst. The denitrification performance of 0.1 AH MnOx catalyst is slightly better than that of 0.2 AH MnOx catalyst. However, due to the low amount of precipitant used in the 0.1 AH-MnOx catalyst, the catalyst yield is low, resulting in increased production costs. And the morphology, specific surface area, and surface acidity differences between 0.2 AHMnOx and 0.1 AH-MnOx catalysts are minimal, while the 0.2 AH-MnOx catalyst has a higher yield.[Conclusion] Therefore, when preparing catalysts by precipitation method, it is not only necessary to optimize the type of precipitant, but also to pay attention to comprehensive considerations from the aspects of precipitant dosage and cost, in order to achieve the optimal effect.
[1]苏新.烟气脱硫脱硝技术的现状与发展探讨[J].皮革制作与环保科技, 2022, 3(3):161-162+165.SU XIN. Discussion on the current status and development of flue gas desulfurization and denitrification technology[J]. Leather production and environmental protection technology, 2022, 3(3):161-162+165.
[2]中华人民共和国国家统计局.中国统计年鉴[M].北京:中国统计出版社, 2023.National bureau of statistics of the people's republic of China.China statistical yearbook[M]. Beijing:China statistical publishing house, 2023.
[3]梁宇宁,黄纪荣,李国峰,等,燃煤电厂SCR烟气脱硝效率影响因素研究[J].化学工程师, 2024, 38(2):38-41.LIANG Yuning, HUANG Jirong, LI Guofeng, et al. Study on the influencing factors of SCR flue gas denitrification efficiency in coal-fired power plants[J]. Chemical Engineer, 2024, 38(2):38-41.
[4]李国峰,仲超,郭凯凌,等,可再生SCR催化剂在烟气脱硝优化改造中的应用[J].能源化工, 2023, 44(6):68-72.LI Guofeng, ZHONG Chao, GUO Kailing, et al. Application of Renewable SCR catalysts in optimization and transformation of flue gas denitrification[J]. Energy and Chemical Engineering, 2023,44(6):68-72.
[5]黄裕章,超低排放背景下的大气治理技术与施工建议[J].山西化工, 2021, 41(5):252-254+260.HUANG Yuzhang, Atmospheric control technology and construction suggestions under the background of ultra low emissions[J]. Shanxi Chemical Industry, 2021, 41(5):252-254+260.
[6]LI Shuhao, WANG Feng, Ng Derrick, et al., A facile MnSO4surface coated NiMnFeOx catalyst with enhanced SO2 resistance for SCR reaction:A dual-protection mechanism[J]. Applied Catalysis B:Environmental, 2024, 342:123441.
[7]ZHANG Jiadong, MA Zengyi, CAO Ang, et al. Research progress of Mn-based low-temperature SCR denitrification catalysts[J]. RSC advances, 2024, 14:32583-32601.
[8]YE Lyumeng, LU Peng, CHEN Xiongbo, et al. The deactivation mechanism of toluene on MnOx-CeO2 SCR catalyst[J]. Applied Catalysis B:Environmental, 2020, 277:119257.
[9]YE Bora, KIM JINWOO, LEE Myeungjin, et al. Mn-Ce oxide nanoparticles supported on nitrogen-doped reduced graphene oxide as low-temperature catalysts for selective catalytic reduction of nitrogen oxides[J]. Microporous and Mesoporous Materials, 2021,310:110588.
[10]YOON Wongeun, KIM Youngmin, KIM Geojong, et al. Boosting low temperature De-NOx performance and SO2 resistance over Cedoped two dimensional Mn-Cr layered double oxide catalyst[J].Chemical Engineering Journal, 2022, 434:134676.
[11]LI Shuhao, WANG Feng, XIE Zongli, et al. A novel core-shell structured Fe@CeO2-ZIF-8 catalyst for the reduction of NO by CO[J]. Journal of Catalysis, 2023, 421:240-251.
[12]XIE Shaohua, TAN Wei, LI Yuejin, et al. Copper single atomtriggered niobia-ceria catalyst for efficient low-temperature reduction of nitrogen oxides[J]. ACS Catalysis, 2022, 12:2441-2453.
[13]ZHANG Huirong, LI Yuhang, NIU Jian, et al. Enhanced metalsupport interaction through activated carbon structure optimization:new insights into enhanced NH3-SCR performance of Fe-Mn/AC catalysts[J]. Journal of Environmental Chemical Engineering, 2025:116820.
[14]毛湘雲,顾玉顺,伍豪,等, SCR脱硝控制技术在燃煤锅炉中的应用研究[J].当代化工, 2023, 52(10):2305-2308+2316.MAO Xiangyun, GU Yushun, WU Hao, et al. Application research of SCR denitrification control technology in coal fired boilers[J]. Contemporary Chemical Industry, 2023, 52(10):2305-2308+2316.
[15]GUO Kai, JI Jiawei, SONG Wang, et al. Conquering ammonium bisulfate poison over low-temperature NH3-SCR catalysts:A critical review[J]. Applied Catalysis B:Environmental, 2021, 297:120388.
[16]YAN Tao, LIU Qi, WANG Shihao, et al. Promoter rather than inhibitor:phosphorus incorporation accelerates the activity of V2O5-WO3/TiO2 catalyst for selective catalytic reduction of NOx by NH3[J]. ACS Catalysis, 2020, 10:2747-2753.
[17]ZHANG Yanbing, WANG Xie, LIANG Banglei, et al. An investigation on reaction principles of Mn-Fe-CeOx catalyst system:Guide the synthesis of low-temperature NH3-SCR catalytic filter[J]. Environmental Technology&Innovation, 2025,37:103926.
[18]WU Hangmi, DAI Xiaoyu, TENG Wenxin, et al. Unveiling the Enhancement Mechanism of NH3-SCR Performance in Mnmodified α-Fe2O3 on Fe2O3-TiO2 Catalysts with Varied Crystal Facets[J]. Journal of Alloys and Compounds, 2025:181351.
[19]ZHU Wenjuan, TANG Xiaolong, GAO Fengyu, et al., The effect of non-selective oxidation on the Mn2Co1Ox catalysts for NH3-SCR:Positive and non-positive[J]. Chemical Engineering Journal,2020, 385:123797.
[20]WANG Xiaoying, LIU Fei, XU ZhaoYang, et al. Mn modified Cu-SSZ-13 catalysts with excellent NH3-SCR activity and hydrothermal stability[J]. Journal of Environmental Chemical Engineering, 2025:117421.
[21]HOU Limin, LI Jiaming, LI Haobo, et al., Iron-containing tailings catalyst modified by Mn for SCR of NO with NH3 at low temperature:Study of carrier treatment and calcination temperature[J]. Fuel, 2025, 382:133731.
[22]PAN Hua, CHEN Zhenghui, MA Mudi, et al. Mutual inhibition mechanism of simultaneous catalytic removal of NOx and toluene on Mn-based catalysts[J]. Journal of Colloid and Interface Science, 2022, 607:1189-1200.
[23]WEI Fangjia, LIU Lifei, WANG Chen, et al. Cu(Mn)MgAl mixed oxides with enhanced performance for simultaneous removal of NOx and toluene:Insight into the better collaboration of CuO and MnOx via layered double hydroxides(LDHs)precursor template[J]. Chemical Engineering Journal, 2023, 462:142150.
[24]SHAO Jiaming, WANG Zhihua, LIU Peixi, et al. Interplay effect on simultaneous catalytic oxidation of NOx and toluene over different crystal types of MnO2 catalysts[J]. Proceedings of the Combustion Institute, 2021, 38:5433-5441.
[25]YAO Guihuan, WEI Yuliang, GUI Keting, et al. Catalytic performance and reaction mechanisms of NO removal with NH3 at low and medium temperatures on Mn-W-Sb modified siderite catalysts[J]. Journal of environmental sciences, 2022, 115:126-139.
[26]ZHOU Xing, WANG Penglu, SHEN Zhi, et al. Low-temperature NOx reduction over hydrothermally stable SCR catalysts by engineering low-coordinated Mn active sites[J]. Chemical Engineering Journal, 2022, 442:136182.
[27]WEI Lingang, GUO Ruitang, ZHOU Jue, et al. Chemical deactivation and resistance of Mn-based SCR catalysts for NOx removal from stationary sources[J]. Fuel, 2022, 316:123438.
[28]王献忠,吴彦霞,赵春林,等,共沉淀法制备的Mn-Ce/TiO2催化剂低温脱硝性能研究[J].人工晶体学报, 2017, 46(11):2271-2276.WANG Xianzhong, WU Yanxia, ZHAO Chunlin, et al. Low temperature denitrification performance of Mn Ce/TiO2 catalyst prepared by co precipitation method[J]. Journal of Artificial Crystals, 2017, 46(11):2271-2276.
[29]SHAN Wenpo, LIU Fudong, HE Hong, et al., A superior Ce-W-Ti mixed oxide catalyst for the selective catalytic reduction of NOx with NH3[J]. Applied Catalysis B:Environmental, 2012, 115:100-106.
[30]刘育松,高凤雨,唐晓龙,等,制备条件对锰氧化物SCR脱硝性能的影响[J].环境工程学报, 2016, 10(01):295-300.LIU Yusong, GAO Fengyu, TANG Xiaolong, et al. Effects of preparation conditions on the denitrification performance of manganese oxide SCR[J]. Journal of Environmental Engineering,2016, 10(01):295-300.
[31]LIU Lijun, SHEN Boxiong, LU Fengju, et al. Highly efficient Mn-Fe bimetallic oxides for simultaneous oxidation of NO and toluene:Performance and mechanism[J]. Fuel, 2023, 332:126143.
[32]DAI Weili, ZOU Moliang, ZHAO Chuang, et al., Monoatomic oxygen fueled by oxygen vacancies governs the photothermocatalytic deep oxidation of toluene on Na-doped Co3O4[J]. Applied Catalysis B:Environmental, 2022, 317:121769.
[33]张磊,雷俊腾,田园,等,前驱体和沉淀剂浓度对CuO/ZnO/CeO2-ZrO2甲醇水蒸气重整制氢催化剂性能的影响[J].燃料化学学报, 2015, 43(11):1366-1374.ZHANG Lei, LEI Junteng, Tianyuan, et al. Effects of precursor and precipitant concentrations on the performance of CuO/ZnO/CeO2-ZrO2 methanol steam reforming hydrogen production catalyst[J]. Journal of Fuel Chemistry, 2015, 43(11):1366-1374.
[34]张倩,于楠,孙运林,等,四氯乙烷催化脱氢生产四氯乙烯催化剂研究——沉淀剂浓度对催化剂性能的影响[J].工业催化,2015, 23(9):724-728.ZHANG Qian, YU Nan, SUN Yunlin, et al. Study on catalysts for catalytic dehydrogenation of tetrachloroethane to produce tetrachloroethylene:The effect of precipitation agent concentration on catalyst performance[J]. Industrial Catalysis, 2015, 23(9):724-728.
[35]KHAN AIMAL, WANG Huabin, LIU Yong, et al. Highly efficientα-Mn2O3@α-MnO2-500 nanocomposite for peroxymonosulfate activation:comprehensive investigation of manganese oxides[J].Journal of Materials Chemistry A, 2018, 6:1590-1600.
[36]KANG Keke, YAO Xiaojiang, HUANG Yike, et al. Insights into the co-doping effect of Fe3+and Zr4+on the anti-K performance of CeTiOx catalyst for NH3-SCR reaction[J]. Journal of Hazardous Materials, 2021, 416:125821.
[37]杜振,朱文韬,张杨,等, SCR脱硝催化剂全寿命周期性能变化规律研究[J].中国电机工程学报, 2022, 42(16):5996-6004+6174.DU Zhen, ZHU Wentao, ZHANG Yang, et al. Study on the Performance Changes of SCR Denitrification Catalysts throughout their Life Cycle[J]. Chinese Journal of Electrical Engineering,2022, 42(16):5996-6004+6174.
[38]张志中,孙强,姜肇中,等,基于性能检测的SCR脱硝催化剂寿命管理分析[J].电力科技与环保, 2023, 39(1):59-70.ZHANG Zhizhong, SUN Qiang, JIANG Zhaozhong, et al. Life Management Analysis of SCR Denitrification Catalysts Based on Performance Testing[J]. Electric Power Technology and Environmental Protection, 2023, 39(1):59-70.
[39]姜树栋,利用臭氧及活性分子协同脱除多种污染物的实验及机理研究,[D]. 2010.JIANG Shudong, Experimental and mechanistic study on the synergistic removal of various pollutants using ozone and active molecules[D]. 2010.
[40]Liotta Leonarda Francescal, Catalytic oxidation of volatile organic compounds on supported noble metals[J]. Applied Catalysis B:Environmental, 2010, 100:403-412.
[41]张超, Pt基纳米催化剂的结构调控及其性能研究,[D]. 2018.ZHANG Chao, Structural Control and Performance Study of Pt based Nanocatalysts[D]. 2018.
[42]ZENG Yiqing, SONG Wang, WANG Yanan, et al. Novel Fedoped CePO4 catalyst for selective catalytic reduction of NO with NH3:The role of Fe3+ions[J]. Journal of Hazardous Materials,2020, 383:121212.
[43]GAO Jian, DAI Xinrui, GU Zhenhua, et al., Insight into M(M=Mn, Co, Ce)loaded cold-rolling sludge catalysts for NOx removal with NH3-SCR at low-temperature[J]. Inorganic Chemistry Communications, 2025:113984.
[44]LIU Lu, WANG Bangda, YAO Xiaojiang, et al., Highly efficient MnOx/biochar catalysts obtained by air oxidation for lowtemperature NH3-SCR of NO[J]. Fuel, 2021, 283:119336.
[45]LIU Tao, SU Sheng, LIU Lijun, et al., Mechanistic investigation of the suppressed N2O formation during the low-temperature NH3-SCR over the Sb-modified Mn/Ti catalyst[J]. Chemical Engineering Journal, 2024, 499:156301.
[46]CHEN Yin, LIAO Yanfen, CHEN Lin, et al., Performance of transition metal(Cu, Fe and Co)modified SCR catalysts for simultaneous removal of NO and volatile organic compounds(VOCs)from coalfired power plant flue gas[J]. Fuel, 2021, 289:119849.
[47]KANG Dongrui, SHI Qiqi, ZHANG Chenguang, et al., Synergistic removal of NOx and CB by Co-MnOx catalysts in a low-temperature window[J]. Chemical Engineering Journal, 2023, 476:146369.
[48]LIN Fawei, WANG Zhihua, ZHANG Zhiman, et al., Flue gas treatment with ozone oxidation:An overview on NOx, organic pollutants, and mercury[J]. Chemical Engineering Journal, 2020, 382:123030.
基本信息:
DOI：10.19944/j.eptep.1674-8069.2025.05.012
中图分类号:X773
引用信息:
[1]封硕,刘欢欢,吕轩,等.沉淀剂用量对MnO_x催化剂脱硝性能的影响机理研究[J].电力科技与环保,2025,41(05):811-821.DOI:10.19944/j.eptep.1674-8069.2025.05.012.
基金信息:
河北省高等学校科学研究项目（ZC2025090）