生物质活性炭负载零价铁纳米晶簇直接催化还原NO

doi:10.11949/j.issn.0438-1157.20180947

摘要/Abstract

摘要：

采用等体积浸渍法制备以生物质活性炭为载体的纳米铁基催化剂，利用TG、SEM、XPS、Raman等分析仪器对催化剂进行表征，探讨了活性炭负载零价铁和铁氧化物在无氧条件下脱硝的机理。结果表明：在750℃热还原条件下制得的铁基催化剂具备较高的活性，其活性中心是分散均匀的零价铁纳米晶簇。在280℃无氧条件下对NO的脱除效率达100%，且避免了活性炭载体的损耗。研究发现，催化剂快速失活是由于零价Fe被氧化为Fe₃O₄，因而降低了脱硝剂的活性。直接对失活催化剂进行热还原可以完全恢复活性，但这种方法会消耗炭载体；利用CO作为还原剂进行制备与再生，可以有效提高纳米晶簇的分散性，延长脱硝寿命并减少炭载体的损失，为零价Fe催化剂在实际应用中提供了可能性。

关键词: 催化剂, 再生, 活性炭, 低温脱硝, 零价铁

Abstract:

The nano-iron-based catalysts with biomass activated carbon as carrier were prepared by equal volume impregnation method. The catalysts were characterized by TG, SEM, XPS, Raman and other analytical instruments. The activated carbon was loaded with zero-valent iron and iron oxide under anaerobic conditions. Actively developing a cheap catalyst suitable for coke oven flue gas denitrification at low temperature and no oxygen so that its flue gas emissions meet the national environmental protection standards is one of the research hotspots at the present stage. The mechanism of denitrification of zero-valent iron and iron oxides supported on activated carbon under anaerobic conditions is discussed. The results prove that the Fe-based catalyst prepared by thermal reduction at 750℃ has high activity, and its active center is the homogeneously dispersed zero-valent iron nanocrystalline cluster. The removal efficiency of NO at 280℃ is 100% and the loss of activated carbon carrier was avoided. The fast deactivation of the catalyst is due to the oxidation of zero-valent iron to Fe₃O₄, thus reducing the activity of the denitrifying agent. The catalyst activity can be completely restored by heat treatment at 750℃ nitrogen atmosphere, but the carbon carrier will be consumed by regeneration method without adding reducing gas. The preparation and regeneration of CO as reducing agent can effectively improve the dispersion of nanocrystalline clusters, prolong the denitrification life and reduce the loss of carbon support, which provides the possibility for the application of zero valent Fe catalyst in practical application.

Key words: catalyst, regeneration, activated carbon, low temperature denitrification, zero-valent iron

中图分类号:

TK 6

李艳鹰, 李先春. 生物质活性炭负载零价铁纳米晶簇直接催化还原NO[J]. 化工学报, 2019, 70(3): 1111-1119.

Yanying LI, Xianchun LI. Biomass activated carbon loaded with zero-valent iron nanocrystal clusters for direct catalytic reduction of NO[J]. CIESC Journal, 2019, 70(3): 1111-1119.

图/表 14

图1 脱硝实验装置

Fig.1 Experimental rigs of denitrification

表1 脱硝反应实验条件

Table 1 Parameters of experimental conditions for denitrification

温度	空速	NO浓度
280℃	6000 h^-1	300×10^-6

图2 活性炭浸渍硝酸铁的热重分析

Fig.2 Thermogravimetric analysis of iron nitrate impregnated with activated carbon

图3 催化剂的XRD谱图

Fig.3 XRD patterns of catalysts

图4 活性炭负载零价铁无氧脱硝

Fig.4 Oxygen-free denitrification of zero-valent iron supported on activated carbon

图5 催化剂的表面形貌

Fig.5 Surface morphology of catalyst

图6 活性炭负载Fe2O3脱硝前后的XRD谱图

Fig.6 XRD patterns of activated carbon loaded Fe2O3 before and after denitrification

图7 催化剂的Raman谱图

Fig.7 Raman spectra of catalysts

图8 活性炭负载Fe2O3无氧脱硝

Fig.8 Oxygen-free denitrification of Fe2O3 supported on activated carbon

图9 生物质活性炭负载零价铁无氧脱硝

Fig.9 Oxygen-free denitrification of zero-valent iron supported on biomass activated carbon

图10 催化剂表面形貌

Fig.10 Surface morphology of catalysts

图11 Fe2p XPS能谱分析

Fig.11 Fe2p XPS spectra analysis

图12 脱硝实验中增加CO时的脱硝效率

Fig.12 Denitrification efficiency when CO is added in denitrification experiment(Fe=5%(mass)，S=6000 h-1，cNO=300×10-6)a—T=280℃，cCO=0； b—T=280℃，cCO=100×10-6； c—T=350℃，cCO=0； d—T=350℃，cCO=100×10-6

图13 NO-TPO曲线

Fig.13 NO-TPO curve

参考文献 29

1	LiuG, GaoP X. A review of NO_x storage/reduction catalysts: mechanism, materials and degradation studies[J]. Catalysis Science & Technology, 2011, 1(4): 552-568.
2	BoningariT, PanagiotisG S. Nickel-doped Mn/TiO₂ as an efficient catalyst for the low-temperature SCR of NO with NH₃: catalytic evaluation and characterizations [J]. Journal of Catalysis, 2012, 288: 74-83.
3	ShiL N, ZhangX, ChenZ L. Removal of chromium (Ⅵ) from wastewater using bentonite-supported nanoscale zero-valent iron[J]. Water Research, 2011, 45(2): 886-892.
4	ZhangX, LinS, ChenZ, et al. Kaolinite-supported nanoscale zero-valent iron for removal of Pb²⁺ from aqueous solution: reactivity, characterization and mechanism[J]. Water Research, 2011, 45(11): 3481-3488.
5	KimS A , Kamala-KannanS , LeeK J , et al. Removal of Pb(II) from aqueous solution by a zeolite–nanoscale zero-valent iron composite[J]. Chemical Engineering Journal, 2013, 217: 54-60.
6	LingL, PanB, ZhangW X. Removal of selenium from water with nanoscale zero-valent iron: mechanisms of intraparticle reduction of Se(IV)[J]. Water Research, 2015, 71: 274-281.
7	ChenH, CaoY, WeiE, et al. Facile synthesis of graphene nano zero-valent iron composites and their efficient removal of trichloronitromethane from drinking water[J]. Chemosphere, 2016, 146: 32-39.
8	HayhurstA N, NinomiyaY. Kinetics of the conversion of NO to N₂, during the oxidation of iron particles by NO in a hot fluidised bed[J]. Chemical Engineering Science, 1998, 53(8): 1481-1489.
9	HayhurstA N, LawrenceA D. The reduction of the nitrogen oxides NO and N₂O to molecular nitrogen in the presence of iron, its oxides, and carbon monoxide in a hot fluidized bed[J]. Combustion & Flame, 1997, 110(3): 351-365.
10	GradońB, LasekJ. Investigations of the reduction of NO to N₂ by reaction with Fe[J]. Fuel, 2010, 89(11): 3505-3509.
11	苏亚欣, 苏阿龙, 成豪.金属铁直接催化还原NO的实验研究[J].煤炭学报, 2013, 38(1): 206-210.
	SuY X, SuA L, ChengH. Experimental study on direct catalytic reduction of NO by metallic iron[J].Journal of China Coal Society, 2013, 38(1): 206-210.
12	MiuraK, NakagawaH, KitauraR, et al. Low-temperature conversion of NO to N₂ by use of a novel Ni loaded porous carbon[J]. Chemical Engineering Science, 2001, 56(4): 1623-1629.
13	SunY P, LiX, CaoJ, et al. Characterization of zero-valent iron nanoparticles[J]. Adv. Colloid Interface Sci., 2006, 120(1): 47-56.
14	XiaoJ, XuQ, XuQ, et al. Direct promotion effect of Fe on no reduction by activated carbon loaded with Fe species[J]. Journal of Chemical Thermodynamics, 2016, 95: 216-230.
15	Illán-GómezM J, Linares-SolanoA, Salinas-MartinezD L C, et al. Nitrogen oxide (NO) reduction by activated carbons (1): The role of carbon porosity and surface area[J]. Energy & Fuels, 1993, 7(1): 146-154.
16	Illán-GómezM J, Linares-SolanoA, RadovicL R. NO reduction by activated carbons(5): Catalytic effect of iron[J]. Energy & Fuels, 1995, 9(3): 97-103.
17	Illán-GómezM J, Linares-SolanoA, RadovicL R, et al. NO reduction by activated carbons(3): Influence of catalyst loading on the catalytic effect of potassium[J]. Energy & Fuels, 1995, 9(1): 104-111.
18	Illán-GómezM J, Linares-SolanoA, RadovicL R, et al. NO reduction by activated carbons(4): Catalysis by calcium[J]. Energy & Fuels, 1995, 9(1): 112-118.
19	Illán-GómezM J, Linares-SolanoA, RadovicL R. NO reduction by activated carbons(2): Catalytic effect of potassium[J]. Fuel & Energy Abstracts, 1995, 36(1): 97-103.
20	Illán-GómezM J, Linares-SolanoA, LeceaS M D. NO reduction by activated carbon(6): Catalysis by transition metals[J]. Energy Fuels, 1995, 9(6): 976-983.
21	Illán-GómezM J, Linares-SolanoA, RadovicL R, et al. NO reduction by activated carbons(7): Some mechanistic aspects of uncatalyzed and catalyzed reaction[J]. Energy & Fuels, 1996, 10: 158-168.
22	TengH, SuubergE M. Chemisorption of nitric oxide on char(1): Reversible nitric oxide sorption[J]. Cheminform, 1993, 24(16): 478-483.
23	TengH, SuubergE M. Chemisorption of nitric oxide on char(2): Irreversible carbon oxide formation[J]. Industrial & Engineering Chemistry Research, 1993, 32(3): 416-423.
24	LiX, DongZ, DouJ, et al. Catalytic reduction of NO using iron oxide impregnated biomass and lignite char for flue gas treatment[J]. Fuel Processing Technology, 2016, 148: 91-98.
25	de FariaD L A, VenâncioS, de OliveiraM T. Raman microspectroscopy of some iron oxides and oxyhydroxides[J]. Journal of Raman Spectroscopy, 1997, 28(11): 873-878.
26	胡涛, 路欣, 阎研, 等. 用纯铁氧化法生长的铁氧化物样品的Raman光谱研究[J].光谱学与光谱分析, 2004, 24(9): 1072-1074.
	HuT, LuX, YanY, et al. Raman spectroscopic study on the iron oxide film prepared by iron oxidation method[J]. Spectroscopy and Spectral Analysis, 2004, 24(9): 1072-1074.
27	GrosvenorA P, KobeB A, BiesingerM C, et al. Investigation of multiplet splitting of Fe 2p XPS spectra and bonding in iron compounds[J]. Surface and Interface Analysis, 2004, 36(12): 1564-1574.
28	胡慧萍, 王梦, 丁治英, 等. FT-IR、XPS和DFT研究水杨酸钠在针铁矿或赤铁矿上的吸附机理[J].物理化学学报, 2016, 32(8): 2059-2068.
	HuH P, WangM, DingZ Y, et al. FT-IR, XPS and DFT study of the adsorption mechanism of sodium salicylate onto goethite or hematite[J]. Acta Phys.–Chim. Sin., 2016, 32(8): 2059-2068.
29	ZhangS, ZhangH, ZhangW, et al. Induced growth of Fe-N_x active sites using carbon templates[J]. Chinese Journal of Catalysis, 2018, (8): 1427-1435.

[1]	车睿敏, 郑文秋, 王小宇, 李鑫, 许凤. 基于离子液体的纤维素均相加工研究进展[J]. 化工学报, 2023, 74(9): 3615-3627.
[2]	杨学金, 杨金涛, 宁平, 王访, 宋晓双, 贾丽娟, 冯嘉予. 剧毒气体PH₃的干法净化技术研究进展[J]. 化工学报, 2023, 74(9): 3742-3755.
[3]	李艺彤, 郭航, 陈浩, 叶芳. 催化剂非均匀分布的质子交换膜燃料电池操作条件研究[J]. 化工学报, 2023, 74(9): 3831-3840.
[4]	陈杰, 林永胜, 肖恺, 杨臣, 邱挺. 胆碱基碱性离子液体催化合成仲丁醇性能研究[J]. 化工学报, 2023, 74(9): 3716-3730.
[5]	杨菲菲, 赵世熙, 周维, 倪中海. Sn掺杂的In₂O₃催化CO₂选择性加氢制甲醇[J]. 化工学报, 2023, 74(8): 3366-3374.
[6]	李凯旋, 谭伟, 张曼玉, 徐志豪, 王旭裕, 纪红兵. 富含零价钴活性位点的钴氮碳/活性炭设计及甲醛催化氧化应用研究[J]. 化工学报, 2023, 74(8): 3342-3352.
[7]	杨欣, 彭啸, 薛凯茹, 苏梦威, 吴燕. 分子印迹-TiO₂光电催化降解增溶PHE废水性能研究[J]. 化工学报, 2023, 74(8): 3564-3571.
[8]	吕龙义, 及文博, 韩沐达, 李伟光, 高文芳, 刘晓阳, 孙丽, 王鹏飞, 任芝军, 张光明. 铁基导电材料强化厌氧去除卤代有机污染物：研究进展及未来展望[J]. 化工学报, 2023, 74(8): 3193-3202.
[9]	余娅洁, 李静茹, 周树锋, 李清彪, 詹国武. 基于天然生物模板构建纳米材料及集成催化剂研究进展[J]. 化工学报, 2023, 74(7): 2735-2752.
[10]	涂玉明, 邵高燕, 陈健杰, 刘凤, 田世超, 周智勇, 任钟旗. 钙基催化剂的设计合成及应用研究进展[J]. 化工学报, 2023, 74(7): 2717-2734.
[11]	张琦钰, 高利军, 苏宇航, 马晓博, 王翊丞, 张亚婷, 胡超. 碳基催化材料在电化学还原二氧化碳中的研究进展[J]. 化工学报, 2023, 74(7): 2753-2772.
[12]	屈园浩, 邓文义, 谢晓丹, 苏亚欣. 活性炭/石墨辅助污泥电渗脱水研究[J]. 化工学报, 2023, 74(7): 3038-3050.
[13]	文兆伦, 李沛睿, 张忠林, 杜晓, 侯起旺, 刘叶刚, 郝晓刚, 官国清. 基于自热再生的隔壁塔深冷空分工艺设计及优化[J]. 化工学报, 2023, 74(7): 2988-2998.
[14]	李盼, 马俊洋, 陈志豪, 王丽, 郭耘. Ru/α-MnO₂催化剂形貌对NH₃-SCO反应性能的影响[J]. 化工学报, 2023, 74(7): 2908-2918.
[15]	张谭, 刘光, 李晋平, 孙予罕. Ru基氮还原电催化剂性能调控策略[J]. 化工学报, 2023, 74(6): 2264-2280.