负载型CuMn2O4催化剂同时去除甲苯与NOx性能及机理研究

刘旭; 黄妍; 赵令葵; 李思密; 陶泓帆; 饶思敏; 朱洪

doi:10.19906/j.cnki.JFCT.2023024

负载型CuMn₂O₄催化剂同时去除甲苯与NO_x性能及机理研究

doi: 10.19906/j.cnki.JFCT.2023024

湘潭大学环境与资源学院, 湖南湘潭411105

基金项目: 湖南省教育厅科研项目（22A0129）和国家自然科学基金（52270107）资助

详细信息

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E-mail: xtuhy@163.com

中图分类号: X701
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出版历程
- 收稿日期: 2023-03-08
- 修回日期: 2023-03-22
- 录用日期: 2023-03-24
- 网络出版日期: 2023-04-06
- 刊出日期: 2023-12-05

Study on performance and mechanism of CuMn₂O₄ supported catalyst for simultaneous removal of toluene and NO_x

College of Environment and Resources, Xiangtan University, Xiangtan 411105, China

Funds: The project was supported by Hunan Provincial Department of Education funded research projects (22A0129), Supported by the National Natural Science Foundation of China (52270107)

摘要

摘要: 本研究使用低温溶胶凝胶自燃法制备了不同载体负载的CuMn₂O₄/MO₂(M=Mn、Ti、Ce)催化剂，并对其同时去除甲苯和NO_x的性能进行了评价。结果表明，CeO₂载体的加入可显著缓解CuMn₂O₄上甲苯氧化与NH₃-SCR的相互抑制，因此，CuMn₂O₄/CeO₂催化剂表现出最优异的甲苯与NO_x同时去除效率。通过BET、XRD、NH₃-TPD、O₂-TPD及结合XPS与in-situ DRIFTs对催化剂的物化性质及CuMn₂O₄同时去除甲苯与NO_x的反应机理进行了分析。结果表明，CeO₂的引入提高了催化剂中Mn^{4 +}/Mn^{n +}的占比，促使CuMn₂O₄/CeO₂催化剂形成表面丰富的酸性位点和氧空位。此外，Cu、Mn和Ce之间的强相互作用加速电子转移，增强了Cu⁺ + Ce^{4 +} ↔Cu^{2 +} + Ce^{3 +}、Mn^{4 +} + Ce^{3 +} ↔Mn^{3 +} + Ce^{4 +}的氧化还原循环。In-situ DRIFTs证实了CuMn₂O₄催化剂上NH₃-SCR反应遵循Langmuir-Hinshelwood机制，甲苯的氧化遵循Mars-van Krevelen机制。因此，CeO₂作为载体的CuMn₂O₄/CeO₂催化剂优异的氧化还原能力促使甲苯的完全氧化，表现出优异的甲苯与NO_x同时去除能力。本工作可为同时消除甲苯和NO_x的催化剂开发提供指导。
- 负载型催化剂 /
- 催化氧化 /
- NH₃-SCR /
- NO /
- 甲苯
Abstract: In this study, CuMn₂O₄/MO₂(M=Mn, Ti, Ce) catalysts with different support loads were prepared by sol-gel spontaneous combustion at low temperature, and the removal performance of toluene and NO_x was evaluated. The results showed that the addition of CeO₂ carrier could significantly alleviate the mutual inhibition of toluene oxidation and NH₃-SCR over CuMn₂O₄. Therefore, CuMn₂O₄/CeO₂ catalyst showed the best removal efficiency of toluene and NO_x simultaneously. The physicochemical properties of the catalyst and the reaction mechanism of CuMn₂O₄ were analyzed by BET, XRD, NH₃-TPD, O₂-TPD and combined XPS and in-situ DRIFTs. The results showed that the introduction of CeO₂ increased the proportion of Mn^{4 +}/Mn^{n +} in the catalyst, and promoted the formation of rich acid sites and oxygen vacancies on the surface of CuMn₂O₄/CeO₂ catalyst. In addition, the strong interaction between Cu, Mn and Ce accelerated electron transfer and enhance the redox cycle for Cu⁺ + Ce^{4 +} ↔Cu^{2 +} + Ce^{3 +}、Mn^{4 +} + Ce^{3 +} ↔Mn^{3 +} + Ce^{4 +}. It has been confirmed by in-situ DRIFTs that NH₃-SCR reaction on CuMn₂O₄ catalyst follows Langmuir-Hinshelwood mechanism and oxidation of toluene follows Mars-van Krevelen mechanism. Therefore, CuMn₂O₄/CeO₂ catalyst with CeO₂ as the support has excellent reoxidation ability to promote the complete oxidation of toluene, so it shows excellent removal ability of toluene and NO_x simultaneously. This work can provide guidance for the development of catalysts for simultaneous removal of toluene and NO_x.
- supported catalyst /
- catalytic oxidation /
- NH₃-SCR /
- NO /
- toluene

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FIG. 2812. FIG. 2812.

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图 1 实验装置示意图

Figure 1 Schematic diagram of experimental apparatus

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图 2 CuMn₂O₄/MO₂（M=Mn、Ce、Ti）催化剂NH₃-SCR还原NO（a）, 单独氧化甲苯（b）

Figure 2 CuMn₂O₄/MO₂ (M=Mn, Ce, Ti) catalyst NH₃-SCR reduction of NO (a), alone oxidized toluene (b)

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图 3 CuMn₂O₄/MO₂（M=Mn、Ce、Ti）催化剂协同处理NO（a）, 协同处理甲苯（b）

Figure 3 CuMn₂O₄/MO₂ (M=Mn, Ce, Ti) catalyst synergistic treatment of NO (a), synergistic treatment of toluene (b)

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图 4 CuMn₂O₄/CeO₂的稳定性测试

Figure 4 Stability test of CuMn₂O₄/CeO₂

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图 5 催化剂吸附等温线

Figure 5 Catalyst adsorption isotherms

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图 6 负载前后尖晶石的XRD谱图

Figure 6 Spinel XRD before and after loading

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图 7 不同载体负载尖晶石催化剂的NH₃-TPD谱图

Figure 7 NH₃-TPD spectra of spinel catalysts supported by different carriers

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图 8 不同载体负载尖晶石催化剂的O₂-TPD谱图

Figure 8 O₂-TPD spectra of spinel catalysts supported by different carriers

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图 9 不同载体催化剂的XPS谱图

Figure 9 XPS spectra of different supported catalysts

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图 10 CuMn₂O₄在300 ℃吸附时间原位光谱研究

Figure 10 In-situ spectroscopic study of CuMn₂O₄ adsorption time at 300 ℃ (a): Adsorption of toluene and NO after toluene adsorption; (b): Toluene is oxidized into toluene; (c): Toluene is oxidized into NH₃-SCR

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图 11 甲苯与NO的同时去除示意图

Figure 11 Diagram of simultaneous removal of toluene and NO

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表 1 催化剂的比表面积以及孔容孔径

Table 1 Catalyst specific surface area

Species	Surface area /（m²·g⁻¹）	Pore volume /（cm³·g⁻¹）	Mean pore size /nm
CuMn₂O₄	1.61	0.00249	5.99
CuMn₂O₄/MnO₂	18.52	0.04165	7.89
CuMn₂O₄/TiO₂	19.24	0.04759	8.32
CuMn₂O₄/CeO₂	23.76	0.05247	8.84

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表 2 催化剂的XPS表面元素比值

Table 2 XPS of surface element ratio

Species	O Atomic/%			Binding energy/eV		Cu⁺/Cu^{2 +}	Mn^{4 +}/Mn^{3 +}	Atomic /%
Species	O_ads	O_latt	O_ads/O_lat	O_ads	O_lat			Cu	Mn	O	M
CuMn₂O₄	52.54	47.46	1.10	531.7	530.1	0.57	0.47	7.16	26.29	66.55
CuMn₂O₄/MnO₂	47.85	52.15	0.91	531.8	530.4	0.82	0.50	6.01	26.81	67.17
CuMn₂O₄/TiO₂	42.20	57.80	0.73	532.4	530.9	0.22	0.22	6.56	23.06	65.24	5.14
CuMn₂O₄/CeO₂	35.11	64.89	0.54	531.0	529.6	0.28	0.78	5.51	23.66	65.75	5.08

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参考文献(30)

[1]	XIAO G, GUO Z, LIN B. Cu-VWT catalysts for synergistic elimination of NO_x and volatile organic compounds from coal-fired flue gas[J]. Environ Sci Technol,2022,56(14):10095−10104. doi: 10.1021/acs.est.2c02083
[2]	LIU H, CHEN J, WANG Y, YIN R, YANG W, WANG G, SI W, PENG Y, LI J. Interaction mechanism for simultaneous elimination of nitrogen oxides and toluene over the bifunctional CeO₂-TiO₂ mixed oxide catalyst[J]. Environ Sci Technol,2022,56(7):4467−4476. doi: 10.1021/acs.est.1c08424
[3]	CHEN Y, CHEN Z, ZHANG C, LIN C, TANG J, LIAO Y, MA X. Multiple pollutants control of NO, benzene and toluene from coal-fired plant by Mo/Ni impregnated TiO₂-based NH₃-SCR catalyst: A DFT supported experimental study[J]. Appl Surf Sci,2022,599:153986. doi: 10.1016/j.apsusc.2022.153986
[4]	FANG D, XIE J, MEI D, ZHANG Y, HE F, LIU X, LI Y. Effect of CuMn₂O₄ spinel in Cu-Mn oxide catalysts on selective catalytic reduction of NO_x with NH₃ at low temperature[J]. RSC Adv,2014,4(49):25540−25551.
[5]	ZHANG Y, LI Y, ZENG Z, HU J, HUANG Z. Promotion mechanism of CuMn₂O₄ modification with NaOH on toluene oxidation: Boosting the ring-opening of benzoate[J]. Fuel,2022,314:122747.
[6]	PAN H, CHEN Z, MA M, GUO T, LING X, ZHENG Y, HE C, CHEN J. Mutual inhibition mechanism of simultaneous catalytic removal of NO_x and toluene on Mn-based catalysts[J]. J Colloid Interface Sci,2022,607:1189−1200.
[7]	YE L, LU P, CHEN X, FANG X, PENG P, LI Y, HUANG J, BAO H. The deactivation mechanism of toluene on MnO_x-CeO₂ SCR catalyst[J]. Appl Catal B: Environ,2020,277:119257.
[8]	LI Z, GAO, WANG Q. The influencing mechanism of NH₃ and NO_x addition on the catalytic oxidation of toluene over Mn₂Cu₁Al₁O_x catalyst[J]. J Cleaner Prod,2022,348:131152. doi: 10.1016/j.jclepro.2022.131152
[9]	ZHOU X, LIAO W, CAI N, ZHANG H, YANG H, SHAO J. Experiment and mechanism investigation on simultaneously catalytic reduction of NO_x and oxidation of toluene over MnO_x/Cu-SAPO-34[J]. Appl Surf Sci,2023,611:155628. doi: 10.1016/j.apsusc.2022.155628
[10]	张娜, 黄妍, 张俊丰, 赵令葵, 李思密, 陶泓帆, 伍云凡. 负载型LaCoO₃/MO₂催化氧化甲苯与NO的性能研究[J]. 燃料化学学报,2022,50(7):868−876. ZHANG Na, HUANG Yan, ZHANG Jun-feng, ZHAO Ling-kui, LI Si-mi, TAO Hong-fan, WU Yun-fan. Catalytic oxidation of toluene and NO by supported LaCoO₃/MO₂[J]. J Fuel Chem Technol,2022,50(7):868−876.
[11]	WANG Z, LIU J, YANG Y, YU Y, YAN X, ZHANG Z. AMn₂O₄(A=Cu, Ni and Zn) sorbents coupling high adsorption and regeneration performance for elemental mercury removal from syngas[J]. J Haz Mater,2020,388:121738. doi: 10.1016/j.jhazmat.2019.121738
[12]	KANG M, PARK E D, KIM J M, YIE J. Cu-Mn mixed oxides for low temperature NO reduction with NH₃[J]. Catal Today,2006,111(3/4):236−241. doi: 10.1016/j.cattod.2005.10.032
[13]	FANG R, LIU F, LIU J, LI Y. Experimental and theoretical insights into the reaction mechanism of spinel CuMn₂O₄ with CO in chemical-looping combustion[J]. Appl Surf Sci,2021,561:150065.
[14]	ZHANG Y, LI Y, ZENG Z, HU J, HOU Y, HUANG Z. Synergically engineering Cu⁺ and oxygen vacancies in CuMn₂O₄ catalysts for enhanced toluene oxidation performance[J]. Mol Catal,2022,517:112043.
[15]	蒋露. SO₂、H₂O对镧铁系钙钛矿催化剂协同催化氧化NO和甲苯的影响机制研究[D]. 湘潭: 湘潭大学, 2021. JIANG Lu. Effect mechanism of SO₂ and H₂O on synergistic catalytic oxidation of NO and Toluene with lanthanide perovskite catalyst[D]. Xiangtan: Xiangtan University, 2021.
[16]	LIN B, GUO Z, LI J, XIAO G, YE D, YUN H. V-Cu bimetallic oxide supported catalysts for synergistic removal of toluene and NO_x from coal-fired flue gas: The crucial role of support[J]. Chem Eng J,2023,458:141443.
[17]	YANG J, HU S, FANG Y, HOANG S, GOU Y. Oxygen vacancy promoted O₂ activation over perovskite oxide for low-temperature CO oxidation[J]. ACS Catal,2019,9(11):9751−9763. doi: 10.1021/acscatal.9b02408
[18]	SHI C, YIN D, LI J. Novel LaMnNi mixed metal oxides catalysts for selective catalytic oxidation of NO[C]//The 2019 North American Catalysis Society Meeting, 2019. NAM, 262019.
[19]	HEREDIA L, COLOMBO E, QUAINO P, COLLINS S. Toluene adsorption on CeO₂ (111) studied by FTIR and DFT[J]. Top Catal,2022,65(7/8):934−943. doi: 10.1007/s11244-022-01625-2
[20]	WANG J, XING Y, SU W, LI K, ZHANG W. Bifunctional Mn-Cu-CeO_x/γ-Al₂O₃ catalysts for low-temperature simultaneous removal of NO_x and CO[J]. Fuel,2022,321:124050.
[21]	ZHANG X, LV X, BI F. Highly efficient Mn₂O₃ catalysts derived from Mn-MOFs for toluene oxidation: The influence of MOFs precursors[J]. Mol Catal,2020,482:110707.
[22]	LI Z, GAO Y, WANG Q. The influencing mechanism of NH₃ and NO_xaddition on the catalytic oxidation of toluene over Mn₂Cu₁Al₁O_x catalyst [J]. J Clean Prod, 2022, 348: 131152 .
[23]	ZHONG J, ZENG Y, ZHANG M, FANG W, XIAO D, WU J, CHEN P, FU M, YE D. Toluene oxidation process and proper mechanism over Co₃O₄ nanotubes: Investigation through in-situ DRIFTS combined with PTR-TOF-MS and quasi in-situ XPS[J]. Chem Eng J,2020,397:125375. doi: 10.1016/j.cej.2020.125375
[24]	LU J, ZHONG J, REN Q, LI J, SONG L, MO S, ZHANG M, CHEN P, FU M, YE D. Construction of Cu-Ce interface for boosting toluene oxidation: Study of Cu-Ce interaction and intermediates identified by in situ DRIFTS[J]. Chin Chem Lett,2021,32(11):3435−3439. doi: 10.1016/j.cclet.2021.05.029
[25]	BESSELMANN S, LÖFFLER E, MUHLER M. On the role of monomeric vanadyl species in toluene adsorption and oxidation on V₂O₅/TiO₂ catalysts: A Raman and in situ DRIFTS study[J]. J Mol Catal A: Chem,2000,162(1/2):401−411. doi: 10.1016/S1381-1169(00)00307-1
[26]	ZHANG X, LI H, SONG Z. In situ DRIFT spectroscopy study into the reaction mechanism of toluene over CeMo catalysts[J]. JECE,2022,10(6):108895.
[27]	CHEN Y, CHEN Z, ZHANG C, CHEN L, TANG J, LIAO Y, MA X. Multiple pollutants control of NO, benzene and toluene from coal-fired plant by Mo/Ni impregnated TiO₂-based NH₃-SCR catalyst: A DFT supported experimental study[J]. Appl Surf Sci,2022,599:1539869.
[28]	JIA Y, JIANG J, ZHENG R, GUO L, GU M. Insight into the reaction mechanism over PMoA for low temperature NH₃-SCR: A combined In-situ DRIFTs and DFT transition state calculations[J]. J Haz Mater,2021,412:125258. doi: 10.1016/j.jhazmat.2021.125258
[29]	YANG Y, LIU J, LIU F, WANG Z. Reaction mechanism for NH₃-SCR of NO_x over CuMn₂O₄ catalyst[J]. Chem Eng J,2019,361:578−587. doi: 10.1016/j.cej.2018.12.103
[30]	ZHAO L, YANG Y, LIU J, DING J. Mechanistic insights into benzene oxidation over CuMn₂O₄ catalyst[J]. J Haz Mater,2022,431:128640. doi: 10.1016/j.jhazmat.2022.128640