核壳结构Co3O4@MnOx整体式催化剂的碳烟催化燃烧性能

徐大为; 张家琳; 高越; 李新刚

doi:10.19906/j.cnki.JFCT.2023057

核壳结构Co₃O₄@MnO_x整体式催化剂的碳烟催化燃烧性能

doi: 10.19906/j.cnki.JFCT.2023057

化学工程联合国家重点实验室天津化学化工协同创新中心天津市应用催化科学与工程重点实验室天津大学化工学院, 天津 300354

基金项目: 国家自然科学基金 (21878213)资助

详细信息

通讯作者:
Tel:13512925257, E-mail: xingang_li@tju.edu.cn

中图分类号: TQ448.21
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出版历程
- 收稿日期: 2023-06-25
- 修回日期: 2023-07-01
- 录用日期: 2023-07-03
- 网络出版日期: 2023-09-01

Catalytic soot combustion performance of core-shell Co₃O₄@MnO_x monolithic catalyst

State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin Key Laboratory of Applied Catalysis Science and Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300354, China

Funds: The project was supported by National Natural Science Foundation of China (21878213)

摘要

摘要: 采用两步水热法在泡沫镍基底上合成了具有纳米棒形貌的 Co₃O₄@MnO_x 整体式催化剂，通过X射线衍射、X射线能谱分析、氢气-程序升温还原、X射线光电子能谱、拉曼光谱和碳烟-程序升温还原等手段对催化剂进行表征，在微型固定床反应器上评价了其催化碳烟燃烧性能，通过等温动力学实验探究了催化剂的本征活性。结果表明，Co₃O₄@MnO_x 催化剂呈现了以 Co₃O₄ 为核、以 MnO_x 为壳的核壳结构。与催化剂 Co-NW 相比，Co₃O₄@MnO_x 催化剂中 Co₃O₄ 与 MnO_x 之间的相互作用使其表面产生了更多高价物种 Mn^{4 +} 和 Mn^{3 +} 以及更多的表面氧空位，其氧化还原性能提高，催化剂的活性氧物种数量增加了两倍，催化性能得到改善，在 NO 存在的反应气氛中使碳烟起燃温度降低148 ℃。此外，相比催化剂 Co-NW，Co₃O₄@MnO_x 催化剂使碳烟燃烧反应的活化能从113.6 kJ/mol降低至102.2 kJ/mol，催化剂的本征活性提高了两倍。
- 碳烟燃烧 /
- 钴锰氧化物 /
- 整体式催化剂 /
- 核壳结构
Abstract: The Co₃O₄@MnO_x monolithic catalyst with nanorod morphology was synthesized on nickel foam by a two-step hydrothermal process and characterized by XRD, EDS-mapping, H₂-TPR, XPS, Raman and Soot-TPR. The catalytic soot combustion activities of the catalysts were investigated in a fixed-bed micro-reactor and the intrinsic activities of the catalysts were investigated by the isothermal kinetic experiments. The results reveal that the Co₃O₄@MnO_x catalyst shows a core-shell structure with Co₃O₄ as the core and MnO_x as the shell. Compared with Co-NW, there exist more high-valent state species of Mn^{4 +} and Mn^{3 +} and oxygen vacancies on the Co₃O₄@MnO_x catalyst surface due to the interaction between Co₃O₄ and MnO_x, which improve the redox performance of Co₃O₄@MnO_x. Compared with Co-NW, the active oxygen species amount of Co₃O₄@MnO_x is increased by two times, and Co₃O₄@MnO_x shows enhanced activity, which lowers the ignition temperature by 148 ℃ in the presence of NO. Also, compared with Co-NW, Co₃O₄@MnO_x decreases the activation energy of soot combustion reaction from 113.6 kJ/mol to 102.2 kJ/mol, and its intrinsic activity is increased by two times.
- soot combustion /
- cobalt and manganese oxides /
- monolithic catalysts /
- core-shell structure

HTML全文

图 1 催化剂Co₃O₄@MnO_x的合成示意图

Figure 1 Schematic diagram of the synthesis of the Co₃O₄@MnO_x catalyst

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图 2 在10 % O₂/N₂（a）和6.0×10⁻⁴ NO/10 % O₂/N₂（b）气氛下催化剂的碳烟转化率

Figure 2 Soot conversion of the catalysts in (a) 10 % O₂/N₂ and (b) 6.0×10⁻⁴ NO/10 % O₂/N₂

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图 3 （a）催化剂Co₃O₄@MnO_x在催化碳烟燃烧过程中抗水性能；（b）催化剂 Co₃O₄@MnO_x在10 % O₂/N₂气氛下经过5次Soot-TPO循环实验后的催化稳定性

Figure 3 (a) Effect of moisture on soot combustion over the Co₃O₄@MnO_x catalyst, and (b) Catalytic stability of the Co₃O₄@MnO_x in five Soot-TPO cycles in 10 % O₂/N₂

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图 4 （a）催化剂的 XRD 谱图；（b）a的部分放大图

Figure 4 (a) The XRD patterns of the catalysts, and (b) zoom-in of (a)

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图 5 催化剂（a1-a3）Co-NW和（b1-b3）Co₃O₄@MnO_x的扫描电镜照片（a1和b1）、透射电镜图（a2和b2）和高分辨透射电镜照片（a3和b3）；（c）催化剂Co₃O₄@MnO_x的TEM-EDS能谱图

Figure 5 SEM (a1 and b1), TEM (a2 and b2) and HRTEM (a3 and b3) images of (a1-a3) Co-NW and (b1-b3) Co₃O₄@MnO_x, and (c) SEM-EDS elemental mapping images of the Co₃O₄@MnO_x

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图 6 催化剂的XPS谱图

Figure 6 XPS spectra of the catalysts: (a) Co 2p, (b) Mn 3s, (c) Mn 2p and (d) O 1s

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图 7 整体式催化剂的H₂-TPR谱图

Figure 7 H₂-TPR curves of the catalysts

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图 8 催化剂的Soot-TPR谱图

Figure 8 Soot-TPR curves of the catalysts

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图 9 催化剂的Raman光谱谱图

Figure 9 Raman spectra of the catalysts

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图 10 催化剂在等温催化碳烟燃烧过程中厌氧阶段的CO₂浓度随时间的变化

Figure 10 CO₂ concentrations as a function of time over the catalysts before and after O₂ is removed from the reactant

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图 11 催化剂在等温碳烟燃烧反应中的阿伦尼乌斯曲线

Figure 11 Arrhenius plots of isothermal soot combustion

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表 1 在有/无6.0×10⁻⁴ NO存在时催化剂的碳烟燃烧活性

Table 1 Activities of the catalysts in the presence or absence of 6.0×10⁻⁴ NO for soot combustion

Catalyst	t₁₀/℃		t₅₀/℃		s_CO₂
Catalyst	0	6.0×10⁻⁴	0	6.0×10⁻⁴	0	6.0×10⁻⁴
Blank	475	447	562	542	55	60
Ni-foam	428	396	517	475	100	100
Co-NW	400	337	461	387	100	100
Co₃O₄@MnO_x	321	299	371	334	100	100

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表 2 松接触模式下，催化剂的碳烟燃烧活性

Table 2 Catalytic activities of catalysts for soot combustion in loose contact

Catalyst	Soot/catalyst weight ratio	Reaction gas	Characteristic temperature (t₅₀ or t_m)
Co₃O₄@MnO_x (this work)	1/10	10% O₂ + 6.0×10⁻⁴ NO	334
Co₃O₄-C^[10]	1/10	5% O₂ + 2.5×10⁻³ NO	421
K_0.1Co^[21]	1/9	8% O₂ + 5.0×10⁻⁴ NO	365
5KCo-NW*^[16]	1/10	5% O₂ + 6.0×10⁻⁴ NO	324
Mn₂O₃-C^[11]	1/10	5% O₂ + 2.5×10⁻³ NO	435
3DOM Mn_0.3Ce_0.7O_δ^[22]	1/10	5% O₂ + 2.0×10⁻³ NO	356
Mn₃O₄-HNS^[23]	1/10	5% O₂ + 2.5×10⁻³ NO	408
K-OMS-2/SiO₂-50^[24]	1/10	10% O₂ + 2.0×10⁻³ NO	328
K-Mn/3DOM La_0.8Ce_0.2FeO₃^[25]	1/9	5% O₂ + 5.0×10⁻⁴ NO	377
3DOMM PdCo₂O₄/CZO^[26]	1/9	5% O₂ + 2.0×10⁻³ NO	367
0.6Co/Fe-NF*^[27]	1/10	5% O₂ + 3.0×10⁻⁴ NO	382
*These targets are monolithic catalysts

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表 3 催化剂的元素含量和表面组成

Table 3 Elemental content and surface composition of the catalysts

Catalyst	Total Co/Mn ratio ^a	Surface Co/Mn ratio ^b	Co^{2 +} /Co^{3 +}	O_ads/O_latt
Co₃O₄-NW	−	−	0.5	0.66
Co₃O₄@MnO_x	0.91	0.037	−	0.81
^a: Obtained by ICP；^b: Obtained by XPS

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表 4 催化剂的反应速率、活性氧数量（O*）和 TOF 值

Table 4 The reaction rate, active oxygen (O*) amounts, and TOF of the catalysts

Catalyst	v	O* amount	TOF
Catalyst	mol g⁻¹ s⁻¹ × 10⁻⁷	mol g⁻¹ × 10⁻⁵	s⁻¹ × 10⁻³
Co-NW	4.7	5.6	0.8
Co₃O₄@MnO_x	19.5	11.5	1.7

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参考文献(41)

[1]	王磊, 曹春梅, 邢令利, 等. 锰铈相互作用对催化碳烟燃烧性能的影响[J]. 化学工业与工程,2018,35(4):32−37. doi: 10.13353/j.issn.1004.9533.20161063 WANG Lei, CAO Chun-mei, XING Ling-li, et al. The effect of manganese/cerium interactions in catalytic soot combustion[J]. Chem Ind Eng,2018,35(4):32−37. doi: 10.13353/j.issn.1004.9533.20161063
[2]	PENG C, YU D, ZHANG C, et al. Alkali/alkaline-earth metal-modified MnO_x supported on three-dimensionally ordered macroporous-mesoporous Ti_xSi_1-xO₂ catalysts: Preparation and catalytic performance for soot combustion[J]. J Environ Sci,2023,125:82−94. doi: 10.1016/j.jes.2021.10.029
[3]	DHAL G C, MOHAN D, PRASAD R. Preparation and application of effective different catalysts for simultaneous control of diesel soot and NO_x emissions: An overview[J]. Catal Sci Technol,2017,7(9):1803−1825. doi: 10.1039/C6CY02612E
[4]	REN W, DING T, YANG Y X, et al. Identifying oxygen activation/oxidation sites for efficient soot combustion over silver catalysts interacted with nanoflower-like hydrotalcite-derived CoAlO metal oxides[J]. ACS Catal,2019,9(9):8772−8784. doi: 10.1021/acscatal.9b01897
[5]	YU Q, XIONG J, LI Z, et al. Optimal exposed crystal facets of α-Mn₂O₃ catalysts with enhancing catalytic performance for soot combustion[J]. Catal Today,2021,376:229−238. doi: 10.1016/j.cattod.2020.05.039
[6]	PENG R, LI S, SUN X, et al. Size effect of Pt nanoparticles on the catalytic oxidation of toluene over Pt/CeO₂ catalysts[J]. Appl Catal B,2018,220:462−470. doi: 10.1016/j.apcatb.2017.07.048
[7]	LEE J H, JO D Y, CHOUNG J W, et al. Roles of noble metals (M = Ag, Au, Pd, Pt and Rh) on CeO₂ in enhancing activity toward soot oxidation: Active oxygen species and DFT calculations[J]. J Haz Mat,2021,403:124085. doi: 10.1016/j.jhazmat.2020.124085
[8]	RONG S P, ZHANG P Y, LIU F, et al. Engineering crystal facet of α-MnO₂ nanowire for highly efficient catalytic oxidation of carcinogenic airborne formaldehyde[J]. ACS Catal,2018,8:3435−3446. doi: 10.1021/acscatal.8b00456
[9]	LEGUTKO P, STELMACHOWSKI P, YU X H, et al. Catalytic soot combustion-General concepts and alkali promotion[J]. ACS Catal,2023,13:3395−3418. doi: 10.1021/acscatal.2c05994
[10]	ZHAI G J, WANG J G, CHEN Z M, et al. Boosting soot combustion efficiency of Co₃O₄ nanocrystals via tailoring crystal facets[J]. Chem Eng J,2018,337:488−498. doi: 10.1016/j.cej.2017.12.141
[11]	CHENG L, MEN Y, WANG J G, et al. Crystal facet-dependent reactivity of α-Mn₂O₃ microcrystalline catalyst for soot combustion[J]. Appl Catal B,2017,204:374−384. doi: 10.1016/j.apcatb.2016.11.041
[12]	CAO C M, YANG H, XIAO J Y, et al. Catalytic diesel soot elimination over potassium promoted transition metal oxide (Co/Mn/Fe) nanosheets monolithic catalysts[J]. Fuel,2021,305(9):121446.
[13]	YU Y F, MENG M, DAI F F. The monolithic lawn-like CuO-based nanorods array used for diesel soot combustion under gravitational contact mode[J]. Nanoscale,2013,5(3):904−909. doi: 10.1039/C2NR33269H
[14]	ZHAO P, FENG N J, FANG F, et al. Surface acid etching for efficient anchoring of potassium on 3DOM La_0.8Sr_0.2MnO₃ catalyst: An integration strategy for boosting soot and NO_x simultaneous elimination[J]. J Haz Mat, 2021, 409: 124916.
[15]	XING L L, YANG Y X, CAO C M, et al. Decorating CeO₂ nanoparticles on Mn₂O₃ nanosheets to improve catalytic soot combustion[J]. ACS Sustain Chem Eng,2018,6(12):16544−16554. doi: 10.1021/acssuschemeng.8b03645
[16]	CAO C M, XING L L, YANG Y X, et al. Diesel soot elimination over potassium-promoted Co₃O₄ nanowires monolithic catalysts under gravitation contact mode[J]. Appl Catal B,2017,218:32−45. doi: 10.1016/j.apcatb.2017.06.035
[17]	ZHAO Y, HU L F, ZHAO S Y, et al. Preparation of MnCo₂O₄@Ni(OH)₂ core-shell flowers for asymmetric supercapacitor materials with ultrahigh specific capacitance[J]. Adv Funct Mater,2016,26(23):4085−4093. doi: 10.1002/adfm.201600494
[18]	XU K B, ZOU R J, LI W Y, et al. Design and synthesis of 3D interconnected mesoporous NiCo₂O₄@Co_xNi_1-x(OH)₂ core-shell nanosheet arrays with large areal capacitance and high rate performance for supercapacitors[J]. J Mater Chem A,2014,2(26):10090−10097. doi: 10.1039/c4ta01489h
[19]	KONG D Z, LUO J S, WANG Y L, et al. Three-dimensional Co₃O₄@MnO₂ hierarchical nanoneedle arrays: Morphology control and electrochemical energy storage[J]. Adv Funct Mater,2014,24(24):3815−3826. doi: 10.1002/adfm.201304206
[20]	ZHANG Z L, ZHANG Y X, WANG Z P, et al. Catalytic performance and mechanism of potassium-promoted Mg-Al hydrotalcite mixed oxides for soot combustion with O₂[J]. J Catal,2010,271(1):12−21. doi: 10.1016/j.jcat.2010.01.022
[21]	SHANG Z, SUN M, CHE X, et al. The existing states of potassium species in K-doped Co₃O₄ catalysts and their influence on the activities for NO and soot oxidation[J]. Catal Sci Technol,2017,7(20):4710−4719. doi: 10.1039/C7CY01444A
[22]	YU X H, LI J M, WEI Y C, et al. Three dimensionally ordered macroporous Mn_xCe_1–xO_δ and Pt/Mn_0.5Ce_0.5O_δ catalysts: Synthesis and catalytic performance for soot oxidation[J]. Ind Eng Chem Res,2014,53(23):9653−9664. doi: 10.1021/ie500666m
[23]	JI F, MEN Y, WANG J G, et al. Promoting diesel soot combustion efficiency by tailoring the shapes and crystal facets of nanoscale Mn₃O₄[J]. Appl Catal B,2018,242:227−237.
[24]	YU X H, ZHAO Z, WEI Y C, et al. Ordered micro/macro porous K-OMS-2/SiO₂ nanocatalysts: Facile synthesis, low cost and high catalytic activity for diesel soot combustion[J]. Sci Rep,2017,7:43894. doi: 10.1038/srep43894
[25]	FENG N J, CHEN C, MENG J, et al. K-Mn supported on three-dimensionally ordered macroporous La_0.8Ce_0.2FeO₃ catalysts for the catalytic combustion of soot[J]. Appl Surf Sci,2017,399:114−122. doi: 10.1016/j.apsusc.2016.12.066
[26]	XIONG J, WU Q Q, MEI X L, et al. Fabrication of spinel-type Pd_xCo_3-xO₄ binary active sites on 3D ordered meso-macroporous Ce-ZrO₂ with enhanced activity for catalytic soot oxidation[J]. ACS Catal,2018,8(9):7915−7930. doi: 10.1021/acscatal.8b01924
[27]	CAO C M, LI X G, ZHA Y Q, et al. Crossed ferric oxide nanosheets supported cobalt oxide on 3-dimensional macroporous Ni foam substrate used for diesel soot elimination under self-capture contact mode[J]. Nanoscale,2016,8(11):5857−5864. doi: 10.1039/C5NR05310B
[28]	ZHAO S, HU F Y, LI J H. Hierarchical core-shell Al₂O₃@Pd-CoAlO microspheres for low-temperature toluene combustion[J]. ACS Catal,2016,6:3433−3441. doi: 10.1021/acscatal.6b00144
[29]	LIU Y, XU J, LI H R, et al. Rational design and in situ fabrication of MnO₂@NiCo₂O₄ nanowire arrays on Ni foam as high-performance monolith de-NO_x catalysts[J]. J Mater Chem A,2015,3:11543−11553. doi: 10.1039/C5TA01212K
[30]	WANG C L, WANG D D, YANG Y, et al. Enhanced CO oxidation on CeO₂/Co₃O₄ nanojunctions derived from annealing of metal organic frameworks[J]. Nanoscale,2016,8(47):19761−19768. doi: 10.1039/C6NR07725K
[31]	JIANG M, ABUSHRENTA N, Wu X C, et al. Investigation for the synthesis of hierarchical Co₃O₄@MnO₂ nanoarrays materials and their application for super-capacitor[J]. J Mater Sci:Mater Electron,2017,28:1281−1287. doi: 10.1007/s10854-016-5656-1
[32]	FEDYNA M, LEGUTKO P, GRYBOS J, et al. Multiple doping of cryptomelane catalysts by Co, Cu, Ag and Ca for efficient soot oxidation and its effect on NO₂ formation and SO₂ resistance[J]. Fuel,2023,348:128553. doi: 10.1016/j.fuel.2023.128553
[33]	DAI W Y, LI Z H, LI C C, et al. Revealing the effects of preparation methods over Ce-MnO_x catalysts for soot combustion: Physicochemical properties and catalytic performance[J]. J Ind Eng Chem,2023,121:15−26. doi: 10.1016/j.jiec.2023.01.013
[34]	MANE R, KIM H, HAN K, et al. Pivotal role of MnO_x physicochemical structure in soot oxidation activity[J]. Fuel,2023,346:128287. doi: 10.1016/j.fuel.2023.128287
[35]	TANG W X, XIAO W, Wang S B, et al. Boosting catalytic propane oxidation over PGM-free Co₃O₄ nanocrystal aggregates through chemical leaching: A comparative study with Pt and Pd based catalysts[J]. Appl Catal B,2018,226:585−595. doi: 10.1016/j.apcatb.2017.12.075
[36]	ZHU Z Z, LU G Z, ZHANG Z G, et al. Highly active and stable Co₃O₄/ZSM-5 catalyst for propane oxidation: Effect of the preparation method[J]. ACS Catal,2013,3(6):1154−1164. doi: 10.1021/cs400068v
[37]	TANG W X, Wu X F, Li S D, et al. Porous Mn-Co mixed oxide nanorod as a novel catalyst with enhanced catalytic activity for removal of VOCs[J]. Catalysis Commun,2014,56:134−138. doi: 10.1016/j.catcom.2014.07.023
[38]	ZHAO S, LI K Z, JIANG S, et al. Pd-Co based spinel oxides derived from Pd nanoparticles immobilized on layered double hydroxides for toluene combustion[J]. Appl Catal B,2016,181:236−248. doi: 10.1016/j.apcatb.2015.08.001
[39]	ZHAO K, LI J M, WANG L Y, et al. Preparation of cordierite monolith catalysts with the coating of K-modified spinel MnCo₂O₄ oxide and their catalytic performances for soot combustion[J]. Catalysts,2022,12(3):295. doi: 10.3390/catal12030295
[40]	GAO Q, RANJAN C, PAVLOVIC Z, et al. Enhancement of stability and activity of MnO_x/Au electrocatalysts for oxygen evolution through adequate electrolyte composition[J]. ACS Catal,2015,5:7265−7275. doi: 10.1021/acscatal.5b01632
[41]	HONG F, YUE B B, HIRAO N, et al. Significant improvement in Mn₂O₃ transition metal oxide electrical conductivity via high pressure[J]. Nature,2017,7:1−7.