Investigation of Co-doped Mn oxide catalyst for NH3-SCR activity and SO2/H2O resistance
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摘要: 采用共沉淀法制备了一系列不同物质的量比的钴掺杂锰氧化物催化剂,并对其进行了系统表征。讨论了钴掺杂锰的氧化物催化剂的NH3-SCR催化活性和抗水抗硫性能。结果表明,锰钴物质的量比为1∶1的Co(1)-MnOx催化剂的催化性能最好,在100−275 ℃时实现了大于90%的NOx转化率,并且耐水性和耐硫性较好。Co(1)-MnOx催化剂呈现出球状结构,拥有相对较大的表面积。钴掺杂锰增加了催化剂表面的高价金属离子和化学吸附氧含量。Co(1)-MnOx催化剂具有丰富的活性物种和酸性位点,降低了催化剂的表观活化能。Abstract: A series of Co-doped Mn oxide catalysts with different Co/Mn molar ratios were prepared by co-precipitation method, which was systematically characterized by XRD, SEM, H2-TPR and NH3-TPD etc. Co-doped Mn oxide catalysts are evaluated for NH3-SCR activity and resistance to SO2 and/or H2O, and the Co(1)-MnOx catalyst with Mn/Co molar ratio of 1∶1 performs the best catalytic performance, which achieved higher than 90% NOx conversion in the temperature range of 100−275 °C and possessed better SO2 and H2O resistance. The Co(1)-MnOx catalyst presented a sphere-like structure possessing a relatively large surface area. Doping of cobalt greatly improved the high-valent metal ions and chemisorbed oxygen content of Co(1)-MnOx catalyst surface, and the catalyst possessed abundant active species and acid sites and apparent activation energy of the catalyst was reduced, which makes Co(1)-MnOx a highly effective NH3-SCR catalyst.
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Key words:
- selective catalytic reduction /
- cobalt-doping /
- manganese /
- synergistic effect
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Table 1 MnOx, CoOx and Co(1)-MnOx catalysts structural parameters
Catalyst BET surface area/(m2·g–1) Average pore diameter/nm Pore volume/ (cm3·g–1) MnOx 131 3.72 0.23 Co(1)-MnOx 158 6.28 0.31 CoOx 117 6.80 0.29 Table 2 Surface element concentrations and relative atomic concentrations of Co(1)-MnOx and MnOx catalysts
Catalyst Surface atoms concentration/% Relative concentration ratios/% O Mn Co Oα/(Oα+Oβ) Mn4+/Mn Co3+/Co Co(1)-MnOx 70.54 16.48 12.97 58.20 37.34 33.26 MnOx 53.95 10.42 − 49.70 33.14 − -
[1] KANG H, WANG J J, ZHENG J, CHU W, TANG C J, JI J W, REN R, WU M X, JING F L. Solvent-free elaboration of Ni-doped MnOx catalysts with high performance for NH3-SCR in low and medium temperature zones[J]. Mol Catal,2021,501:111376. doi: 10.1016/j.mcat.2020.111376 [2] WAN Y, ZHAO W, TANG Y, LI L, WANG H, CUI Y, GU J, LI Y, SHI J. Ni-Mn bi-metal oxide catalysts for the low temperature SCR removal of NO with NH3[J]. Appl Catal B: Environ,2014,148−149:114−122. [3] ANDANA T, RAPPÉ K G, GAO F, SZANYI J, PEREIRA-HERNANDEZ X, WANG Y. Recent advances in hybrid metal oxide-zeolite catalysts for low-temperature selective catalytic reduction of NOx by ammonia[J]. Appl Catal B: Environ,2021,291:120054. doi: 10.1016/j.apcatb.2021.120054 [4] CHEN S, VASILIADES M A, YAN Q, YANG G, DU X, ZHANG C, LI Y, ZHU T, WANG Q EFSTATHIOU A M. Remarkable N2-selectivity enhancement of practical NH3-SCR over Co0.5Mn1Fe0.25Al0.75Ox-LDO: The role of Co investigated by transient kinetic and DFT mechanistic studies[J]. Appl Catal B: Environ,2020,277:119186. doi: 10.1016/j.apcatb.2020.119186 [5] CHENG K, LIU J, ZHAO Z, WEI Y C, JIANG G Y, DUAN A J. Direct synthesis of V-W-Ti nanoparticle catalysts for selective catalytic reduction of NO with NH3[J]. RSC Adv,2015,5(56):45172−45183. doi: 10.1039/C5RA05978J [6] YAO X J, MA K L, ZOU W X, HE S G, AN J B, YANG F M, DONG L. Influence of preparation methods on the physicochemical properties and catalytic performance of MnOx-CeO2 catalysts for NH3-SCR at low temperature[J]. Chin J Catal,2017,38(1):146−159. doi: 10.1016/S1872-2067(16)62572-X [7] LIU J, LI G Q, ZHANG Y F, LIU X Q, WANG Y, LI Y. Novel Ce-W-Sb mixed oxide catalyst for selective catalytic reduction of NOx with NH3[J]. Appl Surf Sci,2017,401:7−16. doi: 10.1016/j.apsusc.2016.12.244 [8] SHI Y R, YI H H, GAO F, ZHAO S Z, XIE Z L, TANG X L. Evolution mechanism of transition metal in NH3-SCR reaction over Mn-based bimetallic oxide catalysts: Structure-activity relationships[J]. J Hazard Master,2021,413:125361. doi: 10.1016/j.jhazmat.2021.125361 [9] PENG Y, QU R Y, ZHANG X Y, LI J H. The relationship between structure and activity of MoO3-CeO2 catalysts for NO removal: influences of acidity and reducibility[J]. Catal Commun,2013,49(55):6215−6217. [10] WANG C Z, YANG S J, CHANG H Z, PENG Y, LI J H. Structural effects of iron spinel oxides doped with Mn, Co, Ni and Zn on selective catalytic reduction of NO with NH3[J]. J Mol Catal A: Chem,2013,376:13−21. doi: 10.1016/j.molcata.2013.04.008 [11] ZHAO Q, CHEN B B, CROCKER M, SHI C. Insights into the structure-activity relationships of highly efficient CoMn oxides for the low temperature NH3-SCR of NOx[J]. Appl Catal B: Environ,2020,277:119215. doi: 10.1016/j.apcatb.2020.119215 [12] LIU L, WANG B D, YAO X J, YANG L, JIANG W J, JIANG X. Highly efficient MnOx/biochar catalysts obtained by air oxidation for low-temperature NH3-SCR of NO[J]. Fuel,2021,283:119336. doi: 10.1016/j.fuel.2020.119336 [13] GENG Y, SHAN W P, LIU F D, YANG S J. Adjustment of operation temperature window of Mn-Ce oxide catalyst for the selective catalytic reduction of NOx with NH3[J]. J Hazard Mater,2021,405:124223. doi: 10.1016/j.jhazmat.2020.124223 [14] CHEN L Q, NIU X Y, LI Z B, DONG Y L, ZHANG Z P, YUAN F L, ZHU Y J. Promoting catalytic performances of Ni-Mn spinel for NH3-SCR by treatment with SO2 and H2O[J]. Catal Commun,2016,85:48−51. doi: 10.1016/j.catcom.2016.07.013 [15] ZHANG S B, LI H X, ZHANG A C, SUN Z J, ZHANG X M, YANG C Z, JIN L Y, SONG Z H. Selective catalytic reduction of NOx by low temperature NH3 over MnxZr1 mixed-oxide catalysts[J]. RSC Advances,2022,12:1341−1351. [16] FAN R Y, XIE J Y, YU N, CHAI Y M, DONG B. Interface design and composition regulation of cobalt-based electrocatalysts for oxygen evolution reaction[J]. Int J Hydrogen Energ,2022,47(19):10547−10572. [17] ZHU Y , XIAO X, WANG J, MA C, JIA X, QIAO W. Enhanced activity and water resistance of hierarchical flower-like Mn-Co binary oxides for ammonia-SCR reaction at low temperature[J]. Appl Surface Sci,2021,569:150989. [18] SUMMA P, ŚWIRK K, WANG Y, SAMOJEDEN B, RØNNING M, HU C, MOTAK M, COSTA P D. Effect of cobalt promotion on hydrotalcite-derived nickel catalyst for CO2 methanation[J]. Appl Mater Today,2021,25:101211. [19] JIANG H X, WANG Q Y, WANG H Q, CHEN Y F, ZHANG M F. Temperature effect on the morphology and catalytic performance of Co-MOF-74 in low-temperature NH3-SCR process[J]. Catal Commun,2016,80:24−27. doi: 10.1016/j.catcom.2016.03.013 [20] YAN Q Y, LI X Y, ZHAO Q D, CHEN G H. Shape-controlled fabrication of the porous Co3O4 nanoflower clusters for efficient catalytic oxidation of gaseous toluene[J]. J Hazard Mater,2012,209−210:385−391. [21] JIANG H, GUAN B, PENG X S, ZHAN R, LIN H, HUANG Z. Influence of synthesis method on catalytic properties and hydrothermal stability of Cu/SSZ-13 for NH3-SCR reaction[J]. Chem Eng J,2020,379:122358. doi: 10.1016/j.cej.2019.122358 [22] MENG D M, XU Q, JIAO Y, GUO Y, GUO Y, WANG L, LU G, ZHAN W. Spinel structured CoaMnbOx mixed oxide catalyst for the selective catalytic reduction of NOx with NH3[J]. Appl Catal B: Environ,2018,221:652−663. doi: 10.1016/j.apcatb.2017.09.034 [23] HU X N, HUANG L, ZHANG J P, LI H R, ZHA K W, SHI L Y, ZHANG D S. Facile and template-free fabrication of mesoporous 3D nanosphere-like MnxCo3–xO4 as highly effective catalysts for low temperature SCR of NOx with NH3[J]. J Mater Chem A,2018,6(7):2952−2963. doi: 10.1039/C7TA08000J [24] ZHANG Q L, LIU X, NING P, SONG Z X, LI H, GU J J. Enhanced performance in NOx reduction by NH3 over a mesoporous Ce-Ti-MoOx catalyst stabilized by a carbon template[J]. Catal Sci Technol,2015,5:2260−2269. doi: 10.1039/C4CY01371A [25] ZHAO K, MENG J P, LU J Y, HE Y, HUANG H Z, TANG Z C, ZHEN X P. Sol-gel one-pot synthesis of efficient and environmentally friendly iron-based catalysts for NH3 -SCR[J]. Appl Surf Sci,2018,445:454−461. doi: 10.1016/j.apsusc.2018.03.160 [26] AGUILERA D A, PEREZ A, MOLINA R, MORENO S. Cu-Mn and Co-Mn catalysts synthesized from hydrotalcites and their use in the oxidation of VOCs[J]. Appl Catal B: Environ,2011,104(1/2):144−150. doi: 10.1016/j.apcatb.2011.02.019 [27] JIANG S J, SONG S Q. Enhancing the performance of Co3O4/CNTs for the catalytic combustion of toluene by tuning the surface structures of CNTs[J]. Appl Catal B: Environ,2013,140−141:1−8. [28] HAN Y L, MU J C, LI X Y, GAO J S, TAN F, ZHAO Q D. Triple-shelled NiMn2O4 hollow spheres as an efficient catalyst for low-temperature selective catalytic reduction of NOx with NH3[J]. Catal Commun,2018,54(70):9797−9800. [29] BAI Y Z, ZHU J H, LUO H J, WANG Z F, GONG Z J, ZHAO R, WU W F, ZHANG K. Study on NH3-SCR performance and mechanism of Fe/Mn modified rare earth concentrate[J]. Mol Catal,2021,514:111665. [30] LI J, JIA L W, JIN W Y, XIA F, WANG J M. Effects of Ce-doping on the structure and NH3-SCR activity of Fe/Beta catalyst[J]. Rare Metal Mat Eng,2015,44(7):1612−1616. doi: 10.1016/S1875-5372(15)30102-8 [31] MENG D M, ZHANG W C, GUO Y, GUO Y L, LU G Z. A highly effective catalyst of Sm-MnOx for the NH3-SCR of NOx at low temperature: Promotional role of Sm and its catalytic performance[J]. ACS Catal,2017,5(10):5973−5983. [32] GAO F Y, YANG C, TANG X L, YI H H, WANG C Z. Co- or Ni-modified Sn-MnOx low-dimensional multi-oxides for high-efficient NH3-SCR De-NOx: Performance optimization and reaction mechanism[J]. J Environ Sci,2022,113:204−218. doi: 10.1016/j.jes.2021.05.032 [33] LEI Z, SHI L Y, HUANG L, ZHANG J P, ZHANG D S. Rational design of high-performance DeNOx catalysts based on MnxCo3–xO4 nanocages derived from metal-organic frameworks[J]. ACS Catal,2014,4(6):1753−1763. doi: 10.1021/cs401185c [34] ZHENG H L, SONG W Y, ZHOU Y, MA S C DENG J L, LI Y H, LIU J, ZHAO Z. Mechanistic study of selective catalytic reduction of NOx with NH3 over Mn-TiO2: A combination of experimental and DFT study[J]. J Phys Chem C,2017,36:19859−19871. [35] LIU J, MEEPRASERT J, NAMUANGRUK S, LI H R, HUANG L, MAITARAD P, SHI L Y, ZHANG D S. Facet-activity relationship of TiO2 in Fe2O3/TiO2 nanocatalysts for selective catalytic reduction of NO with NH3: In situ DRIFTs and DFT studies[J]. J Phys Chem C,2017,121(9):4970−4979. doi: 10.1021/acs.jpcc.6b11175 [36] XU L W, WANG C Z, CHANG H Z, WU Q R, ZHANG T, LI J H. New insight into SO2 poisoning and regeneration of CeO2-WO3/TiO2 and V2O5-WO3/TiO2 catalysts for low-temperature NH3-SCR[J]. Environ Sci Technol,2018,52(12):7064−7071. doi: 10.1021/acs.est.8b01990 [37] CHEN Q L, GUO R T, WANG Q S, PAN W G, YANG N Z, LU C Z, WANG S X. The promotion effect of Co doping on the K resistance of Mn/TiO2 catalyst for NH3-SCR of NO[J]. J Taiwan Inst Chem E,2016,64:116−123. doi: 10.1016/j.jtice.2016.03.045 [38] LI J Y, SONG Z X, NING P, ZHANG Q L, LIU X, LI H, HUANG Z Z. Influence of calcination temperature on selective catalytic reduction of NOx with NH3 over CeO2-ZrO2-WO3 catalyst[J]. J Rare Earth,2015,33(7):726−735. doi: 10.1016/S1002-0721(14)60477-4 [39] KRYCA J, JODŁOWSKI P J, IWANISZYN M, GIL B, KOŁODZIEJ A, ŁOJEWSKA T, ŁOJEWSKA J. Cu SSZ-13 zeolite catalyst on metallic foam support for SCR of NO with ammonia: Catalyst layering and characterisation of active sites[J]. Catal Today,2016,268:142−149. doi: 10.1016/j.cattod.2015.12.018 [40] PENG B, FENG C, LIU S S, ZHANG R D. Synthesis of CuO catalyst derived from HKUST-1 temple for the low-temperature NH3-SCR process[J]. Catal Today,2018,314:122−128. doi: 10.1016/j.cattod.2017.10.044 [41] SI W Z, LIU H Y, YAN T, WANG H, FAN C, XIONG S C, ZHAO Z Q, PENG Y, CHEN J J, LI J H. Sn-doped rutile TiO2 for vanadyl catalysts: Improvements on activity and stability in SCR reaction[J]. Appl Catal B: Environ,2020,269:118797. doi: 10.1016/j.apcatb.2020.118797 [42] GILLOT S, TRICOT G, VEZIN H, DACQUIN J P, DUJARDIN C, GRANGER P. Development of stable and efficient CeVO4 systems for the selective reduction of NOx by ammonia: Structure-activity relationship[J]. Appl Catal B: Environ,2017,218:338−348. doi: 10.1016/j.apcatb.2017.06.049 [43] WANG C Z, TANG X L, YI H H, GAO F Y, NI S Q, ZHANG R C, SHI Y R. MnCo nanoarray in-situ grown on 3D flexible nitrogen-doped carbon foams as catalyst for high-performance denitration[J]. Colloid Surface A,2021,612:126007. doi: 10.1016/j.colsurfa.2020.126007 [44] ZHU L, ZHONG Z P, XUE J M, XU Y Y, WANG C H, WANG L X. NH3-SCR performance and the resistance to SO2 for Nb doped vanadium based catalyst at low temperatures[J]. J Environ Sci,2018,65:306−316. doi: 10.1016/j.jes.2017.06.033 [45] ZHANG Y, ZHAO L, KANG M D, CHEN Z A, GAO S J, HAO H G. Insights into high CO-SCR performance of CuCoAlO catalysts derived from LDH/MOFs composites and study of H2O/SO2 and alkali metal resistance[J]. Chem Eng J,2021,426:131873. doi: 10.1016/j.cej.2021.131873 [46] CHEN C, XIE H D, HE P W, LIU X, YANG C, WANG N, GE C M. Comparison of low-temperature catalytic activity and H2O/SO2 resistance of the Ce-Mn/TiO2 NH3-SCR catalysts prepared by the reverse co-precipitation, co-precipitation and impregnation method[J]. Appl Surf Sci,2022,571:151285. doi: 10.1016/j.apsusc.2021.151285 [47] GAO G, SHI J W, FAN Z Y, GAO C, NIU C. MnM2O4 microspheres (M = Co, Cu, Ni) for selective catalytic reduction of NO with NH3: Comparative study on catalytic activity and reaction mechanism via in-situ diffuse reflectance infrared Fourier transform spectroscopy[J]. Chem Eng J,2017,325:91−100. doi: 10.1016/j.cej.2017.05.059 [48] FANG N J, GUO J X, SHU S, LUO H D, LI J J, CHU Y H. Effect of calcination temperature on low-temperature NH3-SCR activity and the resistance of SO2 with or without H2O over Fe-Mn-Zr catalyst[J]. J Taiwan Inst Chem E,2018,93:277−288. doi: 10.1016/j.jtice.2018.07.027 [49] JIA B H, GUO J X, SHU S, FANG N J, LI J J, CHU Y H. Effects of different Zr/Ti ratios on NH3-SCR over MnO /ZryTi1–yO2: Characterization and reaction mechanism[J]. Mol Catal,2017,443:25−37. doi: 10.1016/j.mcat.2017.09.019 [50] FANG N J, GUO J X, SHU S S, LUO H D, CHU Y H, LI J J. Enhancement of low-temperature activity and sulfur resistance of Fe0.3Mn0.5Zr0.2 catalyst for NO removal by NH3-SCR[J]. Chem Eng J,2017,325:114−123. doi: 10.1016/j.cej.2017.05.053 [51] HE J, REDDY G K, THIEL S W, SMIRNIOTIS P G, PINTO N G. Ceria-modified manganese oxide/titania materials for removal of elemental and oxidized mercury from flue gas[J]. J Phys Chem C,2011,115(49):24300−24309. doi: 10.1021/jp208768p [52] ALI S, CHEN L Q, YUAN F L, LI R, ZHANG T R, BAKHTIAR S H, LENG X S, NIU X Y, ZHU Y J. Synergistic effect between copper and cerium on the performance of Cux-Ce0.5–x-Zr0.5 (x = 0.1–0.5) oxides catalysts for selective catalytic reduction of NO with ammonia[J]. Appl Catal B: Environ,2017,210:223−234. doi: 10.1016/j.apcatb.2017.03.065 [53] WANG Z Y, GUO R T, SHI X, PAN W G, LIU J, SUN X, LIU S W, LIU X Y, HAO Q. The enhanced performance of Sb-modified Cu/TiO2 catalyst for selective catalytic reduction of NOx with NH3[J]. Appl Surf Sci,2019,475:334−341. doi: 10.1016/j.apsusc.2018.12.281 [54] GUAN B, JIANG H, PENG X S, WEI Y F, LIU Z Q, CHEN T, LIN H, HUAN Z. Promotional effect and mechanism of the modification of Ce on the enhanced NH3-SCR efficiency and the low temperature hydrothermal stability over Cu/SAPO-34 catalysts[J]. Appl Catal A: Gen,2021,617:118110. doi: 10.1016/j.apcata.2021.118110 [55] CHEN J Y, FU P, LV D, LV D F, CHEN Y, FAN M L, WU J L, MESHRAM A, MU B, LI X, XIA Q B. Unusual positive effect of SO2 on Mn-Ce mixed-oxide catalyst for the SCR reaction of NOx with NH3[J]. Chem Eng J,2021,407:127071. doi: 10.1016/j.cej.2020.127071