Influence of Ho doping on the deNOx performance of Mn-Ce/TiO2 low temperature SCR catalyst
-
摘要: 采用浸渍法制备了五种掺杂不同比例的Ho的低温选择性催化还原（SCR）催化剂Mn0.4Ce0.07Hox/TiO2。研究了Ho的引入对于Mn-Ce/TiO2催化剂低温脱硝性能的影响，并采用XPS、XRF、BET、XRD、NH3-TPD等手段对催化剂的物理化学性质进行表征。结果表明，掺杂适量的Ho能够有效提高Mn-Ce/TiO2催化剂的低温脱硝性能，当Ho/Ti掺杂比例为0.1时催化剂Mn0.4Ce0.07Ho0.1/TiO2活性表现最佳，在200 ℃左右催化效率达到最高，为91.17%，在140-240 ℃催化效率达到80%以上。结果表明，Ho的掺杂能够增大催化剂的比表面积，提高催化剂化学吸附氧的浓度以及Ce的附着量。
-
关键词:
- 选择性催化还原(SCR) /
- Ho /
- 催化剂 /
- Mn-Ce/TiO2
Abstract: A series low temperature SCR catalysts Mn0.4Ce0.07Hox/TiO2 catalysts with different Ho doping ratios were prepared by impregnation method. The effects of Ho doping on the denitrification of Mn-Ce/TiO2 low temperature SCR catalyst were studied. The catalysts were characterized by using X-ray photoelectron spectroscopy (XPS), X-ray fluorescence probe (XRF), Brunauer-Emmett-Teller (BET) surface measurement, X-ray diffraction (XRD) and NH3-temperature programmed desorption (NH3-TPD). The results showed that the doping of Ho can improve the low temperature denitrification performance of Mn-Ce/TiO2 catalyst. The catalytic efficiency of Mn0.4Ce0.07Ho0.1/TiO2 with the ratio of Ho:Ti=0.1 reached 91.17% at 200℃, which is the highest during the process. The catalytic efficiency could reach more than 80% at 140-240℃. The characterization results showed that Ho doping can increase the surface area of the catalyst, increase the concentration of chemisorbed oxygen in the catalyst and increase the deposition amount of Ce on the catalyst surface.-
Key words:
- selective catalytic reduction /
- holmium /
- catalyst /
- Mn-Ce/TiO2
-
图 1 催化剂活性实验装置示意图
Figure 1 Experimental apparatus for catalyst activity test
1: N2; 2: NH3; 3: NO; 4: O2; 5: pressure reducing valve; 6: mass flow meter; 7: gas preheat mixer; 8: temperature controller; 9: tube furnace; 10: catalytic reactor
图 3 不同催化剂的XRD谱图
Figure 3 XRD patterns of Mn0.4Ce0.3Hox/TiO2 catalysts
a: Mn0.4Ce0.07Ho0.15/TiO2; b: Mn0.4Ce0.07Ho0.1/TiO2; c: Mn0.4Ce0.07Ho0.05/TiO2; d: Mn0.4Ce0.07Ho0.01/TiO2; e: Mn0.4Ce0.07/TiO2
图 5 两种催化剂的NH3-TPD谱图
Figure 5 NH3-TPD profiles of two catalysts
a: Mn0.4Ce0.07Ho0.1/TiO2; b: Mn0.4Ce0.07/TiO2
图 4 Mn0.4Ce0.07Hox/TiO2催化剂的XPS谱图
Figure 4 XPS spectra of Mn0.4Ce0.07Hox/TiO2 catalysts
a: Mn0.4Ce0.07/TiO2; b: Mn0.4Ce0.07Ho0.05/TiO2; c: Mn0.4Ce0.07Ho0.1/TiO2; d: Mn0.4Ce0.07Ho0.15/TiO2
表 1 Mn0.4Ce0.3Hox/TiO2催化剂的BET表征
Table 1 BET results of Mn0.4Ce0.3Hox/TiO2 catalysts
Sample BET surface area
A/(m2·g-1)Total pore volume
v/(cm3·g-1)Mn0.4Ce0.07/TiO2 43.03 0.2224 Mn0.4Ce0.07Ho0.01/TiO2 39.34 0.219 Mn0.4Ce0.07Ho0.05/TiO2 43.56 0.2139 Mn0.4Ce0.07Ho0.1/TiO2 44.57 0.2009 Mn0.4Ce0.07Ho0.15/TiO2 43.4 0.1997 
下载: 导出CSV
表 2 Mn0.4Ce0.3Hox/TiO2催化剂的XRF表征
Table 2 XRF results of Mn0.4Ce0.3Hox/TiO2 catalysts
Sample Metal content w/% Ti Ce Mn Ho Mn0.4Ce0.07/TiO2 65.34 4.11 30.40 0 Mn0.4Ce0.07Ho0.01/TiO2 71.12 3.29 24.96 0.63 Mn0.4Ce0.07Ho0.05/TiO2 66.74 3.62 26.21 3.44 Mn0.4Ce0.07Ho0.1/TiO2 64.14 4.28 25.87 5.72 Mn0.4Ce0.07Ho0.15/TiO2 59.17 3.84 27.62 9.39
下载: 导出CSV
-
[1] 商雪松, 陈进生, 赵金平, 张福旺, 徐亚, 徐琪. SCR脱硝催化剂失活及其原因研究[J].燃料化学学报, 2011, 39(6): 465-470. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract17761.shtmlSHANG Xue-song, CHEN Jin-sheng, ZHAO Jin-ping, ZHANG Fu-wang, XU Ya, XU Qi. Discussion on the deactivation of SCR denitrification catalyst and its reasons[J]. J Fuel Chem Technol, 2011, 39(6): 465-470. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract17761.shtml [2] BUSCA G, LIETTI L, RAMIS G, RAMIS G, BERTI F. Chemical and mechanistic aspects of the selective catalytic reduction of NOx by ammonia over oxide catalysts: A review[J]. Appl Catal B: Environ, 1998, 18(1/2): 1-36. http://www.sciencedirect.com/science/article/pii/S092633739800040X [3] LIU G, GAO P X. A review of NOx storage/reduction catalysts: Mechanism, materials and degradation studies[J]. Catal Sci Technol, 2011, 1(4): 552-568. doi: 10.1039/c1cy00007a [4] 郑足红, 童华, 童志权, 黄妍, 罗晶. Mn-V-Ce/TiO2低温催化还原NO性能研究[J].燃料化学学报, 2010, 38(3): 343-351. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract17588.shtmlZHENG Zu-hong, TONG Hua, TONG Zhi-quan, HUANG Yan, LUO Jin. Catalytic reduction of NO over Mn-V-Ce/TiO2 catalysts at low reaction temperature[J]. J Fuel Chem Technol, 2010, 38(3): 343-351. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract17588.shtml [5] JIN R B, LIU Y, WANG Y, CEN W L, WU Z B, WANG H Q, WENG X L. The role of cerium in the improved SO2 tolerance for NO reduction with NH3 over Mn-Ce/TiO2 catalyst at low temperature[J]. Appl Catal B: Environ, 2014, 148-149(4): 582-588. [6] 闫东杰, 玉亚, 徐颖, 黄学敏. Mn、Ce负载顺序对催化剂Mn-Ce/TiO2低温脱硝活性的影响[J].化工进展, 2015, 34(6): 1652-1655. http://www.hgjz.com.cn/CN/abstract/abstract17332.shtmlYAN Dong-jie, YU Ya, XU Ying, HUANG Xue-min. Effect of loading sequence of Mn and Ce on the activity of Mn-Ce/TiO2 catalysts at low-temperature[J]. Chem Ind Eng Prog, 2015, 34(6): 1652-1655. http://www.hgjz.com.cn/CN/abstract/abstract17332.shtml [7] 郑玉婴, 汪谢. Mn基低温SCR脱硝催化剂的研究进展[J].功能材料, 2014, 45(11): 11008-11012. doi: 10.3969/j.issn.1001-9731.2014.11.002ZHENG Yu-ying, WANG Xie. Research progress on Mn-based catalysts for low-temperature selective catalytic reduction of NOx[J]. J Funct Mater, 2014, 45(11): 11008-11012. doi: 10.3969/j.issn.1001-9731.2014.11.002 [8] REDDY B M, KHAN A. Structural characterization of CeO2-TiO2 and V2O5/CeO2-TiO2 catalysts by Raman And XPS techniques[J]. J Phys Chem B, 2003, 107(22): 5162-5167. doi: 10.1021/jp0344601 [9] XU G Y, WANG Y T, YANG Y, FU Y, GOU X, WU J X. Experimental research on NH3-SCR performance of Mn-Ce/TiO2 Catalyst[C]//International Conference on Machinery, Materials Engineering, Chemical Engineering and Biotechnology. 2016, 418-421. https://www.researchgate.net/publication/301641598_Experimental_Research_on_NH3-SCR_Performance_of_Mn-CeTiO2_Catalyst [10] SHENG Z Y, HU Y F, XUE J M, WANG X M, LIAO W P. A novel co-precipitation method for preparation of Mn-Ce/TiO2 composites for NOx reduction with NH3 at low temperature[J]. Environ Technol, 2012, 33(21): 2421. doi: 10.1080/09593330.2012.671370 [11] SHEN B X, LIU T, ZHAO N, YING X Y, DENG L D. Iron doped Mn-Ce/TiO2 catalyst for low temperature selective catalytic reduction of NO with NH3[J]. J Environ Sci (China), 2010, 22(9): 1447-1454. doi: 10.1016/S1001-0742(09)60274-6 [12] SIMAS A M, FREIRE R O, ROCHA G B. Lanthanide coordination compounds modeling: Sparkle/PM3 parameters for dysprosium (Ⅲ), holmium (Ⅲ) and erbium (Ⅲ)[J]. J Organomet Chem, 2008, 693(10): 1952-1956. doi: 10.1016/j.jorganchem.2008.01.029 [13] CAI H S, LIU G G, LU W Y, LI X X, YU L, LI D G. Effect of Ho-doping on photocatalytic activity of nanosized TiO2[J]. Catalyst, 2008, 26(1): 71-75. http://www.cqvip.com/QK/84120X/200801/26698841.html [14] SHI J W, ZHENG J T, HU Y, ZHAO Y C. Influence of Fe3+ and Ho3+ co-doping on the photocatalytic activity of TiO2[J]. Mater Chem Phys, 2007, 106(2/3): 247-249. http://www.sciencedirect.com/science/article/pii/S0254058407003677 [15] SHI J W, ZHENG J T, WU P. Preparation, characterization and photocatalytic activities of holmium-doped titanium dioxide nanoparticles[J]. J Hazard Mater, 2009, 161(1): 416-422. doi: 10.1016/j.jhazmat.2008.03.114 [16] ZHU Y W, ZHANG Y P, XIAO R, HUANG T J, SHEN K. Novel holmium-modified Fe-Mn/TiO2 catalysts with a broad temperature window and high sulfur dioxide tolerance for low-temperature SCR[J]. Catal Commun, 2017, 88: 64-67. doi: 10.1016/j.catcom.2016.09.031 [17] SAQER S M, , KONDARIDES D I, VERYKIOS X E. Catalytic oxidation of toluene over binary mixtures of copper, manganese and cerium oxides supported on γ-Al2O3[J]. Appl Catal B: Environ, 2011, 103(3/4): 275-286. http://www.sciencedirect.com/science/article/pii/S0926337311000099 [18] 张晓鹏, 沈伯雄. Mn/Ce-ZrO2催化剂低温NH3-SCR脱硝性能研究[J].燃料化学学报, 2013, 41(1): 123-128. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract18111.shtmlZHANG Xiao-peng, SHEN Bo-xiong. Selective catalytic reduction of NO with NH3 over Mn-based catalysts at low temperature[J]. J Fuel Chem Technol, 2013, 41(1): 123-128. http://manu60.magtech.com.cn/rlhxxb/CN/abstract/abstract18111.shtml [19] WU Z B, JIN R B, LIU Y, WANG H Q. Ceria modified MnOx/TiO2 as a superior catalyst for NO reduction with NH3 at low-temperature[J]. Catal Commun, 2008, 9(13): 2217-2220. doi: 10.1016/j.catcom.2008.05.001 [20] LIU F D, HE H, DING Y, ZHANG C B. Effect of manganese substitution on the structure and activity of iron titanate catalyst for the selective catalytic reduction of NO with NH3[J]. Appl Catal B: Environ, 2009, 93(1/2): 194-204. http://www.researchgate.net/publication/228958220_Effect_of_manganese_substitution_on_the_structure_and_activity_of_iron_titanate_catalyst_for_the_selective_catalytic_reduction_of_NO_with_NH3 [21] 金瑞奔. 负载型Mn-Ce系列低温SCR脱硝催化剂制备、反应机理及抗硫性能研究[D]. 浙江: 浙江大学, 2010. http://d.wanfangdata.com.cn/Thesis/Y1713847JIN Rui-beng. Low temperature SCR study on preparation, reaction mechanism and anti-sulfur performance of supported Mn-Ce series catalyst[D]. Zhejiang: Zhejiang University, 2010. http://d.wanfangdata.com.cn/Thesis/Y1713847 [22] BONINGARI, T, ETTIREDDY P R, SOMOGYVARI A, LIU Y, VORONTSOV A, MCDONALD C A, SMIRNIOTIS P G. Influence of elevated surface texture hydrated titania on Ce-doped Mn/TiO2 catalysts for the low-temperature SCR of NOx under oxygen-rich conditions[J]. J Catal, 2015, 325: 145-155. doi: 10.1016/j.jcat.2015.03.002 [23] 廖永进, 张亚平, 余岳溪, 李娟, 郭婉秋, 汪小蕾. MnOx/WO3/TiO2低温选择性催化还原NOx机理的原位红外研究[J].化工学报, 2016, 67(12): 5031-5039. http://www.cqvip.com/QK/90316X/201612/670745059.htmlLIAO Yong-jin, ZHANG Ya-ping, YU Yue-xi, LI Juan, GUO Wang-qiu, WANG Xiao-lei. In situ FT-IR studies on low temperature NH3-SCR mechanism of NOx over MnOx/WO3/TiO2 catalyst[J]. CIESC J, 2016, 67(12): 5031-5039. http://www.cqvip.com/QK/90316X/201612/670745059.html -
点击查看大图
图(5) / 表(2)
计量
- 文章访问数: 71
- HTML全文浏览量: 26
- PDF下载量: 7
- 被引次数: 0
