Effect of WO3 content on the catalytic activity of CeO2-ZrO2-WO3 for selective catalytic reduction of NO with NH3
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摘要: 采用水热法制备了CeO2-ZrO2-WO3(CZW)催化剂,考察了WO3含量对CZW催化剂上NH3选择性催化还原NOx性能的影响,并利用X射线衍射、N2吸附-脱附、H2程序升温还原、NH3和NO程序升温脱附等方法对其进行了表征。结果表明,WO3以无定形的形式存在于催化剂中,添加WO3后显著提高了催化剂的表面酸性,并且在CZW催化剂上出现了强吸附的NO物种,从而有利于提高催化剂的活性。另外,适量的WO3引入将增大催化剂的比表面积,促进催化剂的氧化还原性能,这将有利于提高SCR的催化活性。和CeO2-ZrO2催化剂相比,当WO3的含量为20%时,CZW催化剂表现出良好的抗硫性能。此外,当空速为60 000 h-1时,在200~463 ℃,该催化剂显示出了大于90% NOx转化率。Abstract: A series of CeO2-ZrO2-WO3 catalysts (CZW) was prepared by the hydrothermal method. The effect of WO3 content on their catalytic properties for selective reduction of NO<em>x with NH3 was investigated. The catalysts were characterized by X-ray diffraction, N2 sorption, H2 temperature-programmed reduction, NH3 temperature-programmed desorption and NO temperature-programmed desorption techniques. It was shown that WO3 existed as amorphous species in the CZW. Introduction of WO3 in the CZW dramatically enhanced its surface acidity and gave rise to strongly adsorbed NO species, consequently increasing the catalytic activity. In addition, appropriate amounts of WO3 also increased the surface area and improved the reduction behavior of the catalyst. Compared to the CeO2-ZrO2, the CZW with 20% WO3 not only exhibited high resistivity to SO2, but also had a wider reaction temperature window. It showed a NOx conversion of> 90% at the space velocity of 60 000 h-1 in the temperature range of 200~463 ℃.
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Key words:
- selective catalytic reduction /
- WO3 /
- redox property /
- acidity
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LI X L, LI Y H, DENG S S, RONG T A. A Ce-Sn-Ox catalyst for the selective catalytic reduction of NOx with NH3[J]. Catal Commun, 2013, 40: 47-50. 王燕彩, 刘昕, 宁平, 张秋林, 张金辉, 徐利斯, 唐小苏, 王明智. 制备方法对氧化锰八面体分子筛的NH3选择性催化还原NOx性能的影响[J]. 燃料化学学报, 2014, 42(11): 1357-1364. (WANG Yan-cai, LIU Xin, NING Ping, ZHANG Qiu-lin, ZHANG Jin-hui, XU Li-si, TANG Xiao-su, WANG Ming-zhi. Effect of preparation methods on selective catalytic reduction of NOx with NH3 over manganese oxide octahedral molecular sieves[J]. J Fuel Chem Technol, 2014, 42(11): 1357-1364.) 孔志坚, 王成, 丁正南, 陈银飞, 张泽凯. Li改性MnO2及LiMn2O4催化NH3-SCR反应性能研究[J]. 燃料化学学报, 2014, 42(12): 1447-1454. (KONG Zhi-jian, WANG Cheng, DING Zheng-nan, CHEN Yin-fei, ZHANG Ze-kai. Li-modified MnO2 catalyst and LiMn2O4 for selective catalytic reduction of NO with NH3[J]. J Fuel Chem Technol, 2014, 42(12): 1447-1454.) 沈伯雄, 马娟. SiO2改性的V2O5-WO3/TiO2催化剂抗碱中毒性能研究[J]. 燃料化学学报, 2012, 40(2): 247-251. (SHEN Bo-xiong, MA Juan. Alkali-resistant performance of V2O5-WO3/TiO2 catalyst modified by SiO2[J]. J Fuel Chem Technol, 2012, 40(2): 247-251.) SHEN Y S, ZHU S M, QIU T, SHEN S B. A novel catalyst of CeO2/Al2O3 for selective catalytic reduction of NO by NH3[J]. Catal Commun, 2009, 11(1): 20-23. CHEN L, LI J H, GE M F. DRIFT study on cerium-tungsten/titiania catalyst for selective catalytic reduction of NOx with NH3[J]. Environ Sci Technol, 2010, 44(24): 9590-9596. 沈伯雄, 姚燕, 马宏卿, 刘亭. 铈改性钛基层柱粘土负载锰催化剂上低温NH3选择性催化还原NO[J]. 催化学报, 2011, 32(12): 1803-1811. (SHEN Bo-xiong, YAO Yan, MA Hong-qing, LIU Ting. Ceria modified MnOx/TiO2-pillared clays catalysts for the selective catalytic reduction of NO with NH3 at low temperature[J]. Chin J Catal, 2011, 32(12): 1803-1811.) SHAN W P, LIU F D, HE H, SHI X Y, ZHANG C B. An environmentally-benign CeO2-TiO2 catalyst for the selective catalytic reduction of NOx with NH3 in simulated diesel exhaust[J]. Catal Today, 2012, 184(1): 160-165. PENG Y, LIU Z M, NIU X W, ZHOU L, FU C W, ZHANG H, LI J H, HA W. Manganese doped CeO2-WO3 catalysts for the selective catalytic reduction of NOx with NH3: An experimental and theoretical study[J]. Catal Commun, 2012, 19: 127-131. ZHOU R X, ZHAO B, YUE B H. Effects of CeO2-ZrO2 present in Pd/Al2O3 catalysts on the redox behavior of PdOx and their combustion activity[J]. Appl Surf Sci, 2008, 254(15): 4701-4707. 李烨, 程昊, 李德意, 秦永生, 王树东. 耐高温WO3-CeO2-ZrO2催化剂的合成及其在柴油车尾气氨-选择性催化还原一氧化氮中的应用[J]. 燃料化学学报, 2008, 36(6): 762-766. (LI Ye, CHENG Hao, LI De-yi, QIN Yong-sheng, WANG Shu-dong. Synthesis of heat-resistant WO3-CeO2-ZrO2 catalyst and its performance for NH3-SCR of NO in diesel exhaust[J]. J Fuel Chem Technol, 2008, 36(6): 762-766.) XU H D, WANG Y, CAO Y, FANG Z T, LIN T, GONG M C, CHEN Y Q. Catalytic performance of acidic zirconium-based composite oxides monolithic catalyst on selective catalytic reduction of NOx with NH3[J]. Chem Eng J, 2014, 240: 62-73. 吴大旺, 张秋林, 林涛, 龚茂初, 陈耀强. CexTi1-xO2负载锰基催化剂的制备及其低温NH3选择催化还原NO[J]. 无机化学学报, 2011, 27(1): 53-60. (WU Da-wang, ZHANG Qiu-lin, LIN Tao, GONG Mao-chu, CHEN Yao-qiang. CexTi1-xO2 supported manganese-based catalyst: Preparation and catalytic performance for selective catalytic reduction of NO with NH3 at low temperature[J]. Chin J Inorg Chem, 2011, 27(1): 53-60.) LIU Z M, ZHANG S X, LI J H, MA L L. Promoting effect of MoO3 on the NOx reduction by NH3 over CeO2/TiO2 catalyst studied with in situ DRIFTS[J]. Appl Catal B: Environ, 2014, 144: 90-95. QU R Y, GAO X, CEN K F, LI J H. Relationship between structure and performance of a novel cerium-niobium binary oxide catalyst for selective catalytic reduction of NO with NH3[J]. Appl Catal B: Environ, 2013, 142-143: 290-297. 郭家秀, 袁书华, 龚茂初, 张磊, 吴冬冬, 赵明, 陈耀强. Ce0.35Zr0.55La0.10O1.95对低贵金属Pt-Rh型三效催化剂性能的影响[J]. 物理化学学报, 2007, 23(1): 73-78. (GUO Jia-xiu, YUAN Shu-hua, GONG Mao-chu, ZHANG Lei, WU Dong-dong, ZHAO Ming, CHEN Yao-qiang. Influence of Ce0.35Zr0.55La0.10O1.95 solid solution on the performance of Pt-Rh three-way catalysts[J]. Acta Phys Chim Sin, 2007, 23(1): 73-78.) 林涛, 李伟, 龚茂初, 喻瑶, 杜波, 陈耀强. ZrO2-TiO2-CeO2的制备及其在NH3选择性催化还原NO的应用[J]. 物理化学学报, 2007, 23(12): 1851-1856. (LIN Tao, LI Wei, GONG Mao-chu, YU Yao, DU Bo, CHEN Yao-qiang. Prepareration of ZrO2-TiO2-CeO2 and its application in the selective catalytic reduction of NO with NH3[J]. Acta Phys Chim Sin, 2007, 23(12): 1851-1856.) PENG Y, LI J H, CHEN L, CHEN J H, HAN J, ZHANG H, HAN W. Alkali metal poisoning of a CeO2-WO3 catalyst used in the selective catalytic reduction of NOx with NH3: An experimental and theoretical study[J]. Environ Sci Technol, 2012, 46: 2864-2869. XU L, LI X S, CROCKER M, ZHANG Z S, ZHU A M, SHI C. A study of the mechanism of low-temperature SCR of NO with NH3 on MnOx/CeO2[J]. J Mol Catal A: Chem, 2013, 378: 82-90. JIN R B, LIU Y, WU Z B, WANG H Q, GU T T. Low-temperature selective catalytic reduction of NO with NH3 over Mn-Ce oxides supported on TiO2 and Al2O3: A comparative study[J]. Chemosphere, 2010, 78(9): 1160-1166. LIU F D, ASAKURA K, HE H, SHAN W P, SHI X Y, ZHANG C B. Influence of sulfation on iron titanate catalyst for the selective catalytic reduction of NOx with NH3[J]. Appl Catal B: Environ, 2011, 103(3/4): 369-377. 刘越, 江博琼, 吴忠标. 以MnOx/TiO2作为催化剂的低温SCR反应过程中还原剂NH3的作用[J]. 环境科学学报, 2008, 28(4): 671-675. (LIU Yue, JIANG Bo-qiong, WU Zhong-biao. The role of NH3 in the low-temperature selective catalytic reduction of NO over MnOx/TiO2[J]. Acta Sci Circum, 2008, 28(4): 671-675.) LIETTI L, ALEMANY J L, FORZATTI P, BUSCA G, RAMIS G, GIAMELLO E, BREGANI F. Reactivity of V2O5-WO3/TiO2 catalysts in the selective catalytic reduction of nitric oxide by ammonia[J]. Catal Today, 1996, 29(1/4): 143-148. XIE G Y, LIU Z Y, ZHU Z P, LIU Q Y, GE J, HUANG Z G. Simultaneous removal of SO2 and NOx from flue gas using a CuO/Al2O3 catalyst sorbent I. Deactivation of SCR activity by SO2 at low temperatures[J]. J Catal, 2004, 224(1): 36-41. 李伟, 林涛, 张秋林, 龚茂初, 陈耀强. 整体式MnOx-CeO2/ZrO2-TiO2催化剂用于NH3低温选择性催化还原NO[J]. 催化学报, 2009, 30(2): 104-110. (LI Wei, LIN Tao, ZHANG Qiu-lin, GONG Mao-chu, CHEN Yao-qiang. Low temperature selective catalytic reduction of NO with NH3 over MnOx-CeO2/ZrO2-TiO2 monolith catalyst[J]. Chin J Catal, 2009, 30(2): 104-110.) 罗红成, 黄碧纯, 付名利, 吴军良, 叶代启. MnOx/MWCNTs低温氨选择性催化还原NOx硫中毒机理[J]. 物理化学学报, 2012, 28(9): 2175-2182. (LUO Hong-cheng, HUANG Bi-chun, FU Ming-li, WU Jun-liang, YE Dai-qi. SO2 deactivation mechanism of MnOx/MWCNTs catalyst for low-temperature selective catalytic reduction of NOx by ammonia[J]. Acta Phys Chim Sin, 2012, 28(9): 2175-2182.) 沈伯雄, 刘亭. 低温NH3-SCR 催化剂MnOx-CeOx/ACF的SO中毒机理[J]. 物理化学学报, 2010, 26(11): 3009-3016. (SHEN Bo-xiong, LIU Ting. Deactivation of MnOx-CeOx/ACF catalysts for low-temperature NH3-SCR in the presence of SO2[J]. Acta Phys Chim Sin, 2010, 26(11): 3009-3016.)
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