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摘要: 鐵礦石燒結煙氣中含有較高濃度的CO（體積分數0.5%～2%），因此對其進行CO脫除意義重大。為了探究不同類型催化劑的催化效果，采用浸漬法制備了Pt涂層蜂窩金屬催化劑和鐵鈰氧化物催化劑，并通過X射線熒光光譜分析（XRF）對其組分含量進行了分析。二者在模擬燒結煙氣中進行CO脫除性能的對比實驗，活性測試表明，不同CO初始體積分數、煙氣溫度以及水汽含量對CO催化氧化的脫除效率影響較大。當模擬煙氣中不含水汽的時候，二者在180 ℃及更高溫度下對CO的脫除效率均能達到60%以上。反應溫度為180 ℃，水汽體積分數為11.7%時，Pt負載型催化劑中的CO轉化率為63.9%，而該條件下Ce改性Fe2O3催化劑的CO轉化率僅為34.9%。當溫度在180～300 ℃范圍內，Pt負載型催化劑具有較好的抗水性，且繼續升高溫度，水汽體積分數增加對催化劑效率的負面影響更顯著。如水汽體積分數從0增加到27.1%時，與180 ℃時的催化效率相比，Pt負載型催化劑在240 ℃時的催化效率由73.9%降至62.3%，降幅遠遠增大。另外，對這兩種催化劑進行了抗硫性測試。當水汽體積分數為0時，Ce改性Fe2O3催化劑抗硫性更佳，但當SO2和水汽同時存在的情況下，Pt負載型催化劑具有更好的抗硫性。因此，在實際燒結中建議采取高效的脫硫措施并布置脫水層以減少其對于催化劑的負面影響。Abstract: The iron ore sintering flue gas contains a relatively high CO concentration (volume fraction of 0.5%?2%); therefore, it is of great significance to remove CO. To study the catalytic effect of different catalysts, typical Pt-supported catalyst and Ce-doped Fe2O3 catalyst were prepared by impregnation, and their components were analyzed by X-ray fluorescence. The activity results show that different initial CO concentrations, flue gas temperature, and water vapor volume fraction have a great influence on the removal efficiency of CO catalytic oxidation. When there is no water vapor in the flue gas, the CO removal efficiency of the two catalysts is over 60%. When the reaction temperature is 180 ℃ and the water vapor volume fraction is 11.7%, the CO conversion efficiency of the Pt-supported catalyst is 63.9%, but the CO conversion efficiency of the Ce-doped Fe2O3 catalyst is only about 34.9%. Furthermore, the results show that the Pt-supported catalyst has a better water resistance in the range of 180?300 ℃. If the reaction temperature is higher, the increase in water vapor volume will have a more negative impact on the catalytic efficiency of both catalysts. For example, when the volume fraction of water vapor increases from 0 to 27.1%, the catalytic efficiency of the Pt-supported catalyst drops from 73.9% to 62.3%, which decreases much more compared to the case of 180 ℃. In addition, the sulfur resistance of the two catalysts was also tested. The Ce-doped Fe2O3 catalyst is more resistant to SO2, when there is no water vapor. However, when SO2 and water vapor exist at the same time, the Pt-supported catalyst has better sulfur resistance. Therefore, during the actual sintering process, it is recommended to adopt efficient desulfurization measures and arrange the water absorption layer in order to reduce the negative impacts on catalysts.
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Key words:
- catalyst /
- oxidation /
- reduction /
- carbon monoxide /
- iron ore sinter /
- humidity
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圖 1 模擬燒結尾氣CO脫除實驗裝置圖
Figure 1. Schematic diagram of the experimental rig for CO removal
圖 2 不同初始CO體積分數下催化劑的脫除結果。（a） Pt蜂窩金屬催化劑；（b） Ce改性的Fe2O3；（c） 兩者脫除效率
Figure 2. Removal results of the catalyst at different initial CO concentrations: (a) Pt catalyst; (b) Ce?modified Fe2O3; (c) removal efficiency
圖 3 催化劑在不同溫度下的脫除結果。（a） Pt蜂窩金屬催化劑；（b） Ce改性的Fe2O3；（c） 兩者脫除效率
Figure 3. Removal results of the catalyst at different temperatures: (a) Pt catalyst; (b) Ce?modified Fe2O3; (c) removal efficiency
圖 4 Pt蜂窩金屬催化劑在不同水汽體積分數下的CO脫除性能。（a） 180 ℃；（b） 240 ℃
Figure 4. Removal results of Pt catalyst under different water vapor volume fractions: (a) 180 ℃; (b) 240 ℃
圖 5 Ce改性的Fe2O3催化劑在不同水汽體積分數下的CO脫除性能。（a） 180 ℃；（b） 240 ℃
Figure 5. Removal results of Fe2O3?CeO2 catalyst under different water vapor volume fractions: (a) 180 ℃; (b) 240 ℃
圖 6 不同水汽體積分數下兩種催化劑不同溫度的脫除效率
Figure 6. Removal efficiency of two catalysts under different water vapor volume fractions
圖 7 兩種催化劑抗硫性測試（CO初始體積分數4.7 × 10?3，溫度為180 ℃）
Figure 7. Sulfur resistance tests of two catalysts（the initial volume fraction of CO is 4.7×10?3, temperature is 180 ℃）
表 1 催化劑性能測試試驗工況表
Table 1. Test conditions of catalysts
工況 反應溫度/℃ 水汽體積分數/% 近似初始CO體積分數/10?3 1 180 0 2 2 180 0 3 3 180 0 5 4 180 0 7.5 5 120 0 4.5 6 180 0 4.5 7 240 0 4.5 8 300 0 4.5 9 180 11.7 4.5 10 180 19.9 4.5 11 180 27.1 4.5 12 240 11.7 4.5 13 240 19.9 4.5 14 240 27.1 4.5 
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表 2 兩種催化劑的比表面積測試結果
Table 2. BET test results of two catalysts
樣品 比表面積/（m2·g?1） Pt/Al2O3涂層蜂窩金屬型催化劑 50.9 Ce改性Fe2O3?Al2O3催化劑 44.7
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表 3 Pt/Al2O3涂層蜂窩金屬型催化劑XRF分析結果（質量分數）
Table 3. XRF test results of Pt/Al2O3 catalyst
% Al Fe Cr Ni Pt Si Gd Mn Mg Ca 36.99 36.69 12.98 2.07 0.448 0.26 0.24 0.15 0.0684 0.0592
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表 4 Ce改性Fe2O3催化劑XRF分析結果（質量分數）
Table 4. XRF test results of Ce-doped Fe2O3 catalyst
% Al2O3 Fe2O3 CeO2 NiO F SiO2 PtO2 Gd2O3 MnO MgO 48.96 29.21 7.28 1.39 0.5 0.369 0.272 0.117 0.112 0.0805
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參考文獻
[1] Wu S L, Chen D F, Zhao C X, et al. Exhaust emission law at different bed depth sintering process. J Univ Sci Technol Beijing, 2010, 32(2): 164吳勝利, 陳東峰, 趙成顯, 等. 不同料層高度燒結過程尾氣排放規律. 北京科技大學學報, 2010, 32(2):164 [2] Feng X, Zhang Z X, Yang B, et al. Experimental study of the ventilation volume’s influence on the composition of sintering flue gas. China Metall, 2015, 25(4): 28馮祥, 張忠孝, 楊斌, 等. 風量對燒結煙氣成分影響的實驗研究. 中國冶金, 2015, 25(4):28 [3] Fan X H, Yu Z Y, Gan M, et al. Appropriate technology parameters of iron ore sintering process with flue gas recirculation. ISIJ Int, 2014, 54(11): 2541 doi: 10.2355/isijinternational.54.2541 [4] Liang F X, Zhu H Q, Qin Z F, et al. Low-temperature catalytic oxidation of carbon monoxide. Prog Chem, 2008, 20(10): 1453梁飛雪, 朱華青, 秦張峰, 等. 一氧化碳低溫催化氧化. 化學進展, 2008, 20(10):1453 [5] Hu L, Zhang H D, Wang X H, et al. Active components of the catalysts for catalytic oxidation of CO. Mater Rev, 2016, 30(11): 46胡玲, 張海東, 王小菡, 等. CO催化氧化催化劑活性成分研究進展. 材料導報, 2016, 30(11):46 [6] Satsuma A, Osaki K, Yanagihara M, et al. Activity controlling factors for low-temperature oxidation of CO over supported Pd catalysts. Appl Catal B, 2013, 132-133: 511 doi: 10.1016/j.apcatb.2012.12.025 [7] Choi J, Shin C B, Suh D J. Co-promoted Pt catalysts supported on silica aerogel for preferential oxidation of CO. Catal Commun, 2008, 9(5): 880 doi: 10.1016/j.catcom.2007.09.036 [8] Li S Y, Liu G, Lian H L, et al. Low-temperature co oxidation over supported Pt catalysts prepared by colloid-deposition method. Catal Commun, 2008, 9(6): 1045 doi: 10.1016/j.catcom.2007.10.016 [9] Pozdnyakova O, Teschner D, Wootsch A, et al. Preferential CO oxidation in hydrogen (PROX) on ceria-supported catalysts, part I: oxidation state and surface species on Pt/CeO2 under reaction conditions. J Catal, 2006, 237(1): 1 doi: 10.1016/j.jcat.2005.10.014 [10] Zhu H G, Liang C D, Yan W F, et al. Preparation of highly active silica-supported Au catalysts for CO oxidation by a solution-based technique. J Phys Chem B, 2006, 110(22): 10842 doi: 10.1021/jp060637q [11] Qian K, Huang W X, Jiang Z Q, et al. Anchoring highly active gold nanoparticles on SiO2 by CoOx additive. J Catal, 2007, 248(1): 137 doi: 10.1016/j.jcat.2007.02.010 [12] Zhang X D, Qu Z P, Yu F L, et al. Progress in carbon monoxide oxidation over nano-sized Ag catalysts. Chin J Catal, 2013, 34(7): 1277張曉東, 曲振平, 于芳麗, 等. 納米銀催化劑上CO氧化反應研究進展. 催化學報, 2013, 34(7):1277 [13] Zhang X D, Qu Z P, Li X Y, et al. Low temperature CO oxidation over Ag/SBA-15 nanocomposites prepared via in-situ “pH-adjusting” method. Catal Commun, 2011, 16(1): 11 doi: 10.1016/j.catcom.2011.08.030 [14] Li L C, Wang C S, Ma X X, et al. An Au?Cu bimetal catalyst supported on mesoporous TiO2 with stable catalytic performance in CO oxidation. Chin J Catal, 2012, 33(11): 1778李力成, 王昌松, 馬璇璇, 等. 一種具有CO催化氧化穩定性的金銅雙金屬/介孔氧化鈦催化劑. 催化學報, 2012, 33(11):1778 [15] Luo M F, Fang P, He M, et al. In situ XRD, Raman, and TPR studies of CuO/Al2O3 catalysts for CO oxidation. J Mol Catal A Chem, 2005, 239(1-2): 243 doi: 10.1016/j.molcata.2005.06.029 [16] Kondrat S A, Davies T E, Zu Z L, et al. The effect of heat treatment on phase formation of copper manganese oxide: influence on catalytic activity for ambient temperature carbon monoxide oxidation. J Catal, 2011, 281(2): 279 doi: 10.1016/j.jcat.2011.05.012 [17] Ramesh K, Chen L W, Chen F X, et al. Re-investigating the CO oxidation mechanism over unsupported MnO, Mn2O3 and MnO2 catalysts. Catal Today, 2008, 131(1-4): 477 doi: 10.1016/j.cattod.2007.10.061 [18] Frey K, Iablokov V, Sáfrán G, et al. Nanostructured MnOx as highly active catalyst for CO oxidation. J Catal, 2012, 287: 30 doi: 10.1016/j.jcat.2011.11.014 [19] Lou Y, Wang L, Zhao Z Y, et al. Low-temperature CO oxidation over Co3O4-based catalysts: significant promoting effect of Bi2O3, on Co3O4 catalyst. Appl Catal B, 2014, 146: 43 doi: 10.1016/j.apcatb.2013.06.007 [20] Jiang D E, Dai S. The role of low-coordinate oxygen on Co3O4(110) in catalytic CO oxidation. Phys Chem Chem Phys, 2011, 13: 978 doi: 10.1039/C0CP01138J [21] Liu X J, Liu J F, Chang Z, et al. Crystal plane effect of Fe2O3 with various morphologies on CO catalytic oxidation. Catal Commun, 2011, 12(6): 530 doi: 10.1016/j.catcom.2010.11.016 [22] Wagloehner S, Reichert D, Leon-Sorzano D, et al. Kinetic modeling of the oxidation of CO on Fe2O3 catalyst in excess of O2. J Catal, 2008, 260(2): 305 doi: 10.1016/j.jcat.2008.09.018 [23] Jia A P, Jiang S Y, Lu J Q, et al. Study of catalytic activity at the CuO?CeO2 interface for CO oxidation. J Phys Chem C, 2010, 114(49): 21605 doi: 10.1021/jp108556u [24] Sedmak G, Ho?evar S, Levec J. Kinetics of selective CO oxidation in excess of H2 over the nanostructured Cu0.1Ce0.9O2?y catalyst. J Catal, 2003, 213(2): 135 doi: 10.1016/S0021-9517(02)00019-2 [25] Zhang Q L, Xu L S, Liu X, et al. Effect of P123 on structure and CO catalytic oxidation performance of CuO?CeO2 catalysts. Chin J Inorg Chem, 2015, 31(8): 1555張秋林, 徐利斯, 劉昕, 等. P123軟模板對CuO?CeO2結構及其CO催化氧化性能的影響. 無機化學學報, 2015, 31(8):1555 [26] Tang C W, Kuo C C, Kuo M C, et al. Influence of pretreatment conditions on low-temperature carbon monoxide oxidation over CeO2/Co3O4 catalysts. Appl Catal A, 2006, 309(1): 37 doi: 10.1016/j.apcata.2006.04.020 [27] Chen R, Gao X Y, Wang J, et al. Effect of Ce addition on Fe2O3 catalyst towards CO catalytic oxidation. Chem Ind Eng Prog, 2017, 36(10): 210陳然, 高曉亞, 王晶, 等. Ce改性Fe2O3催化劑對CO催化氧化的影響. 化工進展, 2017, 36(10):210 [28] Nie C. Preparation and Study of Metallic Monolithic Catalysts for Preferential CO Oxidation in Excess Hydrogen [Dissertation]. Tianjin: Tianjin University, 2008聶春. 富氫氣體中金屬整體式催化劑制備及CO選擇性氧化性能研究[學位論文]. 天津: 天津大學, 2008 [29] Gu B, He S F, Jiang C Y. Application of spray drying absorption (SDA) In desulphurization of sintering flue gas. Environ Eng, 2013, 31(2): 53顧兵, 何申富, 姜創業. SDA脫硫工藝在燒結煙氣脫硫中的應用. 環境工程, 2013, 31(2):53 -
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