Catalytic decomposition of N2O over Mg-Fe mixed oxides
-
摘要: 用共沉淀法制备了一组Mg-Fe复合氧化物催化剂,用于N2O催化分解,考察了催化剂组成、焙烧温度、负载助剂钾等参数对其催化活性的影响。采用N2物理吸附、X射线衍射、H2-程序升温还原等技术对催化剂进行了结构表征。结果表明,500 ℃焙烧的Mg0.6Fe0.4Fe2O4催化剂对于N2O分解反应有较高活性,而K改性的催化剂活性均有所降低,且K的负载量越高,改性催化剂的活性越低,这是由于负载的K粒子抑制了表面铁物种的还原,降低了催化剂的比表面积。在有氧无水、水氧共存条件下连续反应10 h,Mg0.6Fe0.4Fe2O4的催化活性和稳定性均显著高于FeOx催化剂。
-
关键词:
- N2O催化分解 /
- Mg-Fe复合氧化物 /
- K改性 /
- MgxFe1-xFe2O4 /
- 催化活性
Abstract: A series of MgxFe1-xFe2O4 spinel oxides were prepared and characterized by means of nitrogen physisorption, X-ray diffraction (XRD) and temperature-programmed reduction of hydrogen (H2-TPR). The effect of composition, calcination temperature, and potassium doping on the catalytic activity of the Mg-Fe mixed oxides in N2O decomposition was investigated. The results indicated that the Mg0.6Fe0.4Fe2O4 catalyst calcined at 500 ℃ exhibits highest activity in N2O decomposition. Unexpectedly, the catalyst activity is depressed by the addition of potassium, as the potassium doping may inhibit the reduction of surface iron oxides and reduce the surface area of K-modified catalysts. Long-term tests at 500 ℃ for 10 h also illustrate that Mg0.6Fe0.4Fe2O4 is superior to FeOx catalyst either in the oxygen-alone or in the oxygen-steam concomitant atmosphere.-
Key words:
- N2O decomposition /
- Mg-Fe mixed oxides /
- K doping /
- MgxFe1-xFe2O4 /
- catalytic activity
-
KOVANDA F, ROJKA T, BEZDICKA P, JIRATOVA K, OBALOVA L, PACULTOVA K, BASTL Z, GRYGAR T. Effect of hydrothermal treatment on properties of Ni-Al layered double hydroxides and related mixed oxides[J]. J Solid State Chem, 2009, 182(1): 27-36. 武海鹏, 钱振英, 徐晓玲, 徐秀峰. K改性NiAl类水滑石衍生复合氧化物催化分解N2O[J]. 燃料化学学报, 2011, 39(2): 115-121. (WU Hai-peng, QIAN Zhen-ying, XU Xiao-ling, XU Xiu-feng. N2O decomposition over K-promoted NiAl mixed oxides derived from hydrotalcite-like compounds[J]. Journal of Fuel Chemistry and Technology, 2011, 39(2): 115-121.) 潘燕飞, 冯鸣, 崔仙, 徐秀峰. 有氧气氛中碱金属改性CuAl复合氧化物催化分解N2O的活性[J]. 燃料化学学报, 2012, 40(5): 601-607. (PAN Yan-fei, FENG Ming, CUI Xian, XU Xiu-feng. Catalytic activity of alkali metal doped Cu-Al mixed oxides for N2O decomposition in the presence of oxygen[J]. Journal of Fuel Chemistry and Technology, 2012, 40(5): 601-607.) YAN L, REN T, WANG X L, JI D, SUO J S. Catalytic decomposition of N2O over MxCo1-xCo2O4 (M=Ni, Mg) spinel oxides[J]. Appl Catal B: Environ, 2003, 45(2): 85-90. YAN L, REN T, WANG X L, GAO Q, JI D, SUO J S. Excellent catalytic performance of ZnxCo1-xCo2O4 spinel catalysts for the decomposition of nitrous oxide[J]. Catal Commun, 2003, 4(10): 505-509. 窦喆, 张海杰, 潘燕飞, 徐秀峰. N2O在钾改性Cu-Co尖晶石型复合氧化物上的催化分解[J]. 燃料化学学报, 2014, 42(2): 238-245. (DOU Zhe, ZHANG Hai-jie, PAN Yan-fei, XU Xiu-feng. Catalytic decomposition of N2O over potassium-modified Cu-Co spinel oxides[J]. Journal of Fuel Chemistry and Technology, 2014, 42(2): 238-245.) AMROUSSE R, KATSUMI T. Substituted ferrite MxFe1-xFe2O4 (M=Mn, Zn) catalysts for N2O catalytic decomposition processes[J]. Catal Commun, 2012, 26: 194-198. AMROUSSE R, TSUTSUMI A, BACHAR A, LAHCENE D. N2O catalytic decomposition over nano-sized particles of Co-substituted Fe3O4 substrates[J]. Appl Catal A: Gen, 2013, 450: 253-260. CHENG H K, HUANG Y Q, WANG A Q, LI L, WANG X D, ZHANG T. N2O decomposition over K-promoted Co-Al catalysts prepared from hydrotalcite-like precursors[J]. Appl Catal B: Environ, 2009, 89(3/4): 391-397. STELMACHOWSKI P, MANIAK G, KOTARBA A, SOJKA Z. Strong electronic promotion of Co3O4 towards N2O decomposition by surface alkali dopants[J]. Catal Commun, 2009, 10(7): 1062-1065. PASHA N, LINGAIAH N, REDDY P S S, PRASAD P S S. Direct decomposition of N2O over cesium-doped CuO catalysts[J]. Catal Lett, 2009, 127(1/2): 101-106. OBALOVÁ L, KARÁSKOVÁ K, JIRÁTOVÁ K, KOVANDA F. Effect of potassium in calcined Co-Mn-Al layered double hydroxide on the catalytic decomposition of N2O[J]. Appl Catal B: Environ, 2009, 90(1/2): 132-140. OBALOVÁ L, MANIAK G, KARÁSKOVÁ K, KOVANDA F, KOTARBA A. Electronic nature of potassium promotion effect in Co-Mn-Al mixed oxide on the catalytic decomposition of N2O[J]. Catal Commun, 2011, 12(12): 1055-1058. 冯鸣, 窦喆, 徐秀峰. Zn-Fe尖晶石型复合氧化物催化分解N2O[J]. 燃料化学学报, 2013, 41(6): 729-734. (FENG Ming, DOU Zhe, XU Xiu-feng. Catalytic decomposition of N2O over Zn-Fe spinel oxides[J]. Journal of Fuel Chemistry and Technology, 2013, 41(6): 729-734.)
点击查看大图
计量
- 文章访问数: 416
- HTML全文浏览量: 14
- PDF下载量: 415
- 被引次数: 0