催化学报

催化学报 ›› 2010, Vol. 31 ›› Issue (1): 106-111.

• 研究论文 • 上一篇    下一篇

改性介孔 Al2O3 负载锰基催化剂的结构及其催化氧化与抗硫性能

邹志强1, 孟明1, 于一夫1, 谢亚宁2, 胡天斗2, 张静2   

  1. 1 天津大学化工学院天津市应用催化科学与工程重点实验室, 天津 300072 2 中国科学院高能物理研究所, 北京 100049
  • 收稿日期:2010-01-25 出版日期:2010-01-25 发布日期:2010-01-25

Structure, Catalytic Oxidation Performance, and Sulfur Resistance of Mn-Based Catalysts Supported on Modified Mesoporous Al2O3

ZOU Zhiqiang1, MENG Ming1,*, YU Yifu1, XIE Yaning2, HU Tiandou2, ZHANG Jing2   

  1. 1Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China 2Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
  • Received:2010-01-25 Online:2010-01-25 Published:2010-01-25

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1108

被引次数

23

摘要： 采用分步浸渍法分别制备了 LaCeZr 和 YCeZr 组合助剂改性的介孔 Al2O3 负载的 Mn 基系列氧化物催化剂, 用 X 射线衍射、氮气吸附-脱附、X 射线吸收精细结构、X 射线光电子能谱和程序升温还原等方法对催化剂进行了表征, 探讨了催化剂中 Mn 物种的存在形式及其还原性能, 并与样品催化 CO 和 C3H8 的氧化活性相关联. 结果表明, 样品中 Mn 物种主要以 Mn3O4 形式存在, 该物种在不同样品中与载体的作用强弱不同, 从而表现出不同的还原性能和催化活性. 助剂改性有效抑制了 Mn-Al 之间的相互作用, 提高了 Mn–O 键的活动度, 从而提高了催化剂的氧化活性. 相比于 YCeZr 助剂, LaCeZr 助剂改性更大程度上提高了 Mn 物种的还原性, 因而大大提高了催化剂的氧化性能. 650 oC 焙烧的 LaCeZr 组合助剂改性的介孔 Al2O3 负载的 Mn 氧化物催化剂, 在 0.035% SO2 存在的条件下对 CO 的氧化活性并未下降, 对 C3H8 的氧化活性下降幅度也较小, 表现出优越的抗硫性能和氧化性能.

关键词: 锰氧化物, 氧化铝, 改性, 一氧化碳, 氧化, 丙烷氧化, 精细结构

Abstract: The manganese oxide catalysts supported on mesoporous Al2O3 modified by LaCeZr or YCeZr were prepared by successive impregnation. The structure of the catalysts was characterized by X-ray diffraction, N2 adsorption-desorption, X-ray absorption fine structure, X-ray photoelectron spectroscopy, and temperature-programmed reduction by H2. The state of manganese species and their reducibility were investigated and correlated with the CO and C3H8 oxidation performance of the catalysts. The results demonstrate that the manganese species mainly exist as Mn3O4 crystallites, which interact with the support Al2O3. The different interaction strength determines the reducibility and catalytic properties of the catalysts. The promoters LaCeZr or YCeZr effectively inhibit the interaction between Mn and Al oxides, increasing the mobility of Mn–O bond and the catalytic activity of the corresponding catalysts. Compared with YCeZr, the promoter LaCeZr improves the reducibility of MnOx to a larger extent, enhancing the activity more obviously. The catalysts modified by LaCeZr calcined at 650 oC exhibits high oxidation performance and sulfur resistance. In the presence of 0.035% SO2 in the feed, the CO oxidation activity of the catalyst can be well maintained, and the C3H8 oxidation activity decreases only a little.

Key words: manganese oxide, alumina, modification, carbon monoxide, oxidation, propane, oxidation, fine structure