铈改性CuMn/Al2O3/堇青石整体催化剂的甲苯催化燃烧性能研究

Catalytic combustion of toluene over cerium modified CuMn/Al2O3/cordierite monolithic catalyst

  • 摘要: 本研究以堇青石为载体,采用超声浸渍法制备了一系列CuMnCex/Al2O3/堇青石整体式催化剂,同时,通过N2吸附-脱附、XRD、SEM、EDX、H2-TPR、O2-TPD、XPS和EPR等方法对样品的物理、化学性质进行了系统的表征分析。实验结果表明,CuMnCex/Al2O3/堇青石整体式催化剂中的Ce含量明显影响甲苯催化燃烧性能。其中,CuMnCe2/Al2O3/堇青石整体式催化剂对甲苯氧化具有最高活性,当甲苯浓度为1 g/L、空速为78000 mL/(g·h)、温度为263 °C时甲苯转化率达到90%,究其原因为CeO2在CuMnOx上分散均匀,不仅提高了氧空位的浓度和氧物种的迁移率,还增强了催化剂的低温还原性。同时,CuMnCe2/Al2O3/堇青石整体式催化剂在长期评价和循环测试中呈现良好的稳定性。

     

    Abstract: Catalytic combustion is an effective approach to remove volatile organic compounds, in which the development of highly active and durable catalyst is extremely crucial. Herein, a series of CuMnCex/Al2O3/cordierite monolithic catalysts were synthesized by using the ultrasonic-assisted impregnation method. The physicochemical properties were comprehensively characterized via the BET, XRD, SEM, EDX, H2-TPR, O2-TPD, XPS and EPR techniques. The results showed that the catalytic activity of CuMnCex/Al2O3/Cor for toluene combustion was strongly affected by the Ce content. The CuMnCe2/Al2O3/Cor monolithic catalyst showed the best catalytic activity with toluene conversion of 90% at 263 °C under toluene concentration of 1 g/L and space velocity of 78000 mL/(g·h). Meanwhile, the well-dispersed CeO2 in the CuMn matrix not only improved the content of oxygen vacancies and the mobility of oxygen species, but also enhanced the low-temperature reducibility of the catalyst. Moreover, the CuMnCe2/Al2O3/Cor monolithic catalyst exhibited an excellent stability in the long-term test and cycle ability test.

     

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