物理化学学报 >> 2015, Vol. 31 >> Issue (7): 1383-1390.doi: 10.3866/PKU.WHXB201504292

催化和表面科学 上一篇    下一篇

石墨烯负载MnOx催化剂的制备及其低温NH3-SCR活性

焦金珍1, 李时卉1, 黄碧纯1,2   

  1. 1 华南理工大学环境与能源学院, 广州510006;
    2 华南理工大学工业聚集区污染控制与生态修复教育部重点实验室, 广州510006
  • 收稿日期:2015-01-07 修回日期:2015-04-27 发布日期:2015-07-08
  • 通讯作者: 黄碧纯 E-mail:cebhuang@scut.edu.cn
  • 基金资助:

    国家自然科学基金(51478191)资助项目

Preparation of Manganese Oxides Supported on Graphene Catalysts and Their Activity in Low-Temperature NH3-SCR

JIAO Jin-Zhen1, LI Shi-Hui1, HUANG Bi-Chun1,2   

  1. 1 College of Environment and Energy, South China University of Technology, Guangzhou 510006, P. R. China;
    2 Key Laboratory of the Ministry of Education for Pollution Control and Ecosystem Restoration in Industry Clusters, South China University of Technology, Guangzhou 510006, P. R. China
  • Received:2015-01-07 Revised:2015-04-27 Published:2015-07-08
  • Contact: HUANG Bi-Chun E-mail:cebhuang@scut.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51478191).

摘要:

通过改进的Hummers法合成氧化石墨烯(GO), 随后采用水热法制备石墨烯负载锰氧化物(MnOx/GR)催化剂. 考察了催化剂的低温NH3选择性催化还原(NH3-SCR)去除NOx的性能, 并通过傅里叶变换红外(FTIR)光谱, 拉曼(Raman)光谱, X射线衍射(XRD), 透射电镜(TEM), N2吸附-脱附, X射线光电子能谱(XPS)及H2程序升温还原(H2-TPR)等多种表征手段对催化剂的结构及NH3-SCR性能进行分析. 结果显示, 不同MnOx负载量的MnOx/GR催化剂均展现了较好的低温SCR催化活性, 且在负载量为20%(w)时活性最优. 表征分析结果表明, 制备的GO表面含有丰富的含氧基团, 锰可以通过与含氧基团结合而负载到GO上; MnOx/GR催化剂中MnOx以纳米颗粒分散于石墨烯载体表面, 且以多种氧化物(MnO、Mn3O4和MnO2)共同存在; 负载量为20%(w)的催化剂中高价锰和表面吸附氧含量增加, 低温区氧化还原能力增强及活性位点数量增加是其SCR活性提高的原因.

关键词: 选择性催化还原, 氮氧化物, 石墨烯, 氧化石墨烯, 锰氧化物

Abstract:

Graphene oxide (GO) was synthesized using an improved Hummers method. Subsequently, catalysts of manganese oxides (at varying loadings) supported on graphene (MnOx/GR) were prepared by hydrothermal reaction for application in the selective catalytic reduction (SCR) of NOx with NH3 at low temperatures. The structural properties and catalytic performance were evaluated by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption, X-ray photoelectron spectroscopy (XPS), and H2 temperature-programmed reduction (H2-TPR). The characterization results indicated that abundant functional groups existed on the surface of the prepared GO that could combine with manganese during preparation of the catalysts. Manganese oxide entities, with different crystallinities (MnO, Mn3O4, or MnO2), were dispersed on the surface of graphene. The results of the catalytic studies showed that the MnOx/GR catalysts prepared with different MnOx loadings all exhibited excellent low-temperature SCR activities. The catalyst with 20%(w) MnOx displayed the best activity, which was attributed to the high content of high-valent manganese and oxygen adsorbed onto the catalyst surface, as well as to the enhancement in redox abilities and the addition of active sites at low temperatures.

Key words: Selective catalytic reduction, Nitrogen oxide, Graphene, Graphene oxide, Manganese oxide

MSC2000: 

  • O643