物理化学学报 >> 2017, Vol. 33 >> Issue (8): 1681-1688.doi: 10.3866/PKU.WHXB201704192

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Pd/γ-Al2O3催化剂催化氧化邻-二甲苯

胡凌霄1,2,王莲1,2,王飞1,2,张长斌1,2,*(),贺泓1,2,3,*()   

  1. 1 中国科学院生态环境研究中心,环境模拟与污染控制国家重点联合实验室,北京100085
    2 中国科学院大学,北京100049
    3 中国科学院城市环境研究所,福建厦门361021
  • 收稿日期:2016-12-28 发布日期:2017-06-14
  • 通讯作者: 张长斌,贺泓 E-mail:cbzhang@rcees.ac.cn;honghe@rcees.ac.cn
  • 基金资助:
    优秀青年基金(21422706);国家自然科学基金(51678560)

Catalytic Oxidation of o-Xylene over Pd/γ-Al2O3 Catalysts

Ling-Xiao HU1,2,Lian WANG1,2,Fei WANG1,2,Chang-Bin ZHANG1,2,*(),Hong HE1,2,3,*()   

  1. 1 State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P. R. China
    2 University of Chinese Academy of Sciences, Beijing 100049, P. R. China
    3 Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, Fujian Province, P. R. China
  • Received:2016-12-28 Published:2017-06-14
  • Contact: Chang-Bin ZHANG,Hong HE E-mail:cbzhang@rcees.ac.cn;honghe@rcees.ac.cn
  • Supported by:
    The project was supported by the National Natural Science Foundation for Excellent Young Scholars, China(21422706);National Natural Science Foundation of China(51678560)

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摘要：

利用纳米γ-Al2O3（10 nm）和普通γ-Al2O3（200-300 nm），采用浸渍法制备了1%（w）Pd/γ-Al2O3催化剂，考察了其催化氧化邻-二甲苯的性能以及催化剂的活性在氢气还原前后的区别。实验结果发现1%（w）Pd/γ-Al2O3（nano）在H2还原后催化氧化邻-二甲苯的活性最高，T90为150℃。利用X射线衍射（XRD）、比表面积（BET）、透射电镜（TEM）、X射线光电子能谱（XPS）等表征手段，研究了1%（w）Pd/γ-Al2O3催化剂物性结构与催化性能之间的构效关系。结果表明，还原态Pd是H2还原后催化剂催化氧化邻-二甲苯的活性物种；Pd的颗粒大小与催化剂活性有显著的关系，小粒径有利于催化剂活性提高；纳米γ-Al2O3载体与Pd之间的相互作用强，有利于Pd的粒径控制和分散，从而提高1%（w）Pd/γ-Al2O3（nano）催化剂的活性。

关键词: γ-Al2O3, 贵金属催化剂, 催化氧化, 邻-二甲苯

Abstract:

1% (w)Pd/γ-Al2O3 catalysts were prepared by the impregnation method using nano γ-Al2O3 (10 nm) and γ-Al2O3 (200-300 nm) as support materials. The catalysts were tested for catalytic oxidation of o-xylene and the difference of catalyst activity before and after hydrogen reduction was investigated. The results indicate that 1% (w)Pd/γ-Al2O3 (nano) has the highest catalytic activity for o-xylene oxidation after H2 reduction, and the T90 (The temperature of conversion rate of o-xylene reaches 90%) was 150℃. The structure-activity relationships of the catalysts were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), while the specific surface area was determined using the Brunauer-Emmett-Teller (BET) isotherm. The results show that the reduced Pd is the active species for catalytic oxidation of o-xylene. Pd particle size has a significant influence on the catalyst activity and a small Pd particle size is favorable. There is a strong interaction between the supporter (nano γ-Al2O3) and the Pd species, which facilitates the particle size control and Pd dispersion, thereby increasing the catalyst activity of the 1% (w)Pd/γ-Al2O3(nano) catalyst.

Key words: γ-Al2O3, Noble metal catalyst, Catalytic oxidation, o-Xylene