高等学校化学学报 ›› 2014, Vol. 35 ›› Issue (11): 2397.doi: 10.7503/cjcu20140481

• 物理化学 • 上一篇    下一篇

膨胀石墨负载钯纳米颗粒催化六价铬还原反应

魏英祥, 涂伟霞()   

  1. 北京化工大学, 有机无机复合材料国家重点实验室, 北京 100029
  • 收稿日期:2014-05-23 出版日期:2014-11-10 发布日期:2014-10-09
  • 作者简介:联系人简介: 涂伟霞, 女, 博士, 副教授, 主要从事纳米催化剂的合成与应用研究. E-mail:tuwx@mail.buct.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 21106006)和中央高校基本科研业务费专项资金(批准号: ZZ1205)资助

Reduction of Hexavalent Chromium over the Expanded Graphite Supported Palladium Nanocatalyst

WEI Yingxiang, TU Weixia*()   

  1. State Key Laboratory of Organic-inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2014-05-23 Online:2014-11-10 Published:2014-10-09
  • Contact: TU Weixia E-mail:tuwx@mail.buct.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21106006) and the Fundamental Research Funds for the Central Universities, China(No.ZZ1205)

摘要:

采用高分子辅助的浸渍还原法, 制备得到膨胀石墨(EG)负载的纳米钯催化剂(Pd-EG), 采用X射线衍射(XRD)、 透射电子显微镜(TEM)、 X射线光电子能谱(XPS)等手段对催化剂组成、 结构、 形貌和价态进行了表征, 并考察了Pd-EG催化剂在六价铬还原反应中的活性. 结果表明, 催化剂中纳米钯颗粒均匀分散在膨胀石墨上, 平均粒径为4.37 nm, 金属负载量质量分数为0.446%. 该催化剂对六价铬还原反应具有良好的催化性能, 可将六价铬完全转化为三价铬, 在pH=4.0及45 ℃条件下反应转化频率(TOF)达到3186 h-1; 催化剂经过多次重复使用后的活性仍保持稳定.

关键词: 膨胀石墨, 钯, 纳米颗粒, 六价铬, 催化, 还原反应

Abstract:

Expanded graphite(EG) supported palladium nanocatalysts(Pd-EG) were synthesized by wet-impregnation reduction method with the aid of a polymer stabilizer. The catalysts were characterized by various techniques including X-ray diffraction(XRD), transmission electron microscope(TEM) and X-ray photoelectron spectroscopy(XPS). The catalytic activities of the synthesized Pd-EG nanocatalysts were evaluated for the reduction of Cr(Ⅵ). The results indicated that the Pd loading of Pd-EG nanocatalysts was 0.446%(mass fraction) in the form of Pd nanoparticles with an average diameter of 4.37 nm. The Pd-EG nanocatalysts show high catalytic activity in the complete reduction of Cr(Ⅵ) to Cr(Ⅲ) with a turn-over frequency(TOF) of 3186 h-1 at pH=4.0 and 45 ℃. The Pd-EG catalysts exhibit efficient and stable catalytic performance even after several times of recycles.

Key words: Expanded graphite, Palladium, Nanoparticles, Hexavalent chromium, Catalysis, Reduction

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