能源化学(英文) ›› 2013, Vol. 22 ›› Issue (2): 312-320.

• Articles • 上一篇    下一篇

Purified oxygen- and nitrogen-modified multi-walled carbon nanotubes as metal-free catalysts for selective olefin hydrogenation

Peirong Chena, Ly May Chewa, Aleksander Kostkab, Kunpeng Xiea, Martin Muhlera, Wei Xiaa   

  1. a. Laboratory of Industrial Chemistry, Ruhr-University Bochum, 44780 Bochum, Germany;
    b. Department of Microstructure Physics and Alloy Design, Max-Planck-Institute for Iron Research, 40237 Düsseldorf, Germany
  • 收稿日期:2012-11-05 修回日期:2012-12-24 出版日期:2013-03-20 发布日期:2013-04-04
  • 通讯作者: Wei Xia
  • 基金资助:
    This work was supported by the German Federal Ministry of Education and Research (BMBF) for the CarboKat Project (03X0204D) within the scope of the Inno.CNT Alliance.

Purified oxygen- and nitrogen-modified multi-walled carbon nanotubes as metal-free catalysts for selective olefin hydrogenation

Peirong Chena, Ly May Chewa, Aleksander Kostkab, Kunpeng Xiea, Martin Muhlera, Wei Xiaa   

  1. a. Laboratory of Industrial Chemistry, Ruhr-University Bochum, 44780 Bochum, Germany;
    b. Department of Microstructure Physics and Alloy Design, Max-Planck-Institute for Iron Research, 40237 Düsseldorf, Germany
  • Received:2012-11-05 Revised:2012-12-24 Online:2013-03-20 Published:2013-04-04
  • Supported by:
    This work was supported by the German Federal Ministry of Education and Research (BMBF) for the CarboKat Project (03X0204D) within the scope of the Inno.CNT Alliance.

摘要: Oxygen- and nitrogen-functionalized carbon nanotubes (OCNTs and NCNTs) were applied as metal-free catalysts in selective olefin hydrogenation. A series of NCNTs was synthesized by NH3 post-treatment of OCNTs. Temperature-programmed desorption, N2 physisorption, Raman spectroscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were employed to characterize the surface properties of OCNTs and NCNTs, aiming at a detailed analysis of the type and amount of oxygen- and nitrogen-containing groups as well as surface defects. The gas-phase treatments applied for oxygen and nitrogen functionalization at elevated temperatures up to 600 ℃ led to the increase of surface defects, but did not cause structural damages in the bulk. NCNTs showed a clearly higher activity than the pristine CNTs and OCNTs in the hydrogenation of 1,5-cyclooctadiene, and also the selectivity to cyclooctene was higher. The favorable catalytic properties are ascribed to the nitrogen-containing surface functional groups as well as surface defects related to nitrogen species. In contrast, oxygen-containing surface groups and the surface defects caused by oxygen species did not show clear contribution to the hydrogenation catalysis.

关键词: multi-walled carbon nanotubes, nitrogen-containing functional groups, oxygen-containing functional groups, metal-free catalyst, selective olefin hydrogenation

Abstract: Oxygen- and nitrogen-functionalized carbon nanotubes (OCNTs and NCNTs) were applied as metal-free catalysts in selective olefin hydrogenation. A series of NCNTs was synthesized by NH3 post-treatment of OCNTs. Temperature-programmed desorption, N2 physisorption, Raman spectroscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were employed to characterize the surface properties of OCNTs and NCNTs, aiming at a detailed analysis of the type and amount of oxygen- and nitrogen-containing groups as well as surface defects. The gas-phase treatments applied for oxygen and nitrogen functionalization at elevated temperatures up to 600 ℃ led to the increase of surface defects, but did not cause structural damages in the bulk. NCNTs showed a clearly higher activity than the pristine CNTs and OCNTs in the hydrogenation of 1,5-cyclooctadiene, and also the selectivity to cyclooctene was higher. The favorable catalytic properties are ascribed to the nitrogen-containing surface functional groups as well as surface defects related to nitrogen species. In contrast, oxygen-containing surface groups and the surface defects caused by oxygen species did not show clear contribution to the hydrogenation catalysis.

Key words: multi-walled carbon nanotubes, nitrogen-containing functional groups, oxygen-containing functional groups, metal-free catalyst, selective olefin hydrogenation