Enhanced ethanol production inside carbon-nanotube reactors containing catalytic particles

Abstract

Carbon nanotubes (CNTs) have well-defined hollow interiors and exhibit unusual mechanical and thermal stability as well as electron conductivity1. This opens intriguing possibilities to introduce other matter into the cavities2,3,4,5, which may lead to nanocomposite materials with interesting properties or behaviour different from the bulk6,7,8. Here, we report a striking enhancement of the catalytic activity of Rh particles confined inside nanotubes for the conversion of CO and H2 to ethanol. The overall formation rate of ethanol (30.0 mol mol−1Rh h−1) inside the nanotubes exceeds that on the outside of the nanotubes by more than an order of magnitude, although the latter is much more accessible. Such an effect with synergetic confinement has not been observed before in catalysis involving CNTs. We believe that our discovery may be of a quite general nature and could apply to many other processes. It is anticipated that this will motivate theoretical and experimental studies to further the fundamental understanding of the host–guest interaction within carbon and other nanotube systems.

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Figure 1: TEM image and catalytic performance of RMLF-in-CNTs in C2 oxygenate formation.
Figure 2: TEM images and particle size distribution of catalysts and their C2 oxygenate formation activities.
Figure 3: Raman spectra.
Figure 4: Schematic diagram showing ethanol production from syngas inside Rh-loaded carbon nanotubes.

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Acknowledgements

We thank Z. Tian and W. Weng from Xiamen University China for their help with Raman spectroscopy characterization and A. Goldbach for the discussion. We also acknowledge the financial support of the Natural Science Foundation of China and the Ministry of Science and Technology of China.

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Correspondence to Xinhe Bao.

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Supplementary information, figures S1-S6 and table S1 (PDF 4878 kb)

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Pan, X., Fan, Z., Chen, W. et al. Enhanced ethanol production inside carbon-nanotube reactors containing catalytic particles. Nature Mater 6, 507–511 (2007). https://doi.org/10.1038/nmat1916

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