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In Situ Raman Spectroscopy Study on Dissociation of Methane at High Temperatures and at High Pressures |
| CHEN Jin-Yang1;JIN Lu-Jiang1;DONG Jun-Ping2;ZHENG Hai-Fei3 |
| 1School of Environmental and Chemical Engineering, Shanghai University, Shanghai 2018002School of Sciences, Shanghai University, Shanghai 2004363School of the Earth and Space Sciences, Peking University, Beijing 100871 |
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| Cite this article: |
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CHEN Jin-Yang, JIN Lu-Jiang, DONG Jun-Ping et al 2008 Chin. Phys. Lett. 25 780-782 |
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Abstract We investigate the stability and dissociation of methane, which is the most abundant organic molecule in the universe, using diamond anvil cell (DAC) with in situ Raman spectroscopy up to 903K and 21GPa. At the temperatures of 793 and 723K and the corresponding pressures of 16.15 and 20.30GPa,
methane dissociates to form carbon `soot' and heavier hydrocarbons
involving C=C and C≡C bonds. However, if the pressure is not very high, methane remains stability up to the highest temperature of 903K of the work. The four symmetric C--H bonds of methane split at high temperatures and at high pressures, and there is at least one phase transition of crystalline symmetry from face centred cubic (fcc) to hexagonal close packed (hcp) before dissociation.
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| Keywords:
91.67.De
33.20.Fb
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Received: 11 October 2007
Published: 30 January 2008
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| PACS: |
91.67.De
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(Reactions and phase equilibria)
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33.20.Fb
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(Raman and Rayleigh spectra (including optical scattering) ?)
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