Experimental and Theoretical Study on the Ethane and Acetylene Formation from Electron Irradiation of Methane Ices


In this work we present an experimental and theoretical study on the formation of ethane and acetylene from solid methane condensed at 20 K and irradiated with a 500 - 3000 eV electron beam. The experiments were monitored with Thermal Desorption Spectroscopy. We observe that the electron irradiation induced a dehydrogenation of methane and a consequent formation of CHx (x = 1, 2, 3) fragments. Furthermore, in the solid during irradiation, a simple recombinetion reaction in the solid between two adjacent CHx molecules may form HC≡CH, H2C=CH2, and H3C-CH3 with a triple, double, and single carbon-carbon bond, respectively. The formed amount of ethane and acetylene increases with irradiation time and reaches a saturation value.


Share and Cite:

M. Barberio, R. Vasta, P. Barone, G. Manicò and F. Xu, "Experimental and Theoretical Study on the Ethane and Acetylene Formation from Electron Irradiation of Methane Ices," World Journal of Condensed Matter Physics, Vol. 3 No. 1, 2013, pp. 14-20. doi: 10.4236/wjcmp.2013.31003.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] E. Garand and P. A. Rowntree, “The Mechanism of Hydrogen Formation Induced by Low-Energy Electron Irradiation of Hexadecanethiol Self-Assembled Monolayers,” The Journal of Physical Chemistry B, Vol. 109, No. 26, 2005, pp. 12927-12934. doi:10.1021/jp050817k
[2] H. F. Winters, “Dissociation of Ethane by Electron Impact,” Chemical Physics, Vol. 36, No. 3, 1979, pp. 353364. doi:10.1016/0301-0104(79)85019-3
[3] C. J. Bennet, C. S. Jamieson, Y. Osamura, R. I. Kaiser, Laboratory Studies on the Irradiation of Methane in Interstellar, Cometary, and Solar System Ices,” The Astrophysical Journal, Vol. 653, No. 1, 2006, p. 792. doi:10.1086/508561
[4] Scheffler and Elsasser, “Physics of the Galaxy and Interstellar Matter,” Springer, Berlin, 1988.
[5] D. C. B. Whittet, “Observations of Molecular Ices,” In: T. J. Millar and D. A. Williams, Eds., Dust and Chemistry in Astronomy, Cambridge University Press, Cambridge, 1993, p. 201.
[6] Hollenbach and Thronson, “Interstellar Processes,” Proceedings of the Symposium on Interstellar Processes, Grand Teton National Park, 1-7 July 1986, Vol. 134 No. ,
[7] W. A. Schutte, “Production of Organic Molecules in Interstellar Ices,” Advances in Space Research, Vol. 30, No. 6, 2002, pp. 1409-1417. doi:10.1016/S0273-1177(02)00500-8
[8] R. I. Kaiser and K. Roessler, “Theoretical and Laboratory Studies on the Interaction of Cosmic-Ray Particles with Interstellar Ices. III. Suprathermal Chemistry-Induced Formation of Hydrocarbon Molecules in Solid Methane (CH4), Ethylene (C2H4), and Acetylene (C2H2),” The Astrophysical Journal, Vol. 503, No. 2, 1998, p. 959. doi:10.1086/306001
[9] A. Wada, N. Mochizuki and K. Hiraoka, “Methanol Formation from Electron-Irradiated Mixed H2O/CH4 Ice at 10 K,” The Astrophysical Journal, Vol. 644, No. 1, 2006, p. 300. doi:10.1086/503380
[10] Zheng, Jewitt, Osamura and Kaiser, “Formation of Nitrogen and Hydrogen-bearing Molecules in Solid Ammonia and Implications for Solar System and Interstellar Ices,” The Astrophysical Journal, Vol. 674, No. 2, (2008) pp. 1242. doi:10.1086/523783
[11] P. Ehrenfreund, S. B. Charneley and D. Wooden, “Comets II,” University of Arizona Press, Tucson, 2004.
[12] T. Y. Brooke, A. T. Tokunaga, H. A. Weaver, J. Crovisier, D. Bockelée-Morvan and D. Crisp, “Detection of Acetylene in the Infrared Spectrum of Comet Hyakutak,” Nature, Vol. 383, 1996, pp. 606-608. doi:10.1038/383606a0
[13] http://www.sisweb.com/referenc/source/exactmas.htm
[14] M. Barberio, P. Barone, R. Vasta, G. Manicò and F. Xu, “Formation of Molecular Nitrogen and Diazene by Electron Irradiation of Solid Ammonia,” Thin Solid Film, Vol. 520, No. 16, 2012, pp. 5479-5481. doi:10.1016/j.tsf.2012.03.112
[15] T. Shirai, et al., “Analytic Cross Sections for Electron Collisions with Hydrocarbons: CH4, C2H6, C2H4, C2H2, C3H8, and C3H6,” Atomic Data and Nuclear Data Tables, Vol. 80, No. 2, 2002, pp. 147-204. doi:10.1006/adnd.2001.0878
[16] D. J. Alberas-Sloan and J. M. White, “Low-Energy Electron Irradiation of Methane on Pt(111),” Surface Science, Vol. 365 No. 2, 1996, pp. 212-228. doi:10.1016/0039-6028(96)00720-0
[17] http://xdb.lbl.gov/Section3/Sec_3-2.html
[18] M. A. Huels, P. C. Dugal and L. Sanche, “Degradation of Functionalized Alkanethiolate Monolayers by 0 18 eV Electrons,” Journal of Chemical Physics, Vol. 118, No. 24, 2003, pp. 11168-11179. doi:10.1063/1.1574791
[19] D. Drouin, A. R. Couture, D. Joly, X. Tastet, V. Aimez and R. Gauvin, “CASINO V2.42—A Fast and Easy-toUse Modeling Tool for Scanning Electron Microscopy and Microanalysis Users,” Scanning, Vol. 29, No. 3, 2007, p. 92.
[20] P. Hovington, D. Drouin and R. Gauvin, “CASINO: A New Monte Carlo Code in C Language for Electron Beam intEraction—Part I: Description of the Program,” Scanning, Vol. 19, No. 1, 1997, pp. 1-14. doi:10.1002/sca.4950190101

Copyright © 2022 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.