The influence of carbon surface oxygen groups on Dubinin–Astakhov equation parameters calculated from CO2 adsorption isotherm

Furmaniak, S., Terzyk, A. P., Gauden, P. A., Harris, P. J. F. and Kowalczyk, P. (2010) The influence of carbon surface oxygen groups on Dubinin–Astakhov equation parameters calculated from CO2 adsorption isotherm. Journal of Physics: Condensed Matter, 22 (8). 085003. ISSN 0953-8984 doi: 10.1088/0953-8984/22/8/085003

Abstract/Summary

We present the results of a systematic study of the influence of carbon surface oxidation on Dubinin–Astakhov isotherm parameters obtained from the fitting of CO2 adsorption data. Using GCMC simulations of adsorption on realistic VPC models differing in porosity and containing the most frequently occurring carbon surface functionalities (carboxyls, hydroxyls and carbonyls) and their mixtures, it is concluded that the maximum adsorption calculated from the DA model is not strongly affected by the presence of oxygen groups. Unfortunately, the same cannot be said of the remaining two parameters of this model i.e. the heterogeneity parameter (n) and the characteristic energy of adsorption (E0). Since from the latter the pore diameters of carbons are usually calculated, by inverse-type relationships, it is concluded that they are questionable for carbons containing surface oxides, especially carboxyls.

Item Type	Article
URI	https://centaur.reading.ac.uk/id/eprint/19568
Identification Number/DOI	10.1088/0953-8984/22/8/085003
Refereed	Yes
Divisions	Interdisciplinary centres and themes > Nanoscience and Materials Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Electron Microscopy Laboratory (CAF)
Publisher	Institute of Physics Publishing
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