Importance of molecular shape in the adsorption of nitrogen, carbon dioxide and methane on surfaces and in confined spaces

Do, D. D., Junpirom, S., Nicholson, D. and Do, H. D. (2010) Importance of molecular shape in the adsorption of nitrogen, carbon dioxide and methane on surfaces and in confined spaces. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 353 1: 10-29. doi:10.1016/j.colsurfa.2009.10.021


Author Do, D. D.
Junpirom, S.
Nicholson, D.
Do, H. D.
Title Importance of molecular shape in the adsorption of nitrogen, carbon dioxide and methane on surfaces and in confined spaces
Journal name Colloids and Surfaces A: Physicochemical and Engineering Aspects   Check publisher's open access policy
ISSN 0927-7757
Publication date 2010-01-01
Year available 2010
Sub-type Article (original research)
DOI 10.1016/j.colsurfa.2009.10.021
Volume 353
Issue 1
Start page 10
End page 29
Total pages 20
Place of publication Amsterdam, Netherlands
Publisher Elsevier Science Bv
Collection year 2011
Language eng
Subject 250100 Physical Chemistry (incl. Structural)
Abstract The importance of shape in the adsorption of nitrogen, carbon dioxide and methane (common molecular probes for solid characterization) on surfaces and in confined spaces is investigated for its effects on the adsorption capacity and isosteric heat. We study the possibility of using an equivalent pseudo-sphere model to describe the potential energy of interaction of these molecular probes. On a flat open surface, we find that the equivalent pseudo-sphere model describes adsorption of these species sufficiently well. However, in the confined space of pores, especially pores that accommodate three layers or less, the pseudo-sphere model describes the adsorption badly because of the geometrical constraint on the molecular packing. It is recommended that to study adsorption properly in small pores, potential models that correctly describe molecular shape should be used. In characterization, pseudo-sphere models are commonly used to generate the kernels (local isotherms) for the determination of pore size distribution which can lead to misleading results. We illustrate this with an example to show that the wrong pore size distribution results if pseudo-sphere kernels are used. (C) 2009 Elsevier B.V. All rights reserved.
Keyword Adsorption
Molecular shape
Surfaces
Confined space
Micropore Size Distribution
Activated Carbon
Pore-size
Potential models
Monte-carlo
Slit pores
simulation
phase
Black
Adsorbents
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Available online 24 October, 2009.

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemical Engineering Publications
Official 2011 Collection
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 10 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 11 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sun, 07 Feb 2010, 10:07:16 EST