Adsorption of Ar and SO₂ on graphitized carbon black: The importance of functional groups

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• 作者：Z. Nickmand ; D. D. Do ; D. Nicholson ; S. F. Aghamiri
• 关键词：Adsorption ; Isosteric heats ; Ar ; Functional group ; Graphite surface ; GTCB ; SO2
• 刊名：Adsorption
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：23
• 期：1
• 页码：57-62
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Industrial Chemistry/Chemical Engineering; Surfaces and Interfaces, Thin Films; Engineering Thermodynamics, Heat and Mass Transfer;
• 出版者：Springer US
• ISSN：1572-8757
• 卷排序：23

文摘

Grand Canonical Monte Carlo (GCMC) simulation was used to determine the isotherms and isosteric heats of argon and the strongly polar molecule, sulphur dioxide (SO₂), adsorbed at 78 and 273 K on a graphitized thermal carbon black (GTCB) surface with functional groups. The functional group, was modelled as oxygen atoms bonded to a C-atom in the graphene surface, since these have been shown to be retained after thermal treatment of GTCB. The simulated adsorption isotherms and isosteric heats of argon and SO₂ were compared with the experimental data. It is shown that, while functional groups do not affect the adsorption of argon, adsorption of SO₂ is very sensitive to their concentration, especially at low loadings, where the adsorption is dominated by the electrostatic interaction between SO₂ and the functional group. This is confirmed by analysis of the various contributions to the isosteric heat: (1) fluid-functional group interactions, (2) fluid-basal plane interactions, and (3) fluid–fluid interactions. Finally, we investigated the orientation of SO₂ in the first and second layers depends on loading as well as on the distance of the molecule from the surface.