A GCMC simulation and experimental study of krypton adsorption/desorption hysteresis on a graphite surface

Prasetyo, Luisa; Horikawa, Toshihide; Phadungbut, Poomiwat; Tan, Shiliang; D, D; Nicholson, D.

doi:10.1016/j.jcis.2016.06.033

Cited by 17 publications

(11 citation statements)

References 29 publications

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“…Computer simulation studies of adsorption of gases on graphite using the homogeneous continuum 10-4-3 model 1 have been used to investigate the mechanism of adsorption for a number of single and multisite molecules, for example, argon, 2-4 methane, 5 krypton, 6,7 nitrogen, 8,9 carbon dioxide, 10 benzene, 11 ethane, 12 ethylene, 12 propylene, 13 carbon tetrachloride, 14 n-butane, n-pentane, n-hexane, 15 methanol, 16,17 ethanol, 17 and ammonia. 18 This model assumes that graphite is a uniformly homogeneous continuum solid, and its derivation implies the following assumptions: (1) the solid is built from stacked, equally spaced graphene layers, (2) there is an infinite number of layers, and (3) the carbon atom molecular parameters are invariant for all layers (collision diameter a) Author to whom correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

An improved model for N2 adsorption on graphitic adsorbents and graphitized thermal carbon black—The importance of the anisotropy of graphene

Prasetyo

Tan

Zeng

et al. 2017

The Journal of Chemical Physics

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Computer simulations of N 2 adsorption on graphite frequently use the 10-4-3 equation with Steele's molecular parameters to describe the dispersive-repulsive interaction between a molecule and graphite. This model assumes that graphite is a uniformly homogeneous continuum solid, and its derivation implies the following assumptions: (1) the solid is built from stacked, equally spaced graphene layers, (2) there is an infinite number of layers, and (3) the carbon atom molecular parameters are invariant for all layers (collision diameter of 0.34 nm and reduced well depth of interaction energy of 28 K). Despite the fact that this model can give an acceptable description of experimental data for this system, there are experimental observations that simulation results fail to account for. First, the isotherm does not exhibit a step in the sub-monolayer coverage region at 77 K, which is attributed to a transition from the supercritical state of the adsorbate to the commensurate state, and therefore fails to reproduce the cusp and heat spike in the experimental isosteric heat curve versus loading at close to monolayer coverage. Second, the simulation results overpredict the experimental data in the multilayer region. These discrepancies suggest that (1) the absence of lateral corrugation in the 10-4-3 potential misses the commensurate to incommensurate transition and (2) the long-range solid-fluid potential, experienced by the second and higher layers onwards, is too strong. Here we examine a revised graphite potential model that incorporates three features absent from the 10-4-3 model: (1) an energetic corrugation of the potential arising from the discrete atom structure of the adsorbent, (2) the unequal spacing of the graphene layers due to the anisotropic force field acting on graphene layers at the surface, and (3) the different polarizabilities of carbon atoms in graphite, parallel and normal to the graphene surface. These features are corroborated by a number of experimental measurements and quantum-mechanical calculations: (1) the Low-Energy Electron Diffraction (LEED) and Surface-Extended X-ray Absorption Fine Structure (SEXAFS) experiments show that the first adsorbate layer is smaller than predicted by the 10-4-3 model with the traditional molecular parameters suggested by Steele, and (2) the potential well depth for atoms in graphene is stronger than for C-atoms in graphite. The simulation results using this revised graphite model give an improved description of the fine features of adsorption of N 2 on graphite: the sub-step in the first layer of the isotherm, the spike in the isosteric heat curve versus loading, and the coverage at higher loadings.

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Section: Introductionmentioning

confidence: 99%

An improved model for N2 adsorption on graphitic adsorbents and graphitized thermal carbon black—The importance of the anisotropy of graphene

Prasetyo

Tan

Zeng

et al. 2017

The Journal of Chemical Physics

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“…For example, the adsorption of Ar/Mg (D*=3.5) 92 shows non-wetting and pre-wetting transitions for temperature above the bulk triple point of Ar whereas Ar/Graphite (D*=9) always shows continuous wetting for the same temperature range 43,49,109 . This contrast of behaviour is also observed for the adsorption of other simple gases on alkali metals 86,92,93,97,98,102 and graphite 26,28,44,110 . Macroscopically, the wetting/non-wetting is determined from the contact angle between the liquid film and solid substrate at the saturation vapour pressure P0 88 .…”

Section: Adsorption Of Polar Gases On Gtcbsupporting

confidence: 53%

“…Experimental studies of non-associating fluids (e.g. Xe [21][22][23][24] , Ne [25][26][27] , Kr 22,[28][29][30] , Ar [31][32][33] , N2 [33][34][35] , the oxides of carbon 36,37 and hydrocarbons, including CH4 38,39 , C2H4 40,41 and benzene 42 ) have revealed that these simple fluids do not interact specifically with functional groups and typically will adsorb on the basal plane with a molecular layering process 21,38,[43][44][45][46][47][48][49] due to the dominance of the fluid-basal plane interaction [50][51][52][53][54][55] over the fluid-fluid interaction. The characteristic features of adsorption on homogeneous surface include: (1) existence of a well-defined Henry constant as manifested by a slope of unity in the plot of logarithm of the amount adsorbed versus the logarithm of pressure over the low pressure region 56 .…”

Section: Adsorption Of Non-polar Gases On Gtcbmentioning

confidence: 99%

Fundamental study of adsorption of non-polar and polar fluids on hydrophobic ordered solids

Prasetyo¹

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Adsorption of gases on solids has been a subject of interest due to its increasing use as an economical process for separation and purification in chemical and biochemical industries. To optimise these processes, a good fundamental understanding of adsorption is required. With the advancement of technology, a better understanding of the microscopic mechanism of various adsorption phenomena can be achieved with molecular simulation. This thesis

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“…There is an initial decrease in the SF contribution, a trend that is not commonly observed for simple gases (i.e. Ar [30], Kr [31]),…”

Section: Decomposition Of Isosteric Heat Profilementioning

confidence: 78%

On the resolution of constant isosteric heat of propylene adsorption on graphite in the sub-monolayer coverage region

Prasetyo

Razak

Duong

et al. 2017

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Highlights Resolution of isosteric heat versus loading for propylene adsorption on graphite  Importance of the solid-fluid (SF) interaction with orientation of propylene  Extensive simulation study of propylene adsorption with various potential models  The dominance of adsorbate interactions over the SF interactions AbstractAn early experimental study by Bezus, Dreving and Kiselev [1] on the adsorption of propylene on Spheron-6 carbon black (graphitized at ~3000C) reported a plot of constant isosteric heat versus loading in the sub-monolayer region. This contrasts with their report of a linear increase in isosteric heat for propane, a similar molecule to propylene. In this paper, we report extensive Grand Canonical Monte Carlo (GCMC) simulations and a high-resolution experimental study of propylene adsorption on Carbopack F, a highly graphitized thermal carbon black, over the same temperature range studied by Bezus et al. From this combined simulation and experimental study we conclude that propylene also shows a linear increase in the isosteric heat versus loading in the sub-monolayer region, indicating that the linear increase in the fluid-fluid interaction in this region more than compensates for the decrease in the solid-fluid interaction that results from the change in orientation of the adsorbate molecules. Our study contradicts the propylene results of Bezus et al., and careful

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A GCMC simulation and experimental study of krypton adsorption/desorption hysteresis on a graphite surface

Cited by 17 publications

References 29 publications

An improved model for N2 adsorption on graphitic adsorbents and graphitized thermal carbon black—The importance of the anisotropy of graphene

An improved model for N2 adsorption on graphitic adsorbents and graphitized thermal carbon black—The importance of the anisotropy of graphene

Fundamental study of adsorption of non-polar and polar fluids on hydrophobic ordered solids

On the resolution of constant isosteric heat of propylene adsorption on graphite in the sub-monolayer coverage region

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