Theoretical study of hydrogen adsorption in oxygen functionalized carbon slit pores

Gotzias, Anastasios; Tylianakis, Emmanuel; Froudakis, George E.; Steriotis, Theodore

doi:10.1016/j.micromeso.2011.10.011

Cited by 36 publications

(19 citation statements)

References 44 publications

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“…As demonstrated by many recent publications (Kumar et al 2012;Chen et al 2012;Gotzias et al 2012;Xiong and Keffer 2011;Liu et al 2009), detailed information about a material's crystallographic and atomic structure can be used in density functional theory and grand canonical Monte Carlo simulations to model both the heat of adsorption and the adsorbed phase density; however such work is typically still compared with experimental data taken at relatively low pressures (less than 10 MPa). As we will discuss in Sect.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen adsorption on microporous materials at ambient temperatures and pressures up to 50 MPa

2012

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High surface area microporous adsorbents are often proposed as potential hydrogen storage materials, although typically at 77 K and less than 5 MPa. In this study, we focus on conditions more suitable for automotive applications by investigating the storage capacities of microporous materials at 298 K and at pressures up to 50 MPa. In an effort to derive trends within and across material classes, we examined a wide range of materials with varying microstructures including the activated carbons AX-21, KUA-5, and MSC-30; a zeolite templated carbon; a hypercrosslinked polymer; and the Metal Organic Frameworks MOF-177, IRMOF-20, MIL-53, ZIF-8, and Cu 3 (btc) 2 . The peak excess adsorption of these materials ranged from 0.8-1.8 wt.%, although many did not reach their maximum capacity even at high pressures. However, the total volumetric storage gains over compressed hydrogen gas were quite low and, in many cases, negative. In addressing ambient temperature adsorption at significantly higher pressures than previously reported, our data confirms and extends the range of validity of several existing DFT calculations. Furthermore, our data suggest that, for both activated carbons and MOFs, factors other than specific surface area govern ambient temperature adsorption capacity. Contrary to some reports, the high fractions of sub-nanometer pores in some of the investigated MOFs did not appear to enhance the excess adsorption even at high pressures. For on-board applications with ambient temperature storage, significant enhancements to the attractive force at the materials' surface are required, beyond merely increasing specific surface area, or for MOFs, tuning of pore sizes.

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Section: Introductionmentioning

confidence: 99%

Hydrogen adsorption on microporous materials at ambient temperatures and pressures up to 50 MPa

2012

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“…The "perforated graphene" models [44] uses flat flakes not reconstructed at the edges and/or with regularly spaced pores [57]. Other studies are even simpler, including either the ideal slit-pore geometry [58][59][60] or defected [61]/rippled [62] multilayers. Finally, a number of models is based on periodic 3D structures, such as the open-carbon-frameworks [63,64] or the carbon honeycomb [65].…”

Section: Graphene-based Nano-porous Materials: Production and Computementioning

confidence: 99%

Engineering 3D Graphene-Based Materials: State of the Art and Perspectives

Bellucci

Tozzini

2020

Molecules

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Graphene is the prototype of two-dimensional (2D) materials, whose main feature is the extremely large surface-to-mass ratio. This property is interesting for a series of applications that involve interactions between particles and surfaces, such as, for instance, gas, fluid or charge storage, catalysis, and filtering. However, for most of these, a volumetric extension is needed, while preserving the large exposed surface. This proved to be rather a hard task, especially when specific structural features are also required (e.g., porosity or density given). Here we review the recent experimental realizations and theoretical/simulation studies of 3D materials based on graphene. Two main synthesis routes area available, both of which currently use (reduced) graphene oxide flakes as precursors. The first involves mixing and interlacing the flakes through various treatments (suspension, dehydration, reduction, activation, and others), leading to disordered nanoporous materials whose structure can be characterized a posteriori, but is difficult to control. With the aim of achieving a better control, a second path involves the functionalization of the flakes with pillars molecules, bringing a new class of materials with structure partially controlled by the size, shape, and chemical-physical properties of the pillars. We finally outline the first steps on a possible third road, which involves the construction of pillared multi-layers using epitaxial regularly nano-patterned graphene as precursor. While presenting a number of further difficulties, in principle this strategy would allow a complete control on the structural characteristics of the final 3D architecture.

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“…These groups are anchored on a graphitic surface and then we form the slit-shaped pore models. [53][54][55] As seen in Figure 1, the wetted layers of the slit pore along with the functional groups are defined atomistically. Solid-fluid interactions are expressed by a summation over all pair-wised LJ and electrostatic interactions that stem from that layer at both sides of the pore.…”

Section: Simulation Algorithm and Potential Modelmentioning

confidence: 99%

On the orientation of N₂and CO₂molecules adsorbed in slit pore models with oxidised graphitic surface

Gotzias

Charalambopoulou

Steriotis

2015

Molecular Simulation

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We report grand canonical Monte Carlo studies of nitrogen (77 K) and carbon dioxide (253 K) adsorbed in graphitic slit pores with surface oxygen functionalities. The analysis is focused on the molecular orientation within the adsorption layers and the influence of surface heterogeneity on molecular density distributions. The oxygen-containing surface functionalities act like additional adsorption sites along the graphitic basal plane that interacts also electrostatically with the fluid. Our simulations reveal that the molecular orientation of both adsorbate particles changes greatly upon increasing surface heterogeneity, while the effect of the pore size on the adsorption behaviour is also discussed. The detailed microscopic description of the adsorbed layer on oxygen modified carbon surfaces can be used to highlight thermodynamic features of gas adsorption on real surfaces such as layering transitions and surface area calculations.

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Theoretical study of hydrogen adsorption in oxygen functionalized carbon slit pores

Cited by 36 publications

References 44 publications

Hydrogen adsorption on microporous materials at ambient temperatures and pressures up to 50 MPa

Hydrogen adsorption on microporous materials at ambient temperatures and pressures up to 50 MPa

Engineering 3D Graphene-Based Materials: State of the Art and Perspectives

On the orientation of N₂and CO₂molecules adsorbed in slit pore models with oxidised graphitic surface

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Theoretical study of hydrogen adsorption in oxygen functionalized carbon slit pores

Cited by 36 publications

References 44 publications

Hydrogen adsorption on microporous materials at ambient temperatures and pressures up to 50 MPa

Hydrogen adsorption on microporous materials at ambient temperatures and pressures up to 50 MPa

Engineering 3D Graphene-Based Materials: State of the Art and Perspectives

On the orientation of N2and CO2molecules adsorbed in slit pore models with oxidised graphitic surface

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On the orientation of N₂and CO₂molecules adsorbed in slit pore models with oxidised graphitic surface