Hydrogen adsorption in zeolites A, X, Y and RHO

Langmi, Henrietta W.; Walton, Allan; Al-Mamouri, Malek; Johnson, Simon R.; Book, D. L.; Speight, J.D.; Edwards, Peter P.; Gameson, I.; Anderson, Paul A.; Harris, I.R.

doi:10.1016/s0925-8388(03)00368-2

Cited by 271 publications

(157 citation statements)

References 13 publications

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“…At liquid nitrogen temperature (77 K) the zeolites physisorb hydrogen in proportion to the specific surface area of the material. A maximum of 1.8 mass % of adsorbed hydrogen was found for a zeolite (NaY) with a specific surface area of 725 m 2 g −1 [20]. The low temperature physisorption (type I isotherm) of hydrogen in zeolites is in good agreement with the adsorption model mentioned above for nanostructured carbon.…”

Section: Experimental Verificationsupporting

confidence: 79%

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Model for the hydrogen adsorption on carbon nanostructures

et al. 2004

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The hydrogen sorption capacity of carbon nanostructures was for several years a very controversial subject. Theoretical models have been published demonstrating a great potential for a large hydrogen sorption capacity of carbon nanostructures. Here we present a simple empirical model where condensation of hydrogen as a monolayer at the surface of nanotubes as well as bulk condensation in the cavity of the tube is assumed. The maximum potential amount of hydrogen absorbed according to the model was calculated to be 2.28 × 10 −3 mass % S[m 2 g −1 ] = 3.0 mass % for the adsorption of a monolayer hydrogen at the surface. The condensation of hydrogen in the cavity of the tube leads to a potential absorption for single wall nanotubes starting at 1.5 mass % and increasing with the diameter of the tubes. The experimentally measured hydrogen capacity of the nanotube samples correlates with the B.E.T. specific surface area. The slope of the linear relationship is 1.5 × 10 −3 mass %/m 2 g −1 . Therefore, the extrapolated maximum discharge capacity of a carbon sample is 2 mass %. Furthermore, it can be concluded, that the hydrogen sorption mechanism is related to the surface of the sample, i.e. a surface adsorption process.

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Section: Experimental Verificationsupporting

confidence: 79%

“…The low temperature physisorption (type I isotherm) of hydrogen in zeolites is in good agreement with the adsorption model mentioned above for nanostructured carbon. The desorption isotherm followed the same path as the adsorption [20] which indicates that no pore condensation occurred.…”

Section: Experimental Verificationmentioning

confidence: 74%

Model for the hydrogen adsorption on carbon nanostructures

et al. 2004

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“…For this reason, other storage technologies are being investigated and one that is receiving much attention is the storage in porous materials. Several families of porous materials have been studied for this purpose: porous carbons, 3,4 metal organic frameworks, 5 zeolites, 6 clathrate hydrates, 7 and microporous organic polymers. 8 Targets to be achieved in the short term Focusing on the porous carbons, there is experimental [10][11][12] and theoretical evidence 4,[13][14][15][16][17] that hydrogen storage on clean porous carbon materials does not fulfill the recommended targets.…”

Section: Introductionmentioning

confidence: 99%

Is Spillover Relevant for Hydrogen Adsorption and Storage in Porous Carbons Doped with Palladium Nanoparticles?

et al. 2016

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Experiments have shown that the efficiency of nanoporous carbons to store hydrogen becomes enhanced by doping the material with metallic nanoparticles. In particular, doping with palladium has been used with success. The hypothesis to justify the enhancement has been that the Pd nanoparticles dissociate the hydrogen molecules and then the hydrogen atoms spill over the carbon substrate, where the hydrogen is retained. To test this hypothesis we have performed ab initio molecular dynamics simulations of the deposition of molecular hydrogen on Pd nanoparticles (Pd 6 and Pd 13 ) supported on graphene, which is a good model for the wall of a carbon nanopore. Three channels have been identified in the simulations: bouncing off the molecule, molecular adsorption, and dissociation of the molecule in two H atoms. The relative percentage of those channels is sensitive to the size of the Pd particle. Dissociation occurs more frequently on Pd 13 and it generally takes place on the lateral regions of the Pd particles.However, in our simulations we have not found a single case of H atoms or H 2 molecules spilling over the carbon substrate. We have also tested the situation when several H atoms are preadsorbed on the Pd 6 and Pd 13 particles and found that not a single dissociation event occurs on these H-saturated nanoparticles. These results lead us to cast strong doubts on the validity of the spillover mechanism for explaining the enhancement of hydrogen adsorption on porous carbons doped with transition metal nanoparticles.2

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“…One explanation could be that they actually did obtain elements or compounds that they could use in their metabolism by boring through the minerals. Zeolites are well known for their capacity to adsorb various elements and compounds like metals, hydrocarbons and molecular hydrogen within their crystal framework of molecular-sized channels (Sheta et al, 2003;Langmi et al, 2003). Zeolites are frequently used in industrial processes as ion exchangers, catalysts and molecular sieves, and it is most likely that zeolites in subseafloor settings adsorb compounds like Fe, CH 4 or H 2 from hydrothermal fluids which microorganisms can scavenge when dissolving the minerals.…”

Section: Microbe-mineral Interactionsmentioning

confidence: 99%

The Use of ESEM in Geobiology

Ivarsson¹,

Holmström²

2012

Scanning Electron Microscopy

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Today, an individual would be hard-pressed to find any science field that does not employ methods and instruments based on the use of fine focused electron and ion beams. Well instrumented and supplemented with advanced methods and techniques, SEMs provide possibilities not only of surface imaging but quantitative measurement of object topologies, local electrophysical characteristics of semiconductor structures and performing elemental analysis. Moreover, a fine focused e-beam is widely used for the creation of micro and nanostructures. The book's approach covers both theoretical and practical issues related to scanning electron microscopy. The book has 41 chapters, divided into six sections: Instrumentation, Methodology, Biology,

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Hydrogen adsorption in zeolites A, X, Y and RHO

Cited by 271 publications

References 13 publications

Model for the hydrogen adsorption on carbon nanostructures

Model for the hydrogen adsorption on carbon nanostructures

Is Spillover Relevant for Hydrogen Adsorption and Storage in Porous Carbons Doped with Palladium Nanoparticles?

The Use of ESEM in Geobiology

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