The cinchona alkaloids cinchonidine and cinchonine belong to the most efficient chiral modifiers for the noble metal-catalyzed enantioselective hydrogenation of C=O and C=C bonds. Under reaction conditions these modifiers are coadsorbed on the noble metal surface with hydrogen. Using density functional theory, we studied the effect of coadsorbed hydrogen on the adsorption mode of cinchonidine a...

Hybrid nanotubes of carbon and halloysite nanotubes (HNTs) with different carbon:HNTs ratio were hydrothermally synthesized from natural halloysite and sucrose. The samples display uniformly cylindrical hollow tubular structure with different morphologies. These hybrid nanotubes were concluded to be promising medium for physisorption-based hydrogen storage. The hydrogen adsorption capacity of p...

Electrical transport (resistance R and thermoelectric power S), Raman scattering, and hydrogen adsorption are used to study the interaction of hydrogen molecules with ropes of single-walled carbon nanotubes. The data are consistent with H2 physisorption under the experimental conditions investigated (4KoTo500K; 0.1 atmoPo20 atm). The response of S; R to 1 atm hydrogen at 500K is consistent with...

Nitrogen-doped graphene was recently synthesized and was reported to be a catalyst for hydrogen dissociative adsorption under a perpendicular applied electric field (F). In this work, the diffusion of H atoms on N-doped graphene, in the presence and absence of an applied perpendicular electric field, is studied using density functional theory. We demonstrate that the applied field can significa...

First-principles calculations are performed to investigate the adsorption of hydrogen onto Li-decorated hybrid boron nitride and graphene domains of (BN)(x)C(1-x) complexes with x = 1, 0.25, 0.5, 0.75, 0, and B0.125C0.875. The most stable adsorption sites for the nth hydrogen molecule in the lithium-decorated (BN)(x)C(1-x) complexes are systematically discussed. The most stable adsorption sites...

The present work refers to clay-graphene nanomaterials prepared by a green way using caramel from sucrose and two types of natural clays (montmorillonite and sepiolite) as precursors, with the aim of evaluating their potential use in hydrogen storage. The impregnation of the clay substrates by caramel in aqueous media, followed by a thermal treatment in the absence of oxygen of these clay-caram...

Second group metal dimers can replace the carbon atom in benzene to form metallabenzene (C5H6M2) compounds. These complexes possess some aromatic character and promising hydrogen adsorption properties. In this study, we investigated the aromatic character of these compounds using aromaticity indices and molecular orbital analysis. To determine the nature of interactions between hydrogen and the...

Density-functional theory is used to investigate hydrogen physisorption on a graphene layer and on single wall carbon nanotubes. Both external and internal adsorption sites of 9, 0 and 10, 0 carbon nanotubes have been studied with the hydrogen molecular axis oriented parallel or perpendicular to the nanotube wall. A range of hydrogen molecule binding sites has been examined and it is found that...

In this study, we have investigated radius dependence of hydrogen storage within armchair (n,n) single walled carbon nanotubes (SWCNT) in a square arrays. To this aim, we have employed equilibrium molecular dynamics (MD) simulation. Our simulations results reveal that radius of carbon nanotubes are an important and influent factor in hydrogen distribution inside carbon nanotubes and consequentl...