scholarly journals Anomalous hydrogen adsorption sites found for the c(2×2)-3H phases formed on the Re(101̄0) and Ru(101̄0) surfaces

1998 ◽  
Vol 108 (20) ◽  
pp. 8671-8679 ◽  
Author(s):  
R. Döll ◽  
L. Hammer ◽  
K. Heinz ◽  
K. Bedürftig ◽  
U. Muschiol ◽  
...  
Keyword(s):  
Hydrogen Adsorption ◽  
Adsorption Sites

Investigation, using density function theory, of coverage of the kaolinite (001) surface during hydrogen adsorption

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 393-402 ◽  
Author(s):  
Jian Zhao ◽  
Wei Gao ◽  
Zhi-Gang Tao ◽  
Hong-Yun Guo ◽  
Man-Chao He
Keyword(s):  
Density Functional ◽  
Hydrogen Adsorption ◽  
Function Theory ◽  
Lattice Relaxation ◽  
Electronic Density ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Coverage Dependence ◽  
Hydrogen Molecules ◽  
Wide Range

ABSTRACTKaolinite can be used for many applications, including the underground storage of gases. Density functional theory was employed to investigate the adsorption of hydrogen molecules on the kaolinite (001) surface. The coverage dependence of the adsorption sites and energetics was studied systematically for a wide range of coverage, Θ (from 1/16 to 1 monolayer). The three-fold hollow site is the most stable, followed by the bridge, top-z and top sites. The adsorption energy of H2 decreased with increasing coverage, thus indicating the lower stability of surface adsorption due to the repulsion of neighbouring H2 molecules. The coverage has obvious effects on hydrogen adsorption. Other properties of the H2/kaolinite (001) system, including the lattice relaxation and changes of electronic density of states, were also studied and are discussed in detail.

Preferred Hydrogen Adsorption Sites in Various MOFs-A Comparative Computational Study

ChemPhysChem ◽  
2009 ◽  
Vol 10 (15) ◽  
pp. 2647-2657 ◽  
Author(s):  
Michael Fischer ◽  
Frank Hoffmann ◽  
Michael Fröba
Keyword(s):  
Hydrogen Adsorption ◽  
Computational Study ◽  
Adsorption Sites

Hydrogen Adsorption in MOF-74 Studied by Inelastic Neutron Scattering

2007 ◽  
Vol 1041 ◽  
Author(s):  
Yun Liu ◽  
Craig M. Brown ◽  
Dan A. Neumann ◽  
Houria Kabbour ◽  
Channing C. Ahn
Keyword(s):  
Neutron Scattering ◽  
Binding Site ◽  
Binding Sites ◽  
Hydrogen Adsorption ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Attractive Potential ◽  
Potential Wells ◽  
Adsorption Sites ◽  
Hydrogen Molecules

AbstractAdsorption of hydrogen and the occupancy of different binding sites as a function of hydrogen loading in MOF-74 are studied using inelastic neutron scattering (INS). Hydrogen molecules are observed to fully occupy the strongest binding site before populating other adsorption sites. The comparison of the INS spectra at 4 K and 60 K indicates that hydrogen adsorbed at the strongest binding site is strongly bound and localized. We also show that when two hydrogen molecules are adsorbed into a single, attractive potential well, the shortest inter-H2 distance is about 3 Å, consistent with our previous observation of inter-H2 distance when adsorbed in two neighboring potential wells.

Ti-coated BC2N nanotubes as hydrogen storage materials

2013 ◽  
Vol 91 (7) ◽  
pp. 598-604 ◽  
Author(s):  
Seifollah Jalili ◽  
Farzad Molani ◽  
Jeremy Schofield
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Molecular Form ◽  
Hydrogen Storage Materials ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Bc2n Nanotubes

Density functional theory (DFT) calculations have been performed to investigate Ti adsorption on BC2N nanotubes and the hydrogen adsorption capacity of Ti-coated structures. Different adsorption sites have been examined for the Ti adatom, and it is found that the most stable structure has a configuration with alternating columns of carbon and boron–nitrogen hexagons. The DFT calculations indicate that an adsorbed Ti atom on a carbon hexagon can bind four hydrogen molecules in molecular form, while Ti atoms on boron–nitride hexagons can adsorb three hydrogen molecules and two hydrogen atoms. Based on the calculations, the gravimetric efficiency corresponding to decoration of 67% of six carbon rings with Ti adatoms is estimated to be 8 wt %. Computation of the charge transfer reveals that the Ti atom on BC2N is in a cationic state. In addition, Ti adsorption has a significant influence on the electronic structure of the nanotubes and allows for the conversion of nanotubes from semiconductors in the pristine state to conductors upon doping. The interactions between the nanotubes, the Ti atom and hydrogen molecules have also been analyzed using Dewar coordination and Kubas interactions.

ENHANCEMENT EFFECT OF LITHIUM-DOPING FUNCTIONALIZATION ON HYDROGEN ADSORPTION IN METAL-ORGANIC FRAMEWORK

2016 ◽  
Vol 24 (05) ◽  
pp. 1750067 ◽  
Author(s):  
LIANGZHI XIA ◽  
QING LIU ◽  
FENGLING WANG ◽  
YUPENG LI
Keyword(s):  
Hydrogen Adsorption ◽  
Metal Organic Framework ◽  
Enhancement Effect ◽  
Li Doping ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Metal Organic ◽  
Gravimetric Adsorption ◽  
Hydrogen Storage Performance ◽  
Grand Canonical

Grand canonical Monte-Carlo simulation was carried out to study the effect of linker functionalization by Li atoms. In this work, two new Li-doping structures, MOF-808-Li and MOF-808-OLi were theoretically constructed by physical modification and chemical modification, respectively. The results show that both these methods can improve the hydrogen storage performance significantly, owing to the Li atoms increasing the interaction energy between the hydrogen molecules and the Li-doped MOF-808. Furthermore, MOF-808-OLi shows higher hydrogen capacity in comparison to the H2 adsorption in the MOF-808-Li, this can be attributed to the new adsorption sites created by oxygen atom. The gravimetric adsorption capacity of MOF-808-OLi can reach 3.17[Formula: see text]wt.% at 77[Formula: see text]K and 1[Formula: see text]bar, which are significantly higher than the hydrogen adsorption in the unmodified MOF-808.

Prediction of hydrogen adsorption in nanoporous materials from the energy distribution of adsorption sites

2019 ◽  
Vol 117 (23-24) ◽  
pp. 3683-3694 ◽  
Author(s):  
Arun Gopalan ◽  
Benjamin J. Bucior ◽  
N. Scott Bobbitt ◽  
Randall Q. Snurr
Keyword(s):  
Energy Distribution ◽  
Hydrogen Adsorption ◽  
Nanoporous Materials ◽  
Adsorption Sites

scholarly journals Adsorption Sites of Hydrogen Atom on Pure and Mg-Doped Multi-Walled Carbon Nanotubes

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
A. A. Al-Ghamdi ◽  
E. Shalaan ◽  
F. S. Al-Hazmi ◽  
Adel S. Faidah ◽  
S. Al-Heniti ◽  
...  
Keyword(s):  
Hydrogen Adsorption ◽  
Md Simulations ◽  
Material System ◽  
Magnesium Atom ◽  
Multiwalled Carbon ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Mg Doped

Hydrogen adsorption sites on pure multiwalled carbon nanotube (MWCNT) and Mg-doped MWCNTs material system have been investigated using molecular dynamics (MD) simulations as well as quantum chemical calculations. Through combining MWCNTs with Mg, the hydrogen adsorption sites energy on this Mg-MWCNTs system is found to be larger than that of the pure MWCNTs. Additionally, it was found that, through Mg-doping, new adsorption sites for hydrogen molecules are created in comparison with undoped nanotubes. It is also found that H atom is preferably adsorbed at every place near magnesium atom.

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