Adsorption ability of pristine C24N24 nanocage promising as high hydrogen storage material : A DFT-D3 investigation

Adsorption of eight numbers of H2, (H2)n where n = 1, 2, 4, 6, 8, 12, 18, 24, adsorbed on the C24N24 nanocage (CNNC) surface was investigated using three different DFT methods. Adsorption energies of various numbers of H2 adsorbed on the CNNC surface were obtained. Adsorption strength of the CNNC was found depending on the adsorbed H2 numbers and is in order: the H2 numbers of (H2) > (H2)2 > (H2)4 > (H2)6 > (H2)8 > (H2)12 > (H2)18 > (H2)24. The most stable adsorption configuration of (H2)12/CNNC, all adsorbed H2 molecules formed as the full monolayer (ML) coverage, are dissociative chemisorption. The bilayer of (H2)24/CNNC was found that the first and second layers are composed of 12H2 as dissociative chemisorption and 12H2 as physisorption, respectively. The high hydrogen storage capacity of the CNNC formed as (H2)24/CNNC, around 7.75 wt% was found.</p

Hydrogen adsorption on Pt-decorated closed-end armchair (3,3), (4,4) and (5,5) single-walled carbon nanotubes

<p>Structures of small lengths of capped (3,3), (4,4) and (5,5) single-walled carbon nanotubes (SWCNTs) and their structures decorated by Pt atom and Pt<i>_n</i> clusters (<i>n</i> = 2–4) were obtained using density functional theory calculations. Binding abilities of Pt atom and Pt<i>_n</i> clusters on the outer surface of SWCNTs at various adsorption sites were explored. Adsorptions of H₂ onto Pt atom of the Pt-decorated (3,3), (4,4) and (5,5) SWCNTs were studied and their adsorption energies are reported. The thermodynamic properties and equilibrium constants for H₂ adsorptions on the Pt₄-decorated (3,3), (4,4) and (5,5) SWCNTs were obtained. The adsorption of H₂ on the Pt atom of the Pt₄/(3,3) SWCNT was found to be the most preferred reaction of which enthalpy and free energy changes at room temperature are −46.61 and −23.99 kcal/mol, respectively.</p

Hydrogen molecule adsorption on the MoSe2 and selected-elements (Ru, Os, Rh, Ir, N and P)-doped MoSe2 monolayers as hydrogen storage materials

Adsorption of hydrogen molecules onto the pristine MoSe2 monolayer and N-, P-, Ru-, Rh-, Os- and Ir-doped MoSe2 monolayer surfaces was investigated using periodic DFT method. Adsorption abilities of the pristine and MoSe2 doping derivatives on hydrogen molecule adsorptions are in order: Os–MoSe2 (ΔEads = −2.19 eV) > Ru–MoSe2 (ΔEads = −1.54 eV) > Ir–MoSe2 (ΔEads = −1.08 eV) > Rh–MoSe2 (ΔEads = −0.63 eV) > N–MoSe2 (ΔEads = −0.22 eV) > P–MoSe2 (ΔEads = −0.15 eV) > pristine MoSe2 (ΔEads = −0.06 eV). The adsorption energy of hydrogen onto the Os–MoSe2 surface, which is the most active derivative, stronger than the second most active, the Ru–MoSe2 by 0.65 eV (42%) was found. Nevertheless, all the MoSe2 doping derivatives utilized as hydrogen storage for energy storage purposes were suggested.</p

Selective Oxidation of 25,27-Bis-

Reaction of 25,27-bis-(3-formylphenoxyethoxy)-p-tert-butylcalix[4]arene (1) with 20% mole of KCN in ethanol and i-propanol yielded monoethylester (2) (50%) and monoisopropylester (3) (15%)