DFT study of H₂ adsorption at a Cu-SSZ-13 zeolite: a cluster approach

Abstract

In this work the H2 adsorption at a Cu(I)-SSZ-13 exchanged zeolite was theoretically investigated. A systematic cluster approach was used and different density functionals (B3LYP, B3LYP-D3(BJ), M06L, PBE, PBE-D3(BJ) and...

Facet-Induced Strong Metal Chloride−Support Interaction over CuCl2/γ-Al2O3 Catalyst to Enhance Ethylene Oxychlorination Performance

“…This feature is associated with the single scattering contributions arising from O atoms coordinating with Cu. The second lobe in a k space of 8–9 Å –1 , which typically corresponds to the backscattering function of Cu–Cu, was found for 5Cu/Al 2 O 3 -T but not on 5Cu/Al 2 O 3 -P. It indicates that the dispersion of CuCl 2 on 5Cu/Al 2 O 3 -P is much better than that on 5Cu/Al 2 O 3 -T, which can also be confirmed by the XRD patterns of the fresh catalysts (Figure S7). Moreover, the k range of Cu–O of the catalysts was much broader (2.5–6 Å –1 ) compared to the one in Cu–O (3–4 Å –1 ).…”

A Theoretical Investigation of Cu+, Ni2+ and Co2+‐Exchanged Zeolites for Hydrogen Storage

“…Figure 4.a shows that H 2 adsorption on the Cu + that is located in the 6MR of the [Al]−CHA is exothermic by −39 kJ/mol. For this site, binding energies of −15 kJ/mol [47] (cluster model), −20.9 kJ/mol [48] (B3LYP‐D3 functional), −30 kJ/mol [48] (PBE‐D3 method) and −34 kJ/mol [46] (periodic slab) were previously reported in theoretical studies. The adsorption energy of −39 kJ/mol obtained in this work can be considered to be in good agreement with previously reported −34 kJ/mol [46] considering the differences in the level of detail and simulation parameters such as Hubbard U correction or dispersive forces [46] .…”

“…The adsorption energy of −39 kJ/mol obtained in this work can be considered to be in good agreement with previously reported −34 kJ/mol [46] considering the differences in the level of detail and simulation parameters such as Hubbard U correction or dispersive forces [46] . On the other hand, The calculated H 2 adsorption energy of −115 kJ/mol (Figure 4.b) on [Al]−CHA−Cu‐8MR is larger than the previous computational reports of −85 kJ/mol (cluster model, [47] ), −63 kJ/mol (B3LYP‐D3 functional, [48] ), −99 kJ/mol (PBE‐D3 method, [48] ) and −79.8 kJ/mol (periodic BC, [46] ) for the same 8MR site. In order to test the effect of dispersion forces and the delocalization several computations were repeated by fully relaxing the final geometries once more using the Grimme's DFT‐D3 correction and applying Hubbard U correction on the Cu (d) orbitals (6 eV as in Ref.…”

“…On the other hand, computational studies concerning zeolites often uses small cluster models that do not express the effects of high symmetry periodic frameworks such as electrostatic forces. Such studies report H 2 binding energy on Cu + ‐ZSM‐5 [33,35,46] and Cu + ‐SSZ‐13 [32,46–48] . However, available literature does not contain theoretical studies that use periodic frameworks on Ni 2+ and Co 2+ ‐exchanged zeolites to our best knowledge.…”

Understanding the reaction mechanism of the CO2 and cyclohexene oxide copolymerization catalyzed by zinc(II) and magnesium(II) catalysts: a DFT approach

“…Once the TS2 presented such large difference between activation energies for distinct combinations of M 1 -M 2 , it was performed an AIM analysis of TS2 and its previous intermediate (Int3) in order o evaluate the effect of metal changes (M 1 and M 2 ) in the strength of some highlighted chemical bonds (or interactions) beyond its influence on the reactivity of such systems. The quantum theory of atoms in molecules (QTAIM) was developed by Richard Bader [39,40] and has been widely applied in the evaluation and characterization of chemical bonds and noncovalent interactions [41,42]. This theory is based on the topological evaluation of the electronic density ρ(r) to characterize the atoms in the properties of the molecules and their interactions.…”