374
W. Piskorz and F. Zasada
Hydrocarbon Transformation
The hydrocarbon transformation on zeolites was studied computationally for, e.g.
process of ethyne cyclotrimerisation ([294], geometry optimisation and vibrational
analysis with B3LYP functional; simulation of
13 C NMR spectra by B3LYP functional, GIAO, TZVP basis set with ECP). The article of Archipov et al. [295] aims
at the understanding of benzene sorption in CuHY zeolite as a key step in the oxidation of benzene to phenol, using the QM-Pot approach. They conclude that benzene
molecule η
2 -coordinated to copper; after preferential adsorption of Cu to SIII the
coordination to framework oxygens is reduced, although the differentiation between
two adsorption sites, SII and SIII, is difficult based on the IR spectrum. The π -
backdonation from the Cu
+ 3d is more dominating than p-π donation from the
benzene molecule and the oxidation state of copper changes from Cu(II) to Cu(I).
Benzene adsorbs both at Brønsted sites and at Cu centres.
Sorption/Diffusion
Besides the reactivity, the theory and modelling of diffusion in zeolites have gained
sound attention in literature [296–300]. Such properties, either static or timedependent, require an enormous number of the energy evaluations so, as such,
need the very fast methods, typically the classical force field. The simulations help
resolving non-trivial phenomena like non-Langmuir adsorption isotherms, adsorption/desorption hysteresis loops, or faster diffusivity of certain substituted hydrocarbons [298].
3.1.5 Spinels of d-Electron Metals
Spinel oxides belong to scientifically and technologically most attractive oxides with
remarkable record of widespread applications in heterogeneous catalysis [301–303],
energy storage and conversion [304, 305] or sensor devices [306, 307]. In particular,
cobalt spinel oxides derivatives exhibit high activity in low-temperature decomposition of nitrous oxide [308–311], and CoNi 2 O 4 was reported to be highly active
in CH 4 combustion. Mixed Co–Fe–Al spinels, with optical band gaps between 1.6
and 2.0 eV, generate strong p-type photocurrent for photoelectrochemical splitting
of water, whereas ZnCo 2 O 4 [312] or CoMn 2 O 4 [313] has a good cycling capacity in
the Li
+ charge–discharge processes.
Structure and Morphology
Spinels form a wide family of oxides which crystallise in the cubic crystal system
of Fd3m (or F ¯
43m [314]) space group and are characterised by the general AB 2 O 4
formula. The oxygen anions form the face-centred cubic lattice, where the tetrahedral
W. Piskorz and F. Zasada
Hydrocarbon Transformation
The hydrocarbon transformation on zeolites was studied computationally for, e.g.
process of ethyne cyclotrimerisation ([294], geometry optimisation and vibrational
analysis with B3LYP functional; simulation of
13 C NMR spectra by B3LYP functional, GIAO, TZVP basis set with ECP). The article of Archipov et al. [295] aims
at the understanding of benzene sorption in CuHY zeolite as a key step in the oxidation of benzene to phenol, using the QM-Pot approach. They conclude that benzene
molecule η
2 -coordinated to copper; after preferential adsorption of Cu to SIII the
coordination to framework oxygens is reduced, although the differentiation between
two adsorption sites, SII and SIII, is difficult based on the IR spectrum. The π -
backdonation from the Cu
+ 3d is more dominating than p-π donation from the
benzene molecule and the oxidation state of copper changes from Cu(II) to Cu(I).
Benzene adsorbs both at Brønsted sites and at Cu centres.
Sorption/Diffusion
Besides the reactivity, the theory and modelling of diffusion in zeolites have gained
sound attention in literature [296–300]. Such properties, either static or timedependent, require an enormous number of the energy evaluations so, as such,
need the very fast methods, typically the classical force field. The simulations help
resolving non-trivial phenomena like non-Langmuir adsorption isotherms, adsorption/desorption hysteresis loops, or faster diffusivity of certain substituted hydrocarbons [298].
3.1.5 Spinels of d-Electron Metals
Spinel oxides belong to scientifically and technologically most attractive oxides with
remarkable record of widespread applications in heterogeneous catalysis [301–303],
energy storage and conversion [304, 305] or sensor devices [306, 307]. In particular,
cobalt spinel oxides derivatives exhibit high activity in low-temperature decomposition of nitrous oxide [308–311], and CoNi 2 O 4 was reported to be highly active
in CH 4 combustion. Mixed Co–Fe–Al spinels, with optical band gaps between 1.6
and 2.0 eV, generate strong p-type photocurrent for photoelectrochemical splitting
of water, whereas ZnCo 2 O 4 [312] or CoMn 2 O 4 [313] has a good cycling capacity in
the Li
+ charge–discharge processes.
Structure and Morphology
Spinels form a wide family of oxides which crystallise in the cubic crystal system
of Fd3m (or F ¯
43m [314]) space group and are characterised by the general AB 2 O 4
formula. The oxygen anions form the face-centred cubic lattice, where the tetrahedral