This work describes FT-IR studies results on adsorption of Cu(II) metal cation. Adsorption has been performed on 3A, 4A, 5A, AW-300, ammonium Y zeolite, organophilic, and molecular sieve zeolites using aqueous solution of the metal studied. Changes in intensities and positions of the pseudolattice bands corresponding to ring vibrations have been observed in the measured spectra. These changes are expected particularly in the pseudolattice bands connected with the presence of alumino- and silicooxygen tetrahedral rings in the zeolite structure. Also, Cu(II) adsorbed zeolites were each tested for their ability to catalyse the disproportionation of hydrogen peroxide in the presence of the added base imidazole. The Cu(II) adsorbed zeolites display efficiency in the disproportion reactions of hydrogen peroxide, producing water and dioxygen.
It is argued that mechanical action can induce a unique chemical reaction, if enough mechanical energy is concentrated in the bonds involved in the process to bypass the activation energy. This can happen at crack tips, at the core of dislocations, or at the asperities of colliding or sliding surfaces. A mechanical reaction is always complex, as the macroscopic work is distributed among many possible reaction sites. In comparison, an elementary photochemical reaction is induced by a single photon, while thermochemical reactions rely on the accidental concentration of energy by thermal fluctuations. The paper also compares mechanochemical synthesis in a ball mill with reactions under well-defined loading conditions and mechanochemical experiments carried out on the molecular scale. Closer interaction among those branches of mechanochemistry is urged.
Mechanochemical reactions can provide compounds, phases, and microstructures that are essentially different from the products of ordinary reactions. In this paper, the origin of this uniqueness is discussed in light of the recent advances of the field. It is claimed that the local availability of large batches of energy, well above kT, is the key feature of mechanochemical reactions. As a consequence, reactions that cannot occur thermally become possible, similarly to the reactions induced by the energy of photons in photochemistry. However, the situation is more complex, as macroscopic deformation affects many defect sites simultaneously. The direction of the mechanical load relative to the orientation of a molecule or the crystallographic axes of a solid can be important. Many mechanochemical reactions of organic compounds take place at low milling energy that is not sufficient to break primary bonds, but the gentle mechanical grinding can influence the relative position of macromolecules, leading to the formation of unique cocrystals and compounds. In inorganic systems, unusual products form due to forced mixing and the high defect density generated by intense milling.
Catalytic activity, phase composition, and morphology of binary Ni-Fe metallic systems in CO₂ hydrogenation were investigated. High methane yield was detected in the region of high Ni content, except the sample with 75% of Ni which has shown a sharp drop in activity. By means of scanning electron microscopy-energy dispersive X-ray and X-ray diffraction methods the differences in surface structuring of active (Ni₈₀Fe₂₀) and inactive (Ni₇₅Fe₂₅) catalysts were revealed. High methane yield for the former might be explained by defective porous superficial layer of catalyst grains, whereby for the latter the specific surface is diminished due to sintering.
The properties of Fe-Co catalysts in the reaction of CO₂ hydrogenation were investigated. Samples with high cobalt concentrations have shown higher activity. Morphology of the obtained catalysts was observed by using scanning electron microscopy and the elemental composition of surface of the catalysts was determined by scanning electron microscopy-energy dispersive X-ray method. Energy dispersive X-ray analysis showed that metal distribution is not homogeneous with various metal ratio in selected points of the surface for the Fe-rich less active samples, whereas for the Co-rich samples with higher activity metals are homogeneously distributed, which is possibly connected to the formation of single phase.
A series of 1, 1'-dithiolate ligands were used in the attempted preparation of metal complexes. These bidentate sulphur ligands were subsequently used in aromatic nucleophilic substitution reactions giving rise to several novel organic donor molecules. The electrochemistry data of two of the donors and their subsequent use in the preparation of donor-acceptor compounds is presented. One donor-acceptor compound exhibited high room temperature conductivity (up to 900 S cm^{-1}) and remained metallic down to low temperature. One donor containing two tetrathiafulvalene units was studied by near infrared absorption spectroscopy. An intervalence transition in the monocation form of this donor was observed, indicating that it behaves as a class II mixed valence compound.
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