A kinetic study of hydrogen isotope exchange was carried out in a H2/Pd membrane/organic compound system for a number of compounds in the 0.2–20 kPa H2 pressure range. The results suggest a low specificity of the reaction kinetics for the compounds used. Possible reaction mechanisms are discussed and analyzed.
Faraday induced the mechanochemical reduction of AgCl with Zn, Sn, Fe and Cu in 1820, using trituration in a mortar. This
experiment is revisited, employing a mortar-and-pestle and a ball mill as mechanochemical reactors. The reaction kinetics
depends both on the thermochemical properties and the hardness of the reactants. When using Zn as the reducing agent, Faraday
likely observed a mechanically induced self-sustaining process (MSR), or at least he came very close to doing so.
Studies on the reaction kinetics and mechanism of the synthesis of the Zn2.5VMoO8 compound in the solid state have been carried out in situ in a high-temperature X-ray diffraction attachment. The apparent
activation energy, 21226 kJ mol-1 was calculated by using the diffusion controlled Ginstling-Brounstein model. There was also determined a temperature dependence
of unit cell parameters for Zn3V2O8 and Zn2.5VMoO8.
The reaction kinetics of the mesoporous powder, MCM-TP, anchored with synergistic extractant TOPO-P204, with Pd2+ in spent fuels have been investigated. The results showed that the reaction rate was independent of pellet size, which suggested
that the powder pellet was highly porous and was composed of plate-like “grains”. This analysis was confirmed by observing
the surface and cross section of the pellet with SEM. It provided the physical basis for establishing the liquid-solid reaction
model of mesoporous powders: P-G* model. The calculated curves from the model were in good agreement with the experimental results.
The kinetic and solvent isotope effects during the maleic acid heterogeneous catalytic hydrogenation and deuteration in the
light and heavy water have been studied. Also the effect of the γ and neutron irradiation on the Ni−ZnO catalysts (with various
ratios of components) on the reaction kinetics and mechanism has been measured, as well as the effect of pH on the adsorption
behaviour of maleic acid and the temperature depencence of the reaction rate. Existence of different adsorption centers for
hydrogen and maleic acid could be deduced from these experiments. A reaction mechanism based on the two-dimensional diffusion
of components in the surface is proposed.
For complex decomposition reactions, traditional methods, such as TG and DSC cannot fully resolve all of the steps in the
reaction. Evolved gas analysis (EGA) offers another tool to provide more information about the decomposition mechanism. The
decomposition of sodium bicarbonate was studied by TG, DSC and EGA using a simultaneous thermal analysis unit coupled to a
FTIR. The decomposition of sodium bicarbonate involves two reaction products H2O and CO2, which are not evident from either TG or DSC measurements alone. A comparison of the reaction kinetics from TG, DTG and EGA
data were compared.
The thermal stability of lithium-ion battery cathode could substantially affect the safety of lithium-ion battery. In order
to disclose the decomposition kinetics of charged LiCoO2 used in lithium ion batteries, thermogravimetric analyzer (TG) and C80 microcalorimeter were employed in this study. Four
stages of mass losses were detected by TG and one main exothermic process was detected by C80 microcalorimeter for the charged
LiCoO2. The chemical reaction kinetics is supposed to fit by an Arrhenius law, and then the activation energy is calculated as Ea=148.87 and 88.87 kJ mol−1 based on TG and C80 data, respectively.
A new chemical species of bis(acetonitrile)bis(acetylacetonato)technetium(III), [Tc(acac)2(CH3CN)2]+, has been prepared by the reaction of tris(acetylacetonato)technetium(III) with acetonitrile in the presence of a strong acid, perchloric or hydrochloric acid. The reaction kinetics were followed by observing spectral change of Tc(acac)3 in the UV-visible region. The complex has been characterized by combination of elemental analyses, IR and UV-visible spectrophotometry, ion-exchange chromatography, and paper electrophoresis. Applicability of this substance to synthesize mixed-ligand technetium(III) complexes was discussed based on the solubility of this complex and the ease of substitution of the acetonitrile ligand.