*2.6.1.2. Systems thermogravimetry lamellar characterization*

Figure 10 shows samples of thermograms of the corresponding phase L1 as well as profiles of conventional or normal activation energy obtained from synthesized, likewise in gray color. The samples shown are the activation energy profiles obtained after dehydration of the corresponding material in its phase L0. The difference between the profiles of activation energy is due to local variations of the chemical potential of water or kinetic disabilities in reversible reactions caused by the removal of part of the water when the temperature is increased in the same way.

Thermal analysis is performed in four aspects: (i) analyze how to change kinetic parameters in a same phase for different metals of assembly, (ii) observe the influence of kinetic parameters over the same metal assembly on three different stages, (iii) analyze L0 to L1 phase change during the process of dehydration, and (iv) vary kinetic parameters as the partial pressure of water in the system is changed. All materials are needed to monitor the process of dehydration with the help of XRD to observe when there is a change in the structure or collapse once the

In order to understand how water molecules are found in the material and thus to make one website speedily of the kinetic parameters during the process of dehydration, two-dimensional networks of water molecules are presented in three different phases (see Figure 9). Note that the water molecules are organized along two-dimensional planes alternating the position between coordinated octahedral (defined by the position of the metal) sites and the position

**Figure 9.** Two-dimensional representation of the network of water molecules in the different lamellar systems for (a)

Figure 10 shows samples of thermograms of the corresponding phase L1 as well as profiles of conventional or normal activation energy obtained from synthesized, likewise in gray color. The samples shown are the activation energy profiles obtained after dehydration of the

L1 phase, (b) K phase, and (c) L0 phase. Each red sphere is a water molecule without the hydrogen atoms.

*2.6.1.2. Systems thermogravimetry lamellar characterization*

*2.6.1.1. Two-dimensional network of water molecules in the three phases interpretation*

material molecules are removed totally or partially.

56 Advances in Petrochemicals

in the existing cavities between polyhedral.

**Figure 10.** Thermogravimetric and activation energy profiles for K phase with the different transition metals: (a) Nickel (Ni2+), (b) cobalt (Co2+), and (c) manganese (Mn2+). Blue points are activation energy profiles.

In Figures 11a and 11b, it can be observed that the morphology of the system once it passes from step L0 to L1 phase is maintained when three molecules of water are removed, showing only a change in the volume of material during the transition. The system presents forms as flakes, which is a laminar structure manifestation in these materials that crystallize. The L1 phase synthesized presents particle sizes smaller than that obtained by the transition.

In the characterization by SEM, the only sample that differs from the others is the phase L0 with nickel and external metal because this has very organized small flakes. Figure 12 shows that this structural arrangement explains why this material has low activation energies for the L1 phase derived from the corresponding L0.

**Figure 11.** SEM micrographs of (a) as-prepared L0 phase, (b) L1 derived from L0 after heating, and (c) as-prepared L1 phase. The insets show a magnification of a selected area.

**Figure 12.** SEM micrograph of the as-prepared Ni-L0 phase.
