Metal-organic frameworks (MOFs) based on Calcium-terephthalate(Ca-MOFs) were synthesized by the sonochemical method and applied to remove methylene blue (MB) from an aqueous solution via adsorption. The samples were prepared and characterized by X-ray Powder Diffraction (PXRD), Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Thermal Analysis (TGA-DTA), and Scanning Electron Microscopy (SEM). The studied of the effect of the synthesis temperature on the crystallization of MOFs indicated two different crystal structures were identified, Ca(BDC) and Ca(BDC)(H2O)3. Observed that samples with a higher proportion of the Ca(BDC) phase showed greater dye adsorption capacity. The experimental data fit the pseudo-second-order kinetic model. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms, and the isotherm constants were also determined. The adsorption equilibrium data preferably fit the Freundlich model. The samples were applied to methylene blue adsorption at pH 5.6, with maximum adsorption of 60.241 μmol.g-1 and high reuse efficiency, reaching 97% of the initial adsorption capacity in the second reuse cycle.

The control of the size and morphology of Metal-Organic Frameworks is a challenge that must be overcome to ensure the use of these materials in advanced applications. Mixed Lanthanide-Organic Frameworks (MLOFs) were synthesized via solvo(hydro)thermal method and then characterized by PXRD, IR, TG/DTA, SEM and PL spectroscopy. The effect of the modulator (acetic acid) on the morphological characteristics of the obtained powders was investigated. Trivalent terbium ions were successfully incorporated into La-framework conferring green luminescence to the prepared samples. It was observed that a gradual increase in acetic acid concentration led to the morphology change from micro-rods to flower-like small particle agglomerates. Moreover, a higher concentration of the acetic acid prevented the crystallization of secondary phases.

Nickel-based catalyst precursor for dry reforming of methane was successfully prepared by a self-combustion method. Three different amino acids: urea, glycine and citric acid were tested as fuels in the redox reaction with metal nitrates. For each fuel, a thermodynamic modeling of the combustion reaction was performed. The samples were characterized by X-ray diffraction (XRD), Thermogravimetric analysis (TG), Scanning electron microscopy (SEM), Attenuated total reflectance – Fourier transform infrared (ATR-FTIR) spectroscopy and Temperature-programmed reduction (TPR). XRD data confirmed the presence of several crystalline phases in the as-prepared powders. The sample prepared with citric acid showed very low crystallinity when compared to the other samples. It was found that the heat release rate of the self-combustion is the determinant factor of the crystallization, and it is fuel dependent. SEM results suggest that the distribution and average particle size of as-prepared powders can be controlled by the appropriate selection of the fuel. Further calcination of these samples at 800 °C/4h led to the crystallization of perovskite-type structure LaNiO3. Nanostructured Ni0/La2O3 obtained after reduction of LaNiO3 precursor showed high catalytic activity in dry reforming of methane.