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In the present work, MgÀAlÀZnÀFe layered double hydroxides (LDH) were prepared by coprecipitation reaction with hydrothermal treatment. Their corresponding calcinated products (mixed oxides) were used as catalyst for ethylbenzene dehydrogenation to styrene. The characterization of precursors and the mixed oxides was carried out by X-ray diffraction, XPS, TGA-DSC, UVÀvis-DRS, specific surface area, and magnetic properties. The Fe 3þ species were detected by XPS; they exist in two chemical states related to oxides and spinel environment. Zn is found in two possible contributions, such as ZnO or spinel. XRD data indicate that the hydrotalcite phase exists in all precursor samples, except for the sample without magnesium (HT 100 ). In the mixed oxides the ZnO phase increases with the rise of the Zn content. Oxides show a decrease of surface areas with the increase of the Zn content. Ethylbenzene dehydrogenation was carried out with the mixed oxides synthesized. The HT 25 sample with Zn/(Zn þ Fe) = 0.25 molar ratio shows a 31.5% conversion and selectivity to styrene superior to 87%, which is directly related to the quantity of oxide, spinel phase and magnesium, as well as the high surface area and the magnetic response obtained.

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The massive use of petroleum and its possible exhaustion are driving the current research trend to study alternative raw materials from biomass for organic reactions. In this context, the present article presents a study of the catalytic esterification of levulinic acid, a platform molecule, with ethanol. Metal-organic framework (MOF) type compounds UiO-66-NH2 have been synthesized. Zirconium was incorporated, using zirconium chloride as a metal precursor, together with 2-aminoterephthalic acid as an organic binding agent. An alternative route of synthesis was proposed using more favorable conditions from an economic and environmental point of view, replacing dimethylformamide by 50 and 75% acetone as substitute solvent. The physicochemical properties of the materials were evaluated by X-ray diffraction (XRD), Infrared Spectrometry with Fourier Transform (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), microwave plasma atomic emission spectroscopy (MP-AES) and N2 adsorption to understand their morphology, crystalline, chemical and pore structure. The progress of the reaction was followed by gas chromatography and mass spectroscopy. The catalytic activity result of MOF25% in autoclave reactor, showed 100% of selectivity to ethyl levulinate and a turnover number (TON) of 66.18 moles of product/moles of Zr. This good catalytic performance obtained by partial solvent replacement in the synthetic material provides a more economical and eco-friendly process for ethyl levulinate generation.