Transformation of bioethanol to 1,3-butadiene and other bulk chemicals over the surface of Mg–Al catalysts

Abstract

The synthesis of bulk chemicals from bioethanol and analysis of the product distribution over Mg–Al catalysts were investigated. Preparation methods of co-precipitation, hydrotalcite-like compounds and impregnation were studied. Catalysts were characterized by X-ray diffraction, nitrogen adsorption–desorption, scanning electron microscopy, transmission electron microscopy, NH₃-temperature-programmed desorption (NH₃-TPD), CO₂-TPD and Fourier-transform infrared spectroscopy of adsorbed pyridines. Different preparation methods had an impact on the surface structure and chemical nature of the catalysts. Ethylene was obtained mainly on sites of strong acids and strong bases. Sites of moderately strong acids and bases were suitable for 1,3-butadiene (BD) formation. To obtain higher BD selectivity, the ratios of MgO and Al₂O₃ must be examined and modifiers used to adjust the acid–base balance must be adopted in Mg–Al catalysts.