The effect of modification of Zn–Mg(Zr)Si oxide catalysts with rare-earth elements (Y, La, Ce) in the ethanol-to-1,3-butadiene process

This paper presents the results of an investigation of Zn–Mg(Zr)Si nanophase oxide systems modified with rare-earth elements (REE: yttrium, lanthanum, and cerium). The prepared systems are characterized by X-ray diffraction, low-temperature (77 K) nitrogen ad(de)sorption, Raman, UV–Vis diffuse reflectance and FTIR spectroscopy of adsorbed pyridine, and temperature-programmed desorption of NH 3 and CO 2 . The effect of REE modification on the efficiency of the aqueous ethanol-to-1,3-butadiene process over Zn–Mg(Zr)Si oxide catalysts is shown. The rate of 1,3-butadiene formation rises up to four times as a result of the acceleration of the key step of the ethanol-to-1,3-butadiene process, the aldol condensation of acetaldehyde. The cause of this effect is a change in acid–base characteristics of Zn–Mg(Zr)Si oxide systems upon the introduction of REE additives in their composition. The change in acid–base characteristics of the modified Zn–MgSi oxide system is additionally caused by the formation of a nanolayered magnesium silicate hydrate phase.