New insights into the transformation of ethanol to butadiene over MgO-SiO2 catalysts, prepared by means of the sol-gel technique, have been gained via characterization, catalytic tests, and in situ infrared diffuse reflectance spectroscopy. Catalysts with low Si-content, i.e., with a Mg/Si atomic ratio in the range between 9 and 15, gave superior butadiene yields, because of the proper combination of strong basic sites, required for ethanol activation, and a moderate number of medium-strength acid sites, needed for the dehydration of intermediately formed alkenols to butadiene. A model of the medium-strength, Lewis-type acid sites, consisting of Mg2+ cations with neighbouring Si4+ atoms, has been proposed; these sites are converted into Bronsted sites in the presence of water, a co-product of the multistep transformation of ethanol into C4 molecules.
Velasquez Ochoa, J., Bandinelli, C., Vozniuk, O., Chieregato, A., Malmusi, A., Recchi, C., et al. (2016). An analysis of the chemical, physical and reactivity features of MgO-SiO2 catalysts for butadiene synthesis with the Lebedev process. GREEN CHEMISTRY, 18(6), 1653-1663 [10.1039/c5gc02194d].
An analysis of the chemical, physical and reactivity features of MgO-SiO2 catalysts for butadiene synthesis with the Lebedev process
VELASQUEZ OCHOA, JULIANA;BANDINELLI, CLAUDIA;VOZNIUK, OLENA;CHIEREGATO, ALESSANDRO;MALMUSI, ANDREA;RECCHI, CARLO;CAVANI, FABRIZIO
2016
Abstract
New insights into the transformation of ethanol to butadiene over MgO-SiO2 catalysts, prepared by means of the sol-gel technique, have been gained via characterization, catalytic tests, and in situ infrared diffuse reflectance spectroscopy. Catalysts with low Si-content, i.e., with a Mg/Si atomic ratio in the range between 9 and 15, gave superior butadiene yields, because of the proper combination of strong basic sites, required for ethanol activation, and a moderate number of medium-strength acid sites, needed for the dehydration of intermediately formed alkenols to butadiene. A model of the medium-strength, Lewis-type acid sites, consisting of Mg2+ cations with neighbouring Si4+ atoms, has been proposed; these sites are converted into Bronsted sites in the presence of water, a co-product of the multistep transformation of ethanol into C4 molecules.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
