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.
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. - In: GREEN CHEMISTRY. - ISSN 1463-9262. - STAMPA. - 18:6(2016), pp. 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.