Aquivion® PFSA-based spray-freeze dried composite materials with SiO2 and TiO2 as hybrid catalysts for the gas phase dehydration of ethanol to ethylene in mild conditions

Aquivion® PFSA-based spray-freeze dried composite materials with SiO2 and TiO2 as hybrid catalysts for the gas phase dehydration of ethanol to ethylene in mild conditions

Stefania Albonetti, Martina Battisti, Sara Andreaoli, Riccardo Bacile, Claudio Oldani, Simona Ortelli, Anna Luisa Costa, Giuseppe Fornasari

Abstract

The spray-freeze-drying approach was successfully applied for the preparation of Aquivion based composites with high surface area. The encapsulation of different oxides, such as TiO 2 and SiO 2 in the superacid matrix was easily obtained using this technique and compared with catalysts prepared by the impregnation conventional route. SFD approach led to the preparation of porous micro-granules characterised by a high homogeneity in the phase distribution. The prepared materials were active and selective for the gas phase dehydration of ethanol to ethylene in mild conditions. The increase of the accessibility and the stability of active sites improved the activity of the composites and allowed to reduce the amount of the superacid resin. Moreover, the type of encapsulated oxide, TiO 2 or SiO 2 , modified the improved performance of the catalysts , having TiO2 the higher efficiency for ethanol conversion and selectivity in ethylene at very low temperature.

Keywords

heterogeneous acid catalysts, perfluorosulfonic resins, ethanol dehydration, ethylene