Superacid Aquivion® PFSA as an efficient catalyst for the gas phase dehydration of ethanol to ethylene in mild conditions

In this work, Aquivion PFSA resin was shown to be an interesting alternative as a heterogenous catalyst for the continuous gas phase reaction of ethanol dehydration in mild conditions, thanks to its high thermal stability and superacid character. This material was confirmed to have a high thermal stability up to 300 °C, after which the desulphonation process began. Under optimised reaction conditions, the Aquivion catalyst showed a conversion of over 90 % ethanol as well as a selectivity to ethylene. The only detected by-product was diethyl ether, the formation of which was facilitated by low temperature. The dehydration activity was shown to depend on the number of acid sites and material shaping. Fluorescence microscopy, used to study the penetration of different alcohols into the shaped Aquivion, indicated the high polarity of ethanol, enabling the permeation into the pellet structure, thus facilitating the use of the -SO3H that is available on the resin, despite its very low surface area. The catalyst’s durability was proven by a stable operation for 14 h on-stream at 150 °C, without a significant evidence of coke deposition.