Foams Stabilized by Aquivion^TM PFSA: Application to Interfacial Catalysis for Cascade Reactions

Abstract Foams are attractive platforms for engineering gas–liquid–solid catalytic microreactors with enhanced triphasic contact. In this study, the foaming properties of surface‐active Aquivion^TM perfluorosulfonic acid resin (Aquivion^TM PFSA) are unraveled. Stable aqueous and non‐aqueous foams are prepared driven by hydrogen bond interactions between Aquivion^TM PFSA and protic solvents (e.g., benzyl alcohol, aniline, water). In light of these unique properties, a catalytic foam system for one‐pot cascade deacetalization–hydrogenation reactions is designed. As proof of concept, benzaldehyde dimethyl acetal is converted into benzyl alcohol with 84% overall yield at room temperature in a foam system in the presence of Aquivion^TM PFSA and Pd/SiO₂ catalysts, whereas the yield is halved in a non‐foam system. The enhanced reaction efficiency is attributed to a marked increase in interfacial area of the foam system and preferential location of catalytic acid centers at the gas–liquid interface.