Surface-Active Catalysts for Interfacial Gas–Liquid–Solid Reactions

Abstract

Multiphase reactions combining gas and liquid phases and a solid catalyst are widespread in the chemical industry. The reactions are typically affected by the low gas solubility in liquids and poor mass transfer from the gas phase to the liquid, especially for fast reactions, leading to much lower activity than the intrinsic catalytic activity. In practice, high pressure, temperature, and cosolvents are required to increase the gas solubility and boost the reaction rate. Gas–liquid–solid (G-L-S) microreactors based on particle-stabilized (Pickering) foams rather than conventional surfactant-stabilized foams can increase the contact between the gas and liquid phases, together with surface-active catalytic particles, and dramatically accelerate G-L-S reactions. Unlike surfactants, surface-active catalytic particles can be recycled and reused and reduce coalescence, Ostwald ripening, and aggregation by adsorbing selectively at the G-L interface, promoting stability.