Electrospray-Based Flow Reaction System for Intensified Transfer Hydrogenation of Acetophenone

A flow reaction system based on electrospray was established to study the phase-transfer hydrogenation of acetophenone. Electrospray was targeted as an energy-efficient option for enhancing liquid–liquid mass transfer. Aqueous solution of sodium formate was continuously sprayed into the organic phase under the influence of an external electric field. An increase of the applied voltage resulted in an increase in conversion and yields. The polarity of applied electric fields was found to show no effect on the reaction performance. The induced electric current in the reaction system due to the increased conductivity of the continuous organic phase correlated to the improved reaction conversion and yields. The conversion in the electrospray system reached 71% in 1 h, showing a significant improvement with much less energy consumption compared to that in a stirred batch system.