Investigation of the electrosynthetic pathway of the aldol condensation of acetone

• The potential-controlled aldol condensation of acetone to diacetone alcohol is performed.
• Additional water in the electrolyte has a disadvantageous effect on the reaction.
• The concentration increase of diacetone alcohol describes an exponential curve.

The potential-controlled electrochemical aldol condensation of acetone to diacetone alcohol in a standard batch electrolysis set-up was studied in this work. It is confirmed that the reaction proceeds at the cathode and that, contrary to what is mentioned in earlier literature, water in the electrolyte has a disadvantageous effect on the reaction. Similar to the chemical reaction, the electrochemical reaction reaches a maximum yield when the equilibrium is reached. Separating the anode and cathode prevents cross-over and degradation of products, leading to a higher yield. Starting with pure acetone and support electrolyte, it was possible to obtain a diacetone alcohol concentration of 15 m% after 2 h electrolysis in a divided set-up with a platinum electrode at −2.5 V. The concentration gradient throughout the electrolysis follows an exponential curve up to its equilibrium concentration.