Electrochemical Conversion of Lauric Acid through Kolbe Electrolysis for the Synthesis of n-Docosane

Lauric acid (n-dodecanoic acid), a saturated compound derived from animal fats and vegetable oils, can be used as a feedstock for lubricant production. In this work, the production of n-docosane from lauric acid via Kolbe electrolysis was studied using two commercially available electrodes in order to optimize the procedure and also to assess the performance of such electrodes for the production of n-docosane. The optimization study was performed using a compact ElectraSyn 2.0 setup which is commercially available and easy to use. The utilization of the equipment with a regulated power supply, electrodes and other components makes the procedure easily repeatable. The effect of essential parameters influencing the yield of n-docosane was pinpointed in relation to the performance of two different commercial electrodes (platinum- and gold-coated copper). A green, cost-effective and safe electrochemical approach for the production of n-docosane with 45% product yield was obtained using Pt-coated copper electrodes. However, electrode damage and consequent declining performance were also observed during prolonged electrolysis. The confirmation through XRD analysis of the appearance of platinum, gold and copper particles in the solution indicates that such electrodes present a problem of limited durability when used as anodes in synthetic organic reactions.