Controlling Selectivity in Electrochemical Conversion of Organic Mixtures through Dynamic Control of Electrode Microenvironments.

Organic electrosynthesis using renewable electricity offers a sustainable approach to chemical manufacturing. Among its promising applications, the selective transformation of complex organic mixtures presents a valuable opportunity to eliminate costly separation processes and directly convert heterogeneous feedstocks to valuable products. However, controlling selectivity in reaction mixtures remains challenging due to competing reaction pathways and varying reactivities among substrates. Here, we demonstrate how selectivity in mixed organic electrosynthesis can be systematically controlled through a balance of reaction kinetics and mass transport limitations. Using acrylonitrile and crotononitrile mixtures as a model substrate mixture, we established quantitative relationships between substrate compositions, current densities, and product distributions that reveal distinct kinetically limited and mass transport-limited reaction regimes that control selectivity. We further demonstrated how pulsed electrolysis can be used to strategically control these reaction regimes to drive selectivity toward specific products. These insights create opportunities for developing adaptive and dynamic chemical manufacturing processes capable of handling complex feedstocks.