Development of electrochemical flow reactors as a platform for organic electrosynthesis

Abstract Organic electrosynthesis enables diverse molecular transformations under mild conditions using electrons as traceless reagents, yet its broader applicability has been limited by low productivity, reliance on supporting electrolytes, and energy losses associated with conventional batch reactors. To overcome these challenges, we have redefined them as issues of reaction-field and device design and established electrochemical flow reactors as a versatile platform. Through this approach, we achieved several key advances: (i) realization of supporting-electrolyte-free electrolysis using thin-layer flow cells with micrometer-scale interelectrode gaps; (ii) continuous generation and immediate utilization of unstable reactive intermediates, enabling reactions inaccessible in batch systems; (iii) spatial control of reactivity and selectivity via liquid–liquid parallel laminar flow; (iv) substantial enhancement of productivity using large-surface-area porous electrodes; and (v) extension to solid polymer electrolyte (SPE) systems, providing highly efficient, selective, and energy-saving electrosynthetic processes. Collectively, these innovations demonstrate that organic electrosynthesis can be transformed into a designable reaction platform in which time, space, and interface are precisely controlled. This work highlights the potential of integrating flow and device engineering to advance sustainable and scalable electrosynthetic methodologies.