Managing electrolyte flow boosts the efficiency of continuous oxime electrosynthesis to over 95%

Electrified chemosynthesis shows great promise for sustainable chemical manufacturing. However, the reaction efficiency in continuous flow electrochemistry is currently unsatisfactory due to restricted mass transport at the two-phase boundary. Here we present an effective flow management strategy involving electrolyzer structural optimization to intensify the localized electrochemical process. We demonstrate this approach using the electrosynthesis of cyclohexanone oxime from cyclohexanone and nitrite as a representative example. The cathodic counterpart is regulated by a flow-through channel architecture that drives the significant electrolyte convection throughout the porous electrode matrix and minimizes the hydrodynamic diffusion distance, giving the catalyst full accessibility to the feedstock. Using an optimal cobalt single-atom catalyst, we demonstrate the oxime electrosynthesis with a Faradaic efficiency of over 95%, regardless of the operating conditions. Furthermore, we achieve a high single-pass conversion efficiency of up to 95% by balancing the supply of feedstocks between cyclohexanone and in situ generated hydroxylamine through subtle control of the electrolyte flow rate. This continuous-flow electrosynthesis process demonstrates long-term stability, operating for up to 110 hours without the loss of activity, which highlights its great potential for practical implementation. The efficient mass transport is the key factor to advancing the flow-electrocatalytic chemosynthesis. Here, the authors design a flow-through architecture in flow electrolyzer, reinforcing mass transport in the electrolyte to achieve the high efficiency of continuous oxime electrosynthesis.