Elucidating electrocatalytic mechanism for large-scale cycloalkanol oxidation integrated with hydrogen evolution

Replacing oxygen evolution reaction with the more thermodynamically favorable organics oxidation reaction is crucial to reduce the required voltage of overall water splitting. Herein, Co2(OH)3Cl/FeOOH nanosheets are served as both cathode and anode for the concurrent high purity hydrogen generation and high value-added cyclohexanone productions. Thanks to the wondrous synergistic effect between Co2(OH)3Cl and FeOOH, for Co2(OH)3Cl acted as the optimal catalytic sites for cyclohexanol oxidization and FeOOH accelerated the reaction rates by reducing the charge transfer resistance, the two-electrode configuration only required a voltage as low as 1.46 V at 10 mA·cm−2 for cathode H2 and anode cyclohexanone. Moreover, by further scaling up the configuration into the 10*10 cm2 anion membrane electrode assembly reactor, a cyclohexanone production rate of 3.44 g/h and the electricity saved about 0.24 kWh/ m3 (H2) were achieved. In addition, the reaction pathways, the C–H bond cleaves first, and then the intermediate carbon free radical is dehydrogenated to generate cyclohexanone on CoII/CoIII redox, was elucidated elaborately. This work offers an approach to actuate effective transformation of organics with high selectivity and industrial practicability under ambient conditions powered by renewable energy.