Paired Pulse Electrocatalytic Conversion of Phenol for Co-Production of Cyclohexanol and Para-Benzoquinone

Electrochemical upcycling of organic pollutants in wastewater into value-added chemicals presents a dual solution for water treatment and sustainable synthesis, yet achieving high Faradaic and energy efficiencies remains challenging. Here we, for the first time, report the paired electrolysis strategy to produce valuable cyclohexanol and para-benzoquinone (p-BQ) simultaneously from phenol in wastewater. More importantly, to address the dilemma of mismatched operation conditions between cathodic hydrogenation and anodic oxidation, we propose a pulse current strategy with alternating high-/low-current periods, which ensures the reduction kinetics of phenol at the cathode while effectively preventing the over-oxidation of generated p-BQ at the anode. By using tailored PdRu/C and NiRu/C as the cathode and anode, the paired pulse system realizes 84.9% phenol conversion and 83.9% cyclohexanol yield at the cathode, alongside 100% phenol conversion and 68.5% p-BQ yield at the anode, with an exceptional Faradaic efficiency of 114.5% and ultra-low energy consumption of 0.064 kWh mol⁻¹. Carbon emission accounting and techno-economic analysis highlight its environmental benefits and economic feasibility (US$1.36 profit per kg phenol). This work offers a green and efficient route for environmental remediation and resource recovery.