To achieve safe recovery of H₂ gas during water purification using the electrochemical oxidation (EO) process, we decoupled anodic oxidation and cathodic H₂ evolution driven by reactions on closed bipolar electrodes with two poles in two separated solutions containing [Fe(CN)₆]^4-/3- as a soluble electron mediator. With increased current density of 1-16 mA cm^-2, the anodic removal of phenol pollutant was increased from 37.28% (k=0.0039 min^-1) to 96.44% (k=0.028 min^-1), and meanwhile the cathodic H₂ production was increased from 6.35 mL to 137.51 mL within 120-min electrolysis. The H₂ gas was recovered at a coulombic efficiency (CE) of 71.77-99.88% and energy efficiency (EE) of 10.48-22.74%. The cyclic voltammetry (CV) scan results confirmed the capability of aqueous [Fe(CN)₆]^4-/3- redox couple to mediate electrolysis in the EO/C-BPE cell. This study provides a proof-in-concept demonstration of a spatially decoupled anodic oxidation and cathodic H₂ production, making electrochemical water purification more secure, more economical and more sustainable.

为了实现H的安全恢复_2种使用电化学氧化水净化过程中气体（EO）过程中，我们去耦阳极氧化和阴极ħ ₂进化由反应上封闭的双极电极具有两个极中两个被驱动的分离出的含的[Fe（CN）的解决方案₆ ] ^{4- / 3-}作为可溶性电子介体。随着电流密度的增加（1-16 mA cm ^-2），苯酚污染物的阳极去除率从37.28％（k = 0.0039 min ^-1）增加到96.44％（k = 0.028 min ^-1），同时阴极H ₂在120分钟的电解时间内，产量从6.35 mL增加到137.51 mL。以71.77-99.88％的库仑效率（CE）和10.48-22.74％的能量效率（EE）回收H ₂气体。循环伏安法（CV）扫描结果证实了[Fe（CN）₆ ] ^{4- / 3-}氧化还原水溶液介导EO / C-BPE电池中电解的能力。这项研究提供了在空间上解耦的阳极氧化和阴极H ₂产生的概念验证，从而使电化学水净化更安全，更经济，更可持续。