The balance of electric field and interfacial catalysis in promoting water dissociation in bipolar membranes

摘要: The lamination of a cation exchange layer (CEL) and an anion (AEL) to form hybrid bipolar membrane (BPM) can have several unique advantages over conventional monopolar ion membranes in (photo-)electrolysis. Upon application reverse bias, the ordinarily slow water dissociation reaction at AEL/CEL junction BPM is dramatically accelerated by large electric field interface presence catalyst junction. Using electrochemical impedance spectroscopy (EIS), we found counterbalanced role accelerating BPM. Experimental BPMs were prepared from crosslinked AEL Nafion CEL, with graphite oxide (GO) deposited using layer-by-layer (LBL) assembly. interfacial smaller fields compared samples no added catalyst. A comprehensive numerical simulation model showed that damping result higher product (H+/OH−) flux, which neutralizes net charge density CEL AEL. This conclusion further substantiated EIS studies high-performance 3D shows low due facile catalytic generation transport H+ OH−. Numerical modeling these effects provides prescription for designing function lower overpotential. potential drop across synthetic was than commercial more 200 mV >100 mA cm−2 bias current density, two having similar long-term stability.