Redox-mediated Decoupled Seawater Direct Splitting for H Production

Overview

Journal Nat Commun

Specialty Biology

Date 2024 Oct 14

PMID 39402055

Authors

Tao Liu

Cheng Lan

Min Tang

Mengxin Li

Yitao Xu

Hangrui Yang

Qingyue Deng

Wenchuan Jiang

Zhiyu Zhao

Yifan Wu

Heping Xie

Affiliations

Soon will be listed here.

Abstract

Seawater direct electrolysis (SDE) using renewable energy provides a sustainable pathway to harness abundant oceanic hydrogen resources. However, the side-reaction of the chlorine electro-oxidation reaction (ClOR) severely decreased direct electrolysis efficiency of seawater and gradually corrodes the anode. In this study, a redox-mediated strategy is introduced to suppress the ClOR, and a decoupled seawater direct electrolysis (DSDE) system incorporating a separate O evolution reactor is established. Ferricyanide/ferrocyanide ([Fe(CN)]) serves as an electron-mediator between the cell and the reactor, thereby enabling a more dynamically favorable half-reaction to supplant the traditional oxygen evolution reaction (OER). This alteration involves a straightforward, single-electron-transfer anodic reaction without gas precipitation and effectively eliminates the generation of chlorine-containing byproducts. By operating at low voltages (~1.37 V at 10 mA cm and ~1.57 V at 100 mA cm) and maintaining stability even in a Cl-saturated seawater electrolyte, this system has the potential of undergoing decoupled seawater electrolysis with zero chlorine emissions. Further improvements in the high-performance redox-mediators and catalysts can provide enhanced cost-effectiveness and sustainability of the DSDE system.

Citing Articles

Seawater Membrane Distillation Coupled with Alkaline Water Electrolysis for Hydrogen Production: Parameter Influence and Techno-Economic Analysis.

Xu X, Zhao Z, Song C, Xu L, Zhang W Membranes (Basel). 2025; 15(2).

PMID: 39997686 PMC: 11857186. DOI: 10.3390/membranes15020060.

Comprehensive Chlorine Suppression: Advances in Materials and System Technologies for Direct Seawater Electrolysis.

Zhao C, Ding Z, Zhang K, Du Z, Fang H, Chen L Nanomicro Lett. 2025; 17(1):113.

PMID: 39841341 PMC: 11754585. DOI: 10.1007/s40820-025-01653-z.

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