1. Redox-mediated decoupled seawater direct splitting for H2 production.
- Author
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Liu, Tao, Lan, Cheng, Tang, Min, Li, Mengxin, Xu, Yitao, Yang, Hangrui, Deng, Qingyue, Jiang, Wenchuan, Zhao, Zhiyu, Wu, Yifan, and Xie, Heping
- Subjects
OXYGEN evolution reactions ,CLEAN energy ,ELECTROLYTIC oxidation ,RENEWABLE energy sources ,SEAWATER - 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
2 evolution reactor is established. Ferricyanide/ferrocyanide ([Fe(CN)6 ]3−/4− ) 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−2 and ~1.57 V at 100 mA cm−2 ) 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. Seawater direct electrolysis using renewable energy provides an appealing pathway to harness abundant oceanic hydrogen resources. Here, authors report a redox-mediated decoupled seawater direct electrolysis strategy to suppress the chlorine electro-oxidation side reaction. [ABSTRACT FROM AUTHOR]- Published
- 2024
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