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 O2 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.

Details

Title
Redox-mediated decoupled seawater direct splitting for H2 production
Author
Liu, Tao 1   VIAFID ORCID Logo  ; Lan, Cheng 2   VIAFID ORCID Logo  ; Tang, Min 3 ; Li, Mengxin 4 ; Xu, Yitao 3 ; Yang, Hangrui 5 ; Deng, Qingyue 3 ; Jiang, Wenchuan 2   VIAFID ORCID Logo  ; Zhao, Zhiyu 2 ; Wu, Yifan 2   VIAFID ORCID Logo  ; Xie, Heping 6   VIAFID ORCID Logo 

1  Sichuan University & Shenzhen University, State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581); Sichuan University, Institute of New Energy and Low-Carbon Technology, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581); Shenzhen University, Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization, Institute of Deep Earth Sciences and Green Energy, Shenzhen, China (GRID:grid.263488.3) (ISNI:0000 0001 0472 9649); Shenzhen University, Shenzhen Key Laboratory of Deep Engineering Science and Green Energy, Institute of Deep Earth Sciences and Green Energy, Shenzhen, China (GRID:grid.263488.3) (ISNI:0000 0001 0472 9649) 
2  Sichuan University & Shenzhen University, State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581); Sichuan University, Institute of New Energy and Low-Carbon Technology, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581); Shenzhen University, Shenzhen Key Laboratory of Deep Engineering Science and Green Energy, Institute of Deep Earth Sciences and Green Energy, Shenzhen, China (GRID:grid.263488.3) (ISNI:0000 0001 0472 9649) 
3  Sichuan University-Pittsburgh Institute, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581) 
4  Sichuan University, Institute of New Energy and Low-Carbon Technology, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581); Shenzhen University, Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization, Institute of Deep Earth Sciences and Green Energy, Shenzhen, China (GRID:grid.263488.3) (ISNI:0000 0001 0472 9649) 
5  Sichuan University, School of Chemical Engineering, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581) 
6  Sichuan University & Shenzhen University, State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581); Sichuan University, Institute of New Energy and Low-Carbon Technology, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581); Shenzhen University, Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization, Institute of Deep Earth Sciences and Green Energy, Shenzhen, China (GRID:grid.263488.3) (ISNI:0000 0001 0472 9649); Shenzhen University, Shenzhen Key Laboratory of Deep Engineering Science and Green Energy, Institute of Deep Earth Sciences and Green Energy, Shenzhen, China (GRID:grid.263488.3) (ISNI:0000 0001 0472 9649); Sichuan University, College of Water Resource & Hydropower, Chengdu, China (GRID:grid.13291.38) (ISNI:0000 0001 0807 1581) 
Pages
8874
Publication year
2024
Publication date
2024
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41467-024-53335-w
ProQuest document ID
3116458702
Copyright
© The Author(s) 2024. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.