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A sodium-ion-conducted asymmetric electrolyzer to lower the operation voltage for direct seawater electrolysis.
- Source :
- Nature Communications; 7/4/2023, Vol. 14 Issue 1, p1-11, 11p
- Publication Year :
- 2023
-
Abstract
- Hydrogen produced from neutral seawater electrolysis faces many challenges including high energy consumption, the corrosion/side reactions caused by Cl<superscript>-</superscript>, and the blockage of active sites by Ca<superscript>2+</superscript>/Mg<superscript>2+</superscript> precipitates. Herein, we design a pH-asymmetric electrolyzer with a Na<superscript>+</superscript> exchange membrane for direct seawater electrolysis, which can simultaneously prevent Cl<superscript>-</superscript> corrosion and Ca<superscript>2+</superscript>/Mg<superscript>2+</superscript> precipitation and harvest the chemical potentials between the different electrolytes to reduce the required voltage. In-situ Raman spectroscopy and density functional theory calculations reveal that water dissociation can be promoted with a catalyst based on atomically dispersed Pt anchored to Ni-Fe-P nanowires with a reduced energy barrier (by 0.26 eV), thus accelerating the hydrogen evolution kinetics in seawater. Consequently, the asymmetric electrolyzer exhibits current densities of 10 mA cm<superscript>−2</superscript> and 100 mA cm<superscript>−2</superscript> at voltages of 1.31 V and 1.46 V, respectively. It can also reach 400 mA cm<superscript>−2</superscript> at a low voltage of 1.66 V at 80 °C, corresponding to the electricity cost of US$1.36 per kg of H<subscript>2</subscript> ($0.031/kW h for the electricity bill), lower than the United States Department of Energy 2025 target (US$1.4 per kg of H<subscript>2</subscript>). Hydrogen produced directly from neutral seawater is promising but challenging due to seawater's complex composition. Here, the authors report a Na<superscript>+</superscript>-conducted pH-asymmetric electrolyzer that can directly split seawater into hydrogen with low electricity cost and nearly zero chloride interference. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20411723
- Volume :
- 14
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Nature Communications
- Publication Type :
- Academic Journal
- Accession number :
- 164706817
- Full Text :
- https://doi.org/10.1038/s41467-023-39681-1