Zr doping Co3O4 nanowires mediated adsorption of chloridion for efficient natural seawater electrolysis

Xuexuan Ju; Haoran Guo; Zhiruo Tao; Aihui Niu; Haibing Wei; Jun Song Chen; Xuesong He; Haohong Xian; Xuping Sun; Qingquan Kong; Tingshuai Li

doi:10.1016/j.jcis.2024.12.034

Zr doping Co₃O₄ nanowires mediated adsorption of chloridion for efficient natural seawater electrolysis

J Colloid Interface Sci. 2024 Dec 9;683(Pt 1):189-196. doi: 10.1016/j.jcis.2024.12.034. Online ahead of print.

Authors

Xuexuan Ju¹, Haoran Guo², Zhiruo Tao³, Aihui Niu³, Haibing Wei⁴, Jun Song Chen¹, Xuesong He⁵, Haohong Xian⁵, Xuping Sun⁶, Qingquan Kong⁷, Tingshuai Li⁸

Affiliations

¹ Institute for Advanced Study, Chengdu University, Chengdu 610106, Sichuan, China; School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, Sichuan, China.
² Department of Chemistry, Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Xiangtan University, Xiangtan 411105, Hunan, China.
³ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, Sichuan, China.
⁴ School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, Anhui, China. Electronic address: [email protected].
⁵ Software Department, Chengdu Polytechnic, Chengdu 610095, Sichuan, China.
⁶ College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, Shandong, China.
⁷ Institute for Advanced Study, Chengdu University, Chengdu 610106, Sichuan, China. Electronic address: [email protected].
⁸ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, Sichuan, China. Electronic address: [email protected].

PMID: 39673931
DOI: 10.1016/j.jcis.2024.12.034

Abstract

Natural seawater electrolysis is emerging as a desirable approach for hydrogen production, but it suffers from long-term instability due to severe chloride corrosion. In this study, Zr doped Co₃O₄ is proposed for natural seawater oxidation, which requires an overpotential of only 570 mV to drive a current density of 100 mA cm^-2, and a sustained natural seawater electrolysis at 10 mA cm^-2 for 500h exhibits only 0.78 % decay. For practicability, membrane electrode with a self-developed anion exchange membrane is assembled for overall natural seawater electrolysis, and the produced hydrogen is converted to ammonia for storage by coupling nitrate reduction. Density functional theory (DFT) calculations further reveal Zr replacing an octahedral Co atom introduces four energy levels within the gap and the lower conduction band energy is formed by substituting a tetrahedral Co atom. The highest energy barrier of the second dehydrogenation step (*OH to *O) reaches 1.82 eV and it is slightly reduced to 1.79 eV after Co₃O₄ is transformed to CoOOH. Zr-adsorbed chloridion sharply increases its absorption energy on Co sites to a positive value of 0.27 eV, which effectively protects Co active sites from chloride attack.

Keywords: Anion exchange membrane; Chloride corrosion; Seawater electrolysis; Spinel; Theoretical calculation.