In Situ Phase Separation-Induced Self-Healing Catalyst for Efficient Direct Seawater Electrolysis

• Published in: ACS nano Vol. 18; no. 25; pp. 16312 - 16323
• Main Authors: Zhang, Yihan, Jeong, Seulgi, Son, Eunbin, Choi, Yunseong, Lee, Sangjin, Baik, Jeong Min, Park, Hyesung
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 25.06.2024
• Subjects: direct seawater electrolysis; amorphous phase; precipitate waste recover; corrosion resistance; interface engineering
• ISSN: 1936-0851; 1936-086X; 1936-086X
• DOI: 10.1021/acsnano.4c06220

Direct seawater electrolysis technology for sustainable hydrogen production has garnered significant attention, owing to its abundant resource supply and economic potential. However, the complex composition and high chloride concentration of seawater have hindered its practical implementation. In this study, we report an in situ-synthesized dual-phase electrocatalyst (HPS–NiMo), comprising an amorphous phosphide protective outer phase and a crystalline alloy inner phase with supplementary sulfur active sites, to improve the kinetics of direct seawater electrolysis. The HPS–NiMo exhibits long-term stability, remaining stable for periods exceeding 120 h at 200 mA cm–2; moreover, it lowers the required operating voltage to ∼1.8 V in natural seawater. The chlorine chemistry, corrosion during direct natural seawater electrolysis, and mechanism behind the high-performing catalysts are discussed. We also investigated the possibility of recovering the anode precipitates, which inevitably occurs during seawater electrolysis.