The electrochemical kinetics of chloride oxidation over multi-metallic Pt-Ni-Co electrodes affected by metal deposition method and electrode support

• Published in: Electrochimica acta 2023-11, Vol.469, p.143294, Article 143294
• Main Authors: Li, Wanze, Lin, Jui-Yen, Huang, Chin-Pao
• Format: Article
• Language: English
• Subjects: Chloride electro-oxidation; Electrode supports; Multi-metallic electrode; Multistep electrode deposition
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2023.143294

•Pt, Ni, Co-oxides were deposited on different support materials in multistep method.•The electrochemical deposition method affected surface morphology and electroactive area.•Electrode morphology affected chlorine generation rate.•Electrode support materials play a role in chlorine generation.•Graphite exhibited better chlorine production than other electrode supports. Platinum, nickel, and cobalt oxides were coated on different electrode supports (graphite, stainless steel mesh, Ti foil and Ni form) by multistep electrode deposition method. Scanning electron microscopy, X-Ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammetry and linear sweep voltammetry were used to characterize electrodes. Results showed that the deposition process, such as applied current and deposition time, and the substrates influenced electrode morphology and electrochemical chlorine generation capability. Porous structure and Co3O4 crystalline could promote chloride oxidation on electrode surface. Graphite substrate exhibited the benefit of chloride oxidation and 0.6A × 20 s× 30 is the optimal deposition condition for electrode fabrication. The 0.6A × 20 s× 30-G electrode has the lowest chlorine evolution potential, largest difference in water oxidation and chloride oxidation potential, and the smallest transfer coefficient (α), meaning that this electrode is more favorable to chloride oxidation than other electrodes. Moreover, a mechanism of chlorine generation has been proposed in this study, indicating that chlorine radicals were formed on electrode surface. The high chlorine generation capability and good durability of Pt-Ni-Co-G electrode has the potential for application in water treatment process, such as disinfection and inorganic or organic pollutants decontamination. [Display omitted]