Enhanced chlorine enrichment via electron-deficient centers of Co(III) for efficient electrochlorination and ammonia removal

• Published in: Applied catalysis. B, Environmental Vol. 340; p. 123260
• Main Authors: Tian, Lei, Xia, Xing-Yuan, Zhou, Li-Juan, Zheng, Ling-Ling, Xing, Qiu-Ju, Zhang, Long-Shuai, Zou, Jian-Ping, Liu, Zhao-Qing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2024
• Subjects: Ammonia; Chlorine evolution reaction; Electrocatalytic system; Electron-deficient centers; Nitrogen; Ammonia; Chlorine evolution reaction; Electrocatalytic system; Electron-deficient centers; Nitrogen
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2023.123260

Subject to the sluggish enrichment kinetics of Cl- at anodic active sites, the chlorine evolution reaction (CER) activity and selectivity of current anodes are dissatisfactory for the treatment of ammonia-containing wastewater. In this study, antimony and stannum with strong electronegativity are synchronously introduced into cobaltosic oxide (Sb2O5-Co3O4/Sn) to induce the construction of Co(III) sites with robust electron-deficient centers. The formation of such electron-deficient centers of Co(III) strengthens the enrichment of Cl- and broadened the potential difference of chlorine/oxygen evolution, thereby promoting the CER activity and selectivity at low Cl- concentration. 50.0 mg/L of ammonia-nitrogen can be mineralized into nitrogen within 90 min in the EC system assembled with Sb2O5-Co3O4/Sn anode, which is superior to that of the commercial dimensionally stable anode. Finally, the system shows exceptional feasibility of practical ammonia-containing wastewater purification. This study opens novel avenues to design anodes for highly selective CER and efficient treatment of ammonia-contaminated effluents. [Display omitted] •Electron-deficient centers of Co(III) sites are formed in Sb2O5-Co3O4/Sn anode.•The enhanced enrichment of Cl- at Co(III) promotes CER activity and selectivity.•Sb2O5-Co3O4/Sn anode shows higher CER selectivity than commercial DSAs.•Sb2O5-Co3O4/Sn anode has good feasibility for the treatment of actual effluent.