Low platinum loading Co3O4 electrode for highly efficient oxidation of ammonia in aqueous solution

Abstract

Chlorine-mediated electrochemical advanced oxidation (Cl-EAO) is an environmentally-friendly and promising ammonia removal technology to convert ammonia to N2 and effectively reduce water pollution. The efficiency of ammonia removal in Cl-EAO hinges critically on the performance of the electrode materials. Currently, precious metal oxides are commonly used as electrode materials in the industry. However, their high cost limits their widespread application in ammonia treatment. Herein, Pt-Co3O4 catalyst with lutra-low content of Pt (1.67 wt%) is successfully synthesized, which performs superior CER activity and higher removal efficiency of ammonia. The favorable catalytic performance could be attributed to the increase in oxygen vacancy content and the strong metal-supported strong interaction (SMSI) between Pt and Co3O4, which has been confirmed by XPS. Especially, the chlorine evolution efficiency of the Ti/Pt3 %-Co3O4 electrode was as high as 96 % in dilute chloride (<50 mM) solution at a current density of 10 mA/cm2. Therefore, the Ti/Pt3 %-Co3O4 electrode has a broad application prospect as a new and efficient material for ammonia wastewater treatment.