High catalytic performance of CuCo/nickel foam electrode for ammonia electrooxidation

Abstract

As part of ongoing efforts to effectively remove ammonia from industrial wastewater, electrochemical oxidation has become an alternative to conventional biological treatment due to its easier operation and better tolerance of toxic pollutants. This study aims to prepare CuCo/nickel foam (CuCo/NF) electrodes by depositing different ratios of Cu and Co as catalysts and investigate their performance for ammonia electrooxidation (EO). Under optimum conditions (pH 11 and applied voltage of 1.1 V vs Ag/AgCl), excellent ammonia removal was obtained using the Cu0.5Co0.5/NF electrode system, with 93% removal after 5 h for a low level of ammonia loading (50 mg-N/L), which was superior to the performance of the bare NF electrode (only 54%). The Cu0.5Co0.5/NF electrode also had a higher current efficiency of 34% and lower energy consumption of 0.11 kWh g−1 compared to the bare NF and single metal Cu (Cu1Co0/NF) or Co (Cu0Co1/NF) electrodes. The high catalytic performance of the Cu0.5Co0.5/NF electrode towards ammonia indicates that a CuCo bimetallic catalyst on a NF substrate is a promising solution for effective removal of ammonia from industrial wastewater.

Keywords

• Ammonia
• CuCo catalyst
• Selective nitrification
• Electrooxidation (EO)