Synthesis of carbon-based catalysts with stability using Cu-BTC as precursor for electrocatalytic nitrate reduction

Electrocatalytic nitrate reduction reaction (ENRR) to recyclable ammonia has become a green treatment NO3– technology for wastewater. However, poor stability of Cu-based electrocatalysts hinders their application. In this study, three derived catalysts were prepared using Cu-BTC as a precursor at different temperatures: Cu@C-250, Cu@C-350, and Cu@C-450. The catalysts' activity was investigated through a series of nitrate reduction performance tests, and the reaction mechanism was explored through various characterization methods. The batch ENRR test revealed that Cu@C-350 exhibited the best performance in terms of NO3– removal rate (73.70 %) and faradaic efficiency for NH4+ (80.01 %) at –0.58 V vs. RHE. EIS and XPS analyses show that Cu+ accelerates electron transfer, reduce interfacial resistance, and interact with catalytic carriers to enhance the adsorption of NO3–. Additionally, the durability as an electrocatalyst is verified by consecutive cycling tests. Therefore, the use of roasted carbon material derivatives as electrocatalysts for the purification of nitrate-contaminated wastewater is a reliable strategy.