Construction of CuO/Co 3 O 4 Heterojunction Catalyst for High‐Efficiency Ammonia Synthesis via Nitrate Reduction

ABSTRACT Electrochemical nitrate reduction reaction (NO 3 RR) offers a sustainable approach to convert nitrate pollutants into ammonia (NH 3 ). However, challenges such as low NH 3 yield, competition from the hydrogen evolution reaction (HER), and limited nitrate adsorption restrict its efficiency. Here, we developed CuO/Co 3 O 4 heterojunction catalysts with strong interfacial coupling that synergistically modulate the electronic structure to promote efficient electron transfer. This enhances nitrate adsorption and activation while suppressing HER by accelerating active hydrogen species formation. The catalyst demonstrated a high Faradaic efficiency (FE) of 94.58%, accompanied by an NH 3 production rate of 2306.44 µmol h −1 mg −1 . Notably, it exhibited exceptional durability.