Spontaneous Reaction of Electrocatalyst Resulted in a NH3 Faraday Efficiency of More than 100% in Electrochemical Nitrate Reduction

Abstract Ammonia is emerging as a liquefied and renewable‐energy carrier of global interest in the future. The electrochemical reduction of nitrate is widely acknowledged as an alternative to the traditional Haber–Bosch process for ammonia production. However, it is observed that certain catalysts can undergo spontaneous oxidation–reduction reactions with nitrate to some extent, leading to the calculated ammonia Faradaic efficiency exceeding 100%. However, there is a lack of accurate experimental validation as well as effective solutions. To address these problems, it is verified that the spontaneous reaction between the catalyst and nitrate impacts on the calculation of electrocatalytic nitrate reduction performance. Meanwhile, an updated and optimized experimental strategy is proposed to address the interference caused by the spontaneous reaction. This work will significantly contribute to more accurate and reliable electrocatalytic nitrate reduction research.