Review on electrocatalytic nitrate reduction to ammonia: advances, challenges and future prospects
摘要
Ammonia (NH3), an indispensable component of the fertiliser industry, plays an important role in human life. Owing to negative environmental impacts and the high energy input of the industrial Haber-Bosch process, uncovering alternative sustainable technologies for NH3 production is crucial. Anthropogenic activities leading to an imbalance in the nitrogen cycle have resulted in excessive nitrate (NO3−) pollution. Electrochemical conversion of NO3− pollutant into value-added NH3 is a recent trend in wastewater management. Additionally, this method provides an added leverage of circumventing the need for highly inert nitrogen gas as a precursor in electrochemical NH3 synthesis. Therefore, the electrochemical nitrate reduction reaction (eNO3− RR) with a higher production rate and faradaic efficiency could be an appealing route for wastewater treatment and sustainable NH3 production. In this review article, an effort is made to provide an overview of the mechanisms involved, recent developments made on various electrocatalysts and also on NH3 quantification methods in eNO3− RR. Finally, this review article emphasises existing challenges and future outlooks in this field of research. This review article promotes ongoing research endeavours in the efficient conversion of NO3− into NH3.