Recent Advances in Electrocatalytic Nitrate Reduction to Ammonia: Mechanism Insight and Catalyst Design

Excessive discharge of nitrate pollutants has caused an imbalance in the nitrogen cycle, which has threatened human health and ecosystems. Clean electrocatalytic nitrate reduction technology can convert nitrate into high value-added ammonia to control water pollution, truly realizing “turning waste into treasure”. This review highlights the latest mechanisms proposed by combining in situ characterization and discusses the various intermediates produced during the reaction process and the key steps that determine the reaction rate. Meanwhile, four common catalyst synthesis strategies are systematically summarized. These strategies have exhibited preeminent results in terms of conductivity and active sites and inhibition of side effects. Finally, the challenges and difficulty of electrocatalytic nitrate reduction into ammonia (NRA) in the process of development and the main development direction in the future are discussed. The engineering strategies for increasing the electrocatalytic stability and performance are also discussed. This review aims to provide guidance for efficient electrocatalytic nitrate conversion and promotes the advancement of sustainable nitrogen chemistry.