Electrocatalytic coupling of anodic nitrogen oxidation and cathodic nitrate reduction for ammonia synthesis from air and water

Ammonia plays a vital role in present agriculture and industry, and is also regarded as a next-generation clean energy carrier. The development of electrocatalysis raises an opportunity to make ammonia synthesis compatible with intermittent and variable renewable energy sources such as solar and wind energy. However, the direct ammonia electrosynthesis from N2 reduction is still challenging due to the much easier hydrogen evolution competition reaction. In this perspective, we propose a novel strategy for ammonia electrosynthesis from air and water based on the coupling of anodic nitrogen oxidation and cathodic nitrate reduction. Possible methods for breaking the bottlenecks of anodic nitrogen oxidation and cathodic nitrate reduction are discussed separately. After that, key issues that need to be considered in the coupled system are proposed for the application of this strategy.