(Invited) Mechanisms of Nitrogen Cycle Electrochemistry for Energy and Sustainability

The production scale of ammonia is significant and is continuing to expand for applications in agriculture and energy. The degradation of its access is imperative to nitrogen balance. While at present thermocatalytic reactions to produce ammonia (Haber-Bosch process), nitric acid (Ostwald process) and urea (Bosch-Meiser process) dominate the artificial nitrogen cycle, the transition to sustainable production is currently driven by the development of electrochemical methods to replace traditional practices. Nitrogen cycle electrocatalysis, including nitrogen fixation, degradation and transformation of available nitrogen are attracting considerable attention in recent years. This talk will first briefly overview the emerging electrocatalytic technologies for both sustainable production of ammonia/urea and ammonia pollution mitigation; after this introduction, the talk will focus on the developments in electrooxidative ammonia and urea transformations in the broader context of nitrogen cycle and the complementarity and synergy of nitrogenous waste electrooxidation with cathodic production of fuels; finally, it will provide mechanistic insights into these electrocatalytic transformations to facilitate rational reaction and catalyst design.