(543i) Electrochemical Reduction of Nitrogen to Ammonia over Transition Metals

The ability to produce ammonia in a sustainable and efficient manner has been a topic of scientific and industrial importance for many years. The Haber-Bosch process has acted as the primary process for transforming nitrogen and hydrogen gas into ammonia. This process has become unsustainable in the foreseeable future and requires a cost-effective alternative. Ammonia is a critical component of fertilizer that is vital to the agriculture industry. The electrochemical reduction of N₂ to ammonia would eliminate carbon dioxide emissions that are present in current ammonia production processes and allow for a environmentally favorable process. Although the electrochemical reduction of nitrogen to ammonia has been researched as an alternative process, the high temperature and pressure requirements have not allowed for the advancement of the field. This project further investigates the potential for electrochemical reduction of nitrogen to ammonia via transition metal electrocatalysts. The challenge is to develop not only an active, but selective catalyst for ammonia production. We utilized a compact, parallel plate electrochemical cell that allowed for the study of transition metal activity for electrochemical reduction of nitrogen at ambient temperature and pressure. The product distribution resulting from the electrochemical reduction of nitrogen and the corresponding Faradaic efficiencies have been reported for first and second row transition metals. Moreover, several operating conditions were tested and electrocatalytic stability was monitored.