Abstract
The Haber-Bosch synthesis produces ammonia from hydrogen and nitrogen gases in a globally important energy-intensive process that uses coal or natural gas as a fuel and as a hydrogen source. Direct electrochemical ammonia synthesis from nitrogen and water using renewable energy sources presents an alternative to the Haber-Bosch process that would be sustainable and environmentally benign. Additionally, the different production structure of direct electrochemical nitrogen reduction technology suggests a supply chain alternative to the ammonia industry, and a method for load-leveling of the electrical grid. This alternative route to ammonia from dinitrogen would not require the same large capital investments as does the Haber-Bosch process, nor would it require access to a fossil fuel supply. We show that under certain scenarios, at feasibly achievable levels of energy efficiency with a future electrocatalyst, direct nitrogen reduction would be economically competitive or advantageous compared with Haber-Bosch-based ammonia production.