Copper 3D-Printed Electrodes for Ammonia Electrosynthesis via Nitrate Reduction

Ammonia is critical to the world economy. However, nowadays the production of ammonia is exclusively carried out by the well-known Haber-Bosch process, which is an energy-intensive process that leads to a large amount of CO2 emissions. The search for alternative ammonia production routes is mandatory for a sustainable and zero emissions future economy. Electrochemical nitrate-to-ammonia conversion emerges as a suitable alternative to achieve decentralized ammonia production at a small scale with zero emissions perspective. Here, we fabricate copper electrodes by a three-dimensional (3D) printing technique, which allows for the point-of-use customizable fabrication of electrochemical systems, and use them for nitrate-to-ammonia conversion. By using the fused fabrication filament printing technique, Cu-based electrodes were prepared in an easy, fast, and scalable way from a Cu-containing filament. The electrode was used for nitrate-to-ammonia conversion, obtaining an outstanding faradaic efficiency (FE) of 96.5% and a high ammonia selectivity of 95%. The fabrication of a copper-based electrochemical system for nitrate-to-ammonia conversion paves the way for an on-demand, point-of-use scalable electrochemical system for ammonia production.

Automated summary

Ammonia plays a critical role in the global economy. However, the current method of ammonia production through the Haber-Bosch process is energy-intensive and results in significant CO2 emissions. Finding alternative methods of ammonia production is essential for achieving a sustainable and zero emissions future economy. Electrochemical nitrate-to-ammonia conversion, using copper electrodes fabricated through 3D printing, offers a decentralized and zero emissions approach for ammonia production. The use of fused fabrication filament printing technique allows for easy, fast, and scalable production of Cu-based electrodes, resulting in high faradaic efficiency and ammonia selectivity.