Oriented Synthesis of Glycine from CO2, N2, and H2O via a Cascade Process.

Air contains carbon, hydrogen, oxygen, and nitrogen elements that are essential for the constitution of amino acids. Converting the air into amino acids, powered with renewable electricity, provides a green and sustainable alternative to petrochemical-based methods that produce waste and pollution. Here, taking glycine as an example, we demonstrated the complete production chain for electrorefining amino acids directly from CO2, N2, and H2O. Such a prospective scheme was composed of three modules, linked by a spontaneous C-N bond formation process. The high-purity bridging intermediates, separated from the stepwise synthesis, boosted both the carbon selectivity from CO2 to glycine of 91.7% and nitrogen selectivity from N2 to glycine of 98.7%. Under the optimum condition, we obtained glycine with a partial current density of 160.8 mA cm-2. The high-purity solid glycine product was acquired with a separation efficiency of 98.4%. This work unveils a green and sustainable method for the abiotic creation of amino acids from the air components.