Sustainable Green Ammonia Production from Water and Air at Room Temperature.

Abstract

Plasma-electrocatalytic ammonia (NH₃) synthesis using renewable energy as an input is an ideal and sustainable method for NH₃ production. However, its practical application is hindered by the inferior performance of the plasma nitrogen oxidation reaction (pNOR) and its inability to proceed synchronously with the electrochemical nitrate-nitrite reduction reaction (eNO_<i>x</i>^-RR) process. Herein, a bifunctional Co-P catalyst supported on Ni foam (Co-P/NF) achieves outstanding performance in both pNOR (NO_<i>x</i>^- yield: 171.3 mmol h^-1) and eNO_<i>x</i>^-RR (NH₃ yield: 319.2 mg h^-1 cm^-2; Faraday efficiency: 99.2%). More importantly, an integrated scaled-up device is further constructed, enabling gram-scale NH₃ production (1.53 g h^-1) directly from air and water. Experimental studies reveal that P-doping modulates the catalyst structure, facilitates N₂ adsorption, and accelerates the pNOR rate-determining step. Meanwhile, it optimizes H₂O dissociation to supply abundant H* species for the hydrogenation process in the eNO_<i>x</i>^-RR. This synergistic mechanism collectively enables the remarkable NH₃ yield.