Synergistic single-atom Ru and MOF-derived oxygen vacancy ZrO2-porous carbon to boost the efficiency for electrochemical nitrogen fixation

Ammonia is an important raw material for chemical, fertilizer, and energy storage. Energy-intensive industrial nitrogen fixation goes against the carbon-neutral concept and needs to be replaced by clean alternative electrochemical nitrogen fixation methods (ENF). Herein, we report a single-atom Ru loaded on MOF-derived oxygen-rich vacancies ZrO2 porous carbon material (Ru@ ZrO-PL) by plasma etching technique to enhance the ENF properties with the NH3 yield rate of 83.1 +/- 2.4 mu g h-1 mgcat- 1 and the Faradaic efficiency (FE) of 13.8 +/- 0.4 at -0.25 V vs RHE. The advanced flow cell device improves the efficiency of material transfer and greatly enhances the ENF properties of the Ru@ ZrO-PL, with an NH3 yield rate up to 113.1 +/- 6.5 mu g h-1 mgcat- 1 and FE up to 57.3 +/- 2.9% at -0.20 V vs RHE. Theoretical calculations revealed that the single-atom Ru embraced by the oxygenrich vacancy ZrO2 porous carbon enhanced the N2 adsorption activation, which was more favorable for the ENF process. This work provides new ideas for enhancing the ENF performance of single-atom materials and highlights the advantages of novel devices.