Lewis Acid Fe-V Pairs Promote Nitrate Electroreduction to Ammonia

Electrochemical reduction of nitrate to ammonia (NO3RR) has been recognized as an appealing approach to realize both sustainable NH3 production and waste nitrate removal. Herein, from the perspective of Lewis acid-base interaction, a single-atom Fe-doped V2O5 (Fe-V2O5) catalyst enriched is designed with Lewis acid sites, which present the maximum NH3-Faradaic efficiency of 97.1% with the corresponding NH3 yield of 12.5 mg h(-1) cm(-2) at -0.7 V versus RHE. Mechanistic studies based on theoretical calculations and operando spectroscopic characterizations identify the creation of Lewis acid Fe-V pairs on Fe-V2O5, which can synergetically activate the NO3-, promote the hydrogenation energetics, and restrain the hydrogen evolution, leading to the enhanced NO3RR activity and selectivity.

Automated summary

In this study, a single-atom Fe-doped V2O5 catalyst enriched with Lewis acid sites was designed for efficient NO3RR from the perspective of Lewis acid-base interaction. Mechanistic studies identified the formation of Lewis acid Fe-V pairs on Fe-V2O5, which synergistically activated NO3-, promoted hydrogenation energetics, and restrained hydrogen evolution, resulting in enhanced NO3RR activity and selectivity.