The electrocatalytic nitrate reduction reaction (eNO3RR) offers a sustainable strategy for both NO3 - wastewater remediation and value-added NH3 production. However, its application is hindered by sluggish reaction kinetics in neutral media due to the limited availability of protons. Herein, an anionic metal-organic framework (MOF), SU-102, is functionalized with atomically dispersed Fe sites to yield SU-102-Fe. This catalyst achieves a Faradaic efficiency (FE) of 96.9% and NH3 production rate of 1.72 mg h-1 mgcat -1 at -0.7 V versus RHE, far surpassing the commercial Fe2O3 and pristine SU-102. In situ characterizations reveal that the negatively charged Zr─O units in SU-102 create an anionic microenvironment around the Fe sites, which enriches K+•H2O species derived from the interfacial hydrogen-bonding network. The facile dissociation of K+•H2O improves local proton supply, facilitating NO3 --to-NH3 conversion and accounting for the superior eNO3RR performance of SU-102-Fe.
Chen et al. (Sat,) studied this question.