Promoting Nitrite-to-Ammonia Electroreduction overAmorphous CoS₂ Nanorods

Abstract

Electrocatalytic nitrite reduction to ammonia (NO₂RR) emerges as a promising route to simultaneously attain harmful NO₂^– removal and green NH₃ synthesis. In this study, amorphous CoS₂ nanorods (a-CoS₂) are first demonstrated as an effective NO₂RR catalyst, which exhibits the maximum FE_NH3 of 88.7% and NH₃ yield rate of 438.1 μmol h^–1 cm^–2 at −0.6 V vs RHE. Detailed experimental and computational investigations reveal that the high NO₂RR performance of a-CoS₂ originates from the amorphization-induced S vacancies to facilitate NO₂^– activation and hydrogenation, boost the electron transport kinetics, and inhibit the competitive hydrogen evolution.