Enhancing Electrocatalytic NO Reduction to NH 3 by the CoS Nanosheet with Sulfur Vacancies.

Electrochemical reduction of NO to NH 3 is of great significance for mitigating the accumulation of nitrogen oxides and producing valuable NH 3 . Here, we demonstrate that the CoS nanosheet with sulfur vacancies (CoS 1- x ) behaves as an efficient catalyst toward electrochemical NO-to-NH 3 conversion. In 0.2 M Na 2 SO 4 electrolyte, such CoS 1- x displays a large NH 3 yield rate (44.67 μmol cm -2 h -1 ) and a high Faradaic efficiency (53.62%) at -0.4 V versus the reversible hydrogen electrode, outperforming the CoS counterpart (27.02 μmol cm -2 h -1 ; 36.68%). Moreover, the Zn-NO battery with CoS 1- x shows excellent performance with a power density of 2.06 mW cm -2 and a large NH 3 yield rate of 1492.41 μg h -1 mg cat. -1 . Density functional theory was performed to obtain mechanistic insights into the NO reduction over CoS 1- x .