Single Atoms of Iron on MoS₂ Nanosheets for N₂ Electroreduction into Ammonia

Abstract

Efforts have been devoted to achieving a highly efficient artificial synthesis of ammonia (NH₃ ). Reported herein is a novel Fe-MoS₂ catalyst with Fe atomically dispersed onto MoS₂ nanosheets, imitating natural nitrogenase, to boost N₂ electroreduction into NH₃ at room temperature. The Fe-MoS₂ nanosheets exhibited a faradic efficiency of 18.8 % with a yield rate of 8.63 μg <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow></mml:mrow> <mml:mrow><mml:mi>NH</mml:mi> <mml:msub><mml:mrow></mml:mrow> <mml:mn>3</mml:mn></mml:msub> </mml:mrow> </mml:msub> </mml:math> mg_cat. ^-1 h^-1 for NH₃ at -0.3 V versus the reversible hydrogen electrode. The mechanism study revealed that the electroreduction of N₂ was promoted and the competing hydrogen evolution reaction was suppressed by decorating the edge sites of S in MoS₂ with the atomically dispersed Fe, resulting in high catalytic performance for the electroreduction of N₂ into NH₃ . This work provides new ideas for the design of catalysts for N₂ electroreduction and strengthens the understanding about N₂ activation over Mo-based catalysts.