Enhanced electrocatalytic N2-to-NH3 fixation by ZrS2 nanofibers with a sulfur vacancy

Abstract

Industrially, large-scale NH₃ production is achieved by the Haber–Bosch process, which operates under harsh reaction conditions with abundant energy consumption and CO₂ emission. Electrochemical N₂ reduction is an eco-friendly and energy-saving method for artificial N₂ to NH₃ fixation under ambient reaction conditions. Herein, we demonstrate that ZrS₂ nanofibers with a sulfur vacancy (ZrS₂ NF–Vs) behave as an efficient electrocatalyst for ambient N₂ reduction to NH₃ with excellent selectivity. In 0.1 M HCl, this ZrS₂ NF–Vs catalyst attains a large NH₃ yield of 30.72 μg h⁻¹ mg_cat.⁻¹ and a high faradaic efficiency of 10.33% at −0.35 V and −0.30 V vs. reversible hydrogen electrode, respectively. It also shows high electrochemical and structural stability. The density functional theory calculations reveal that the introduction of Vs facilitates the adsorption and activation of N₂ molecules.