Enhanced electrocatalytic N-2-to-NH3 fixation by ZrS2 nanofibers with a sulfur vacancy

摘要

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 N-2 reduction is an eco-friendly and energy-saving method for artificial N-2 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 N-2 reduction to NH3 with excellent selectivity. In 0.1 M HCl, this ZrS2 NF-Vs catalyst attains a large NH3 yield of 30.72 mu g 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 N-2 molecules.