Atomic modulation and phase engineering of MoS2 for boosting N2 reduction

Abstract

Electrochemical nitrogen reduction reaction (ENRR) has emerged as a potential alternative to the conventional Haber-Bosch process for ammonia production. However, ENRR technology is still restricted by the limited Faradaic efficiency due to the hard-to-break N-N triple bond. Herein, inspired by the biomimetic catalyst, we developed a Fe-modulated MoS2 catalyst (named Fe@MoS2) as an efficient ENRR catalyst. Raman spectra, coupled with the X-ray absorption spectroscopy, demonstrate the introduction of Fe into the MoS2 lattice and achieve partial 2H to 1T phase conversion. The presence of S-vacancies on MoS2 substrates was observed on scanning transmission electron microscopy images. Operando infrared absorption spectroscopy confirms that the constructed catalytic site significantly reduces barriers to nitrogen activation. The synthesized Fe@MoS2, with its superior geometric and electronic structures, exhibits a remarkable Faradaic efficiency of 19.7 ± 5.5% at -0.2 V vs. Reversible Hydrogen Electrode and a high yield rate of 20.2 ± 5.3 μg h-1 mg-1 at -0.8 V vs. Reversible Hydrogen Electrode. Therefore, this work provides a fresh direction for designing novel catalysts, eventually boosting the nitrogen reduction reaction kinetics and accelerating the ENRR application.