Strong catalyst support interactions in defect-rich γ-Mo2N nanoparticles loaded 2D-h-BN hybrid for highly selective nitrogen reduction reaction

Abstract

Electrochemical ammonia synthesis by N2 fixation has proven to be a promising alternative to the energy-consuming, befouling Haber-Bosch process. Considering the low faradaic efficiency and sluggish kinetics of Nitrogen Reduction Reaction (NRR), it is significant to design a robust and selective catalyst. Herein, we demonstrate a single step in-situ nitridation method to grow cubic molybdenum nitride (γ-Mo2N) nanoparticles on a 2D hexagonal boron nitride (h-BN) sheets as a potential, cost-effective electrocatalyst for NRR, in which the selectivity for N2 was regulated by interfacially engineering the Mo2N-BN bridge. The maneuverability of h-BN sheets enabled the provocation of N-vacancies governed by the particle size, where the fine-tuning of their significance emanated the highest faradaic efficiency of 61.5 %. Moreover, such non-noble metal-based hybrids delivered a stable performance for 20 h. Therefore, our approach of designing the electronic structure of a catalyst by controlling the defects could be an effective practice for selective NRR.