Single-atom catalysts templated by metal-organic frameworks for electrochemical nitrogen reduction
Electrocatalytic nitrogen reduction reaction (NRR) has much prospect for substituting the energy-consuming Haber-Bosch process. Nevertheless, its sluggish reaction kinetics and the competing hydrogen evolution reaction always result in limited ammonia yield and low Faradaic efficiency (FE). In this work, the Fe-decorated porphyrinic metal-organic framework (MOF) is employed as a precursor to construct single-atom Fe implanted nitrogen-doped carbon catalysts (Fe1-N-C) through a mixed ligand strategy. Benefiting from the highly dispersed single-atom Fe sites, hierarchically porous structure and good conductivity, Fe1-N-C shows a FE of 4.51% and ammonia yield rate of 1.56×10-11 mol cm-2 s-1 at -0.05 V versus reversible hydrogen electrode, superior to those of Co1-N-C and Ni1-N-C. Theoretical calculations reveal that Fe1-N-C shows the lowest energy barrier of the rate-determining step during NRR process, accordant to its highest activity obtained in experiments. This work reveals the unique potential of single-atom catalysts for electrochemical NRR and provides in-depth insights into the catalytic mechanism of NRR.
- This article is part of the themed collection: 2019 Journal of Materials Chemistry A HOT Papers