NH2–MIL-88B–Fe for electrocatalytic N2 fixation to NH3 with high Faradaic efficiency under ambient conditions in neutral electrolyte

The global NH 3 production is dominated by Haber–Bosch process, requiring high temperature and pressure. Electrochemical N 2 reduction reaction (NRR) under ambient conditions is a greener path for artificial N 2 fixation to NH 3 but calling for efficient catalyst to increase activity and selectivity. Herein, we report the iron-based metal–organic frameworks (MOFs), i.e., MIL-88B–Fe and amine-functionalized MIL-88B–Fe (NH 2 –MIL-88B–Fe) as efficient catalysts for electrochemical NRR under ambient temperature and pressure in neutral electrolyte. NH 2 –MIL-88B–Fe shows higher NH 3 yield rate of 1.205 × 10 –10  mol s −1  cm −2 than MIL-88B–Fe (3.575 × 10 –11  mol s −1  cm −2 ). Furthermore, NH 2 –MIL-88B–Fe exhibits the highest Faradaic efficiency of 12.45% at 0.05 V versus RHE. The control experiments prove that NH 3 is produced through electrocatalytic NRR. This work may trigger the interest of using MOFs as highly efficient catalysts for electrochemical NH 3 production.