High-ammonia selective metal-organic framework-derived Co-doped Fe/Fe₂O₃ catalysts for electrochemical nitrate...

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Ammonia (NH3) is a key carbon-free fuel for the sustainable hydrogen economy.
• Electrochemical nitrate reduction (NO3-RR) offers a route for nitrate removal and NH3 production but requires efficient catalysts.

Purpose of the Study:

• To develop and evaluate a novel MOF-derived catalyst for electrochemical nitrate reduction.
• To achieve high efficiency in NH3 production and nitrate removal.

Main Methods:

• Synthesis of a metal-organic framework (MOF)-derived cobalt-doped Fe@Fe2O3 (Co-Fe@Fe2O3) catalyst.
• Electrochemical testing of the catalyst for NO3-RR.
• Experimental and computational analysis to understand catalytic mechanisms.

Main Results:

• The Co-Fe@Fe2O3 catalyst demonstrated a nitrate removal capacity of 100.8 mg N gcat−1 h−1 and 99.0% ammonium selectivity.
• NH3 production rate reached 1,505.9 μg h−1 cm−2 with a maximum Faradaic efficiency of 85.2%.
• Cobalt doping tuned the Fe d-band center, optimizing intermediate adsorption and suppressing hydrogen evolution.

Conclusions:

• The Co-Fe@Fe2O3 catalyst represents a significant advancement in electrocatalysts for NO3-RR.
• Cobalt doping is an effective strategy for enhancing catalyst performance in electrochemical nitrate reduction.
• This work provides a pathway for designing efficient electrocatalysts for sustainable energy production.