Greatly Improving Electrochemical N₂ Reduction over TiO₂ Nanoparticles by Iron Doping

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrogen reduction reaction (NRR) to ammonia (NH3) requires efficient catalysts.
• Titanium dioxide (TiO2) is a promising material, but its NRR performance needs enhancement.
• Iron (Fe) doping is explored to improve TiO2-based NRR catalysts.

Purpose of the Study:

• To develop and evaluate iron-doped TiO2 nanoparticles for electrocatalytic N2 reduction to NH3.
• To assess the ammonia yield and Faradaic efficiency (FE) of the Fe-doped TiO2 catalyst.
• To investigate the catalytic mechanism using theoretical calculations.

Main Methods:

• Synthesis of Fe-doped TiO2 nanoparticles.
• Electrocatalytic testing in 0.5 M LiClO4 electrolyte.
• Ammonia yield and FE measurements at -0.40 V vs. RHE.
• Theoretical calculations to probe the catalytic mechanism.

Main Results:

• Fe-doped TiO2 catalyst achieved a high FE of 25.6% and NH3 yield of 25.47 μg h−1 mg−1.
• Performance surpasses previously reported titanium- and iron-based NRR electrocatalysts in aqueous media.
• Theoretical calculations provided insights into the catalytic mechanism.

Conclusions:

• Fe-doped TiO2 nanoparticles are highly effective electrocatalysts for N2 to NH3 conversion.
• The catalyst demonstrates superior performance in terms of NH3 yield and FE.
• This study offers a promising pathway for efficient ammonia synthesis via electrocatalysis.