Greatly Improving Electrochemical N₂ Reduction over TiO₂ Nanoparticles by Iron Doping

Abstract Titanium‐based catalysts are needed to achieve electrocatalytic N 2 reduction to NH 3 with a large NH 3 yield and a high Faradaic efficiency (FE). One of the cheapest and most abundant metals on earth, iron, is an effective dopant for greatly improving the nitrogen reduction reaction (NRR) performance of TiO 2 nanoparticles in ambient N 2 ‐to‐NH 3 conversion. In 0.5 m LiClO 4 , Fe‐doped TiO 2 catalyst attains a high FE of 25.6 % and a large NH 3 yield of 25.47 μg h −1 mg cat −1 at −0.40 V versus a reversible hydrogen electrode. This performance compares favorably to those of all previously reported titanium‐ and iron‐based NRR electrocatalysts in aqueous media. The catalytic mechanism is further probed with theoretical calculations.