La-doped TiO2 nanorods toward boosted electrocatalytic N2-to-NH3 conversion at ambient conditions

Electrochemical N2 reduction provides a green and sustainable alternative to the Haber-Bosch technology for NH3 synthesis. However, the extreme inertness of N2 molecules is a formidable challenge, which requires the development of an active electrocatalyst to drive the N2 reduction reaction (NRR) for NH3 production at ambient conditions. Herein, we demonstrate the development of La-doped TiO2 nanorods as an efficient NRR electrocatalyst for ambient NH3 synthesis. The optimized La-TiO2 catalyst offers a large NH3 yield of 23.06 μg h−1 mgcat−1 and a high Faradaic efficiency of 14.54% at –0.70 V versus reversible hydrogen electrode in 0.1 M LiClO4, outperforming most La- and Ti-based catalysts reported before. Significantly, it also demonstrates high electrochemical stability and its activity decay is negligible after 48 h test. The mechanism is further revealed by density functional theory calculations.