Oxygen Vacancies in Ta2O5 Nanorods for Highly Efficient Electrocatalytic N2 Reduction to NH3 under Ambient Conditions

Electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions is emerging as a potential alternative to the Haber–Bosch process when cost and environmental protection are considered. Furthermore, the grand challenge on N 2 activation encourages development of efficient NRR catalysts. Herein, we report the positive effect of oxygen vacancies in Ta 2 O 5 nanorods for effective N 2 reduction. Density functional theory calculations reveal that N 2 can be efficiently activated at the O-vacancy site via coordination with two Ta atoms adjacent to the O-vacancy. Electrocatalytic NRR experiments verify the superior catalytic performance of O-vacancy-engineered Ta 2 O 5 nanorods (NH 3 yield, 15.9 μg h –1 mg –1 cat; Faradaic efficiency, 8.9%). This work clearly demonstrates the significance of defect engineering on the NRR field.