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 Ta2O5 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 Ta2O5 nanorods (NH3 yield, 15.9 mu g h(-1) mg(cat)(-1); Faradaic efficiency, 8.9%). This work clearly demonstrates the significance of defect engineering on the NRR field.