CoO (1 1 1) nanowire arrays for High-efficiency electrochemical nitrate reduction to ammonia.

• CoO nanowire array on titanium mesh is prepared for nitrate reduction to ammonia. • Such catalyst achieves high Faraday efficiency of 95.1% and a NH 3 yield of 6.8 mg h−1 cm−2 at − 0.6 V. • Material calculations confirm the alternating reaction pathway for this catalyst. Efficient and robust catalysts are significant for electrochemical nitrate reduction to value-added ammonia (NH 3). Here, we propose CoO (1 1 1) nanowire array on titanium mesh (CoO NWA/TM) as a high-efficiency electrocatalyst for NO 3 − conversion to NH 3. This catalyst reaches a remarkable NH 3 yield of 6.8 mg h−1 cm−2 and a high Faradaic efficiency of 95.1%, which also shows excellent electrochemical durability. The catalytic mechanism of CoO NWA/TM is revealed by theoretical calculations. [ABSTRACT FROM AUTHOR]