Connection of Ru nanoparticles with rich defects enables the enhanced electrochemical reduction of nitrogen.

The electrochemical reduction of N 2 into NH 3 under ambient conditions is an attractive topic in the chemical industry, but the chemical inertness of N 2 and the competing hydrogen evolution reaction hamper the activity and selectivity of this reaction. Herein, we connected Ru nanocrystals through a facile annealing process, which constructed intraparticle grain boundaries and stacking faults in the connection regions to enhance the N 2 reduction reaction. The connected Ru nanoparticles exhibited an enhanced yield rate and faradaic efficiency for NH 3 production. At -0.1 V versus RHE, the connected Ru nanoparticles exhibited a maximum yield rate of 29.3 μg cm -2 h -1 (148.0 μg mg cat -1 h -1 ) for NH 3 production with a faradaic efficiency of 7.0%. Mechanistic study revealed that the promotion of the electrochemical reduction of N 2 over connected Ru nanoparticles could be attributed to the decreased work function and facilitated electron transfer, which originated from the abundant defects in the connection region.