Bimetallic CuCo nanocrystals to tailor absorption energy of intermediators for efficient electrochemical nitrate conversion to ammonia in neutral electrolyte

Electrocatalytic nitrate reduction to ammonia (NRA) is a promising approach to solve nitrate elimination for ammonia synthesis under mild conditions, but there still lack efficient NRA electrocatalysts. Herein, we devel-oped a bimetallic CuCo nanocrystal with 2.5 at.% Co to Cu, which achieves 100% nitrate conversion rate and also maintains a high NH3 Faradaic efficiency of 95% at-0.65 V vs. RHE in neutral electrolyte. More importantly, its high catalytic activity enables a conversion rate of more than 97% for nitrate to ammonia. Density functional theory calculation reveals that the excellent catalytic activity is attributed to a strong NO3- absorption together with suppression of hydrogen evolution reaction. This work provides a new insight for developing highly active and selective NRA electrocatalysts.

Automated summary

In this study, a bimetallic CuCo nanocrystal with 2.5 at.% Co to Cu was developed, which exhibited 100% nitrate conversion rate and 95% NH3 Faradaic efficiency in neutral electrolyte. The high catalytic activity can be attributed to strong NO3- absorption and suppression of hydrogen evolution reaction.