Selenium-vacancy-rich WSe for nitrate electroreduction to ammonia.

Electrocatalytic nitrate reduction to ammonia (NORR) is an attractive route for renewable NH electrosynthesis. Herein, we demonstrated Se-vacancy-rich WSe (WSe) nanoplatelets as a highly efficient NORR catalyst, exhibiting a NH-Faradaic efficiency of 92.7 % with the corresponding NH yield of 2.42 mg h cm at -0.8 V, substantially surpassing Se-vacancy-free WSe nanoplatelets. Theoretical computations by density function theory calculations and molecular dynamics simulations revealed that the introduced Se-vacancy enabled the creation of unsaturated W sites as active centers to strongly activate the NO and reduce the reaction barriers to boost the NORR process.