Selenium-vacancy-rich WSe2 for nitrate electroreduction to ammonia

Electrocatalytic nitrate reduction to ammonia (NO3RR) is an attractive route for renewable NH3 electrosynthesis. Herein, we demonstrated Se-vacancy-rich WSe2 (WSe2-x) nanoplatelets as a highly efficient NO3RR catalyst, exhibiting a NH3-Faradaic efficiency of 92.7 % with the corresponding NH3 yield of 2.42 mg h-1 cm-2 at -0.8 V, substantially surpassing Se-vacancy-free WSe2 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 NO3- and reduce the reaction barriers to boost the NO3RR process.