Low-coordinated Pd metallene promotes the electrochemical reduction of nitrite to ammonia.

The electrochemical reduction of NO₂⁻ to NH₃ provides a promising approach for both the treatment of harmful NO₂⁻ and the sustainable production of NH₃. In this study, a low-coordinated Pd metallene (L-Pd) was first explored as an efficient NO₂RR electrocatalyst, showing an exceptional FE_NH3 value of 95.2% and a high NH₃ yield rate of 511.5 μmol h⁻¹ cm⁻². A combination of experimental and computational studies revealed that the significantly enhanced NO₂RR performance of L-Pd originates from the low-coordinated Pd sites for boosting NO₂⁻ activation and decreasing the energy barrier of the *NO → *NHO rate-determining step while suppressing the competing hydrogen evolution. [ABSTRACT FROM AUTHOR]