Atomically dispersed Pd on ZrO2 for efficient nitrite electroreduction to ammonia

Abstract

Electrochemical conversion of NO₂⁻ to NH₃ (NO₂RR) provides an appealing route to enable effective wastewater treatment and sustainable NH₃ production. Herein, we report that atomically dispersed Pd on ZrO₂ as substrate (Pd₁/ZrO₂) serves as an effective and durable NO₂RR catalyst, showing a maximum NH₃-faradaic efficiency of 96.75% and corresponding NH₃ yield rate of 438.06 μmol h⁻¹ cm⁻² at −0.6 V. Combining experiments with theoretical calculations revealed that Pd₁ incorporation enables the construction of unique Zr–Pd₁–O motifs that can effectively activate NO₂⁻, optimize the intermediate adsorption energies and suppress the competing H₂ evolution, resulting in greatly enhanced NO₂RR activity and selectivity.