Atomically Dispersed W₁–O₃ Bonded on Pd Metallene for Cascade NO Electroreduction to NH₃

Abstract

Electrocatalytic NO reduction to NH 3 (NORR) offers a prospective method for removing hazardous NO and producing valuable NH 3 simultaneously. Herein, we demonstrate that atomically dispersed W on Pd metallene (W 1 Pd) can be an efficient and robust NORR catalyst. Atomic coordination characterizations unravel that W single atoms exist as W 1 –O 3 moieties bonded on Pd metallene. In situ spectroscopic measurements and theoretical calculations reveal the synergistic cascade effect of W 1 –O 3 and Pd metallene to promote the NORR energetics of W 1 Pd, in which the activation and hydrogenation of NO occur on W 1 –O 3, while Pd metallene dissociates H 2 O and donates protons required for hydrogenation of NO to NH 3 . Consequently, W 1 Pd exhibits an NH 3 yield rate of 758.5 μmol h –1 cm –2 with an NH 3 -Faradaic efficiency of 91.3% in a flow cell (272.1 μmol h –1 cm –2 and 93.7% in H-type cells), ranking almost the highest performance among all reported NORR catalysts.