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

Electrocatalytic NO reduction to NH3 (NORR)offers aprospective method for removing hazardous NO and producing valuableNH(3) simultaneously. Herein, we demonstrate that atomicallydispersed W on Pd metallene (W1Pd) can be an efficientand robust NORR catalyst. Atomic coordination characterizations unravelthat W single atoms exist as W-1-O-3 moietiesbonded on Pd metallene. In situ spectroscopic measurements and theoreticalcalculations reveal the synergistic cascade effect of W-1-O-3 and Pd metallene to promote the NORR energeticsof W1Pd, in which the activation and hydrogenation of NOoccur on W-1-O-3, while Pd metallene dissociatesH(2)O and donates protons required for hydrogenation of NOto NH3. Consequently, W1Pd exhibits an NH3 yield rate of 758.5 & mu;mol h(-1) cm(-2) with an NH3-Faradaic efficiency of 91.3%in a flow cell (272.1 & mu;mol h(-1) cm(-2) and 93.7% in H-type cells), ranking almost the highest performanceamong all reported NORR catalysts.