Self-Tandem Electrocatalytic NO Reduction to NH<sub>3</sub> on a W Single-Atom Catalyst
Kai Chen, Jiaxin Wang, Hu Zhang, Dongwei Ma, Ke Chu
Abstract
We design single-atom W confined in MoO 3– x amorphous nanosheets (W 1 /MoO 3– x ) comprising W 1 –O 5 motifs as a highly active and durable NORR catalyst. Theoretical and operando spectroscopic investigations reveal the dual functions of W 1 –O 5 motifs to (1) facilitate the activation and protonation of NO molecules and (2) promote H 2 O dissociation while suppressing *H dimerization to increase the proton supply, eventually resulting in a self-tandem NORR mechanism of W 1 /MoO 3– x to greatly accelerate the protonation energetics of the NO-to-NH 3 pathway. As a result, W 1 /MoO 3– x exhibits the highest NH 3 –Faradaic efficiency of 91.2% and NH 3 yield rate of 308.6 μmol h –1 cm –2, surpassing that of most previously reported NORR catalysts.