Efficient N 2 electroreduction enabled by linear charge transfer over atomically dispersed W sites.

Electrocatalytic nitrogen reduction reaction (NRR) presents a sustainable alternative to the Haber-Bosch process for ammonia (NH 3 ) production. However, developing efficient catalysts for NRR and deeply elucidating their catalytic mechanism remain daunting challenges. Herein, we pioneered the successful embedding of atomically dispersed (single/dual) W atoms into V 2- x CT y via a self-capture method, and subsequently uncovered a quantifiable relationship between charge transfer and NRR performance. The prepared n-W/V 2- x CT y shows an exceptional NH 3 yield of 121.8 μg h -1 mg -1 and a high faradaic efficiency (FE) of 34.2% at -0.1 V ( versus reversible hydrogen electrode (RHE)), creating a new record at this potential. Density functional theory (DFT) computations reveal that neighboring W atoms synergistically collaborate to significantly lower the energy barrier, achieving a remarkable limiting potential ( U L ) of 0.32 V. Notably, the calculated U L values for the constructed model show a well-defined linear relationship with integrated-crystal orbital Hamilton population (ICOHP) ( y = 0.0934 x + 1.0007, R 2 = 0.9889), providing a feasible activity descriptor. Furthermore, electronic property calculations suggest that the NRR activity is rooted in d-2π* coupling, which can be explained by the "donation and back-donation" hypothesis. This work not only designs efficient atomic catalysts for NRR, but also sheds new insights into the role of neighboring single atoms in improving reaction kinetics.