Low‐Coordinate Step Atoms via Plasma‐Assisted Calcinations to Enhance Electrochemical Reduction of Nitrogen to Ammonia
Xiaohui Yang, Faling Ling, Xiangrong Zi, Yanwei Wang, Yanwei Wang, Han Zhang, Huijuan Zhang, Miao Zhou, Zhanhu Guo, Yu Wang, Yu Wang
Abstract
Abstract The electrochemical N 2 reduction reaction (NRR) is emerging as a promising alternative to the industrial Haber–Bosch process for distributed and modular production of NH 3 . Nevertheless, developing high‐efficiency catalysts to simultaneously realize both high activity and selectivity for the development of a sustainable NRR is very critical but extremely challenging. Here, a unique plasma‐assisted strategy is developed to synthesize iridium diphosphide nanocrystals with abundant surface step atoms anchored in P,N‐codoped porous carbon nanofilms (IrP 2 @PNPC‐NF), where the edges of the IrP 2 nanocrystals are extremely irregular, and the ultrathin PNPC‐NF possesses a honeycomb‐like macroporous structure. These characteristics ensure that IrP 2 @PNPC‐NF delivers superior NRR performance with an NH 3 yield rate of 94.0 µg h −1 mg −1 cat. and a faradaic efficiency (FE) of 17.8%. Density functional theory calculations reveal that the unique NRR performance originates from the low‐coordinate step atoms on the edges of IrP 2 nanocrystals, which can lower the reaction barrier to improve the NRR activity and simultaneously inhibit hydrogen evolution to achieve a high FE for NH 3 formation. More importantly, such a plasma‐assisted strategy is general and can be extended to the synthesis of other high‐melting‐point noble‐metal phosphides (OsP 2 @PNPC‐NF, Re 3 P 4 @PNPC‐NF, etc.) with abundant step atoms at lower temperatures.