PdFe Single-Atom Alloy Metallene for N2 Electroreduction

Single-atom alloys hold great promise for electrocatalytic nitrogen reduction reaction (NRR), while the comprehensive experimental/theoretical investigations of SAAs for the NRR are still missing. Herein, PdFe1 single-atom alloy metallene, in which the Fe single atoms are confined on a Pd metallene support, is first developed as an effective and robust NRR electrocatalyst, delivering exceptional NRR performance with an NH3 yield of 111.9 mu g h(-1) mg(-1), a Faradaic efficiency of 37.8 % at -0.2 V (RHE), as well as a long-term stability for 100 h electrolysis. In-depth mechanistic investigations by theoretical computations and operando X-ray absorption/Raman spectroscopy indentify Pd-coordinated Fe single atoms as active centers to enable efficient N-2 activation via N-2-to-Fe sigma-donation, reduced protonation energy barriers, suppressed hydrogen evolution and excellent thermodynamic stability, thus accounting for the high activity, selectivity and stability of PdFe1 for the NRR.

Automated summary

In this study, PdFe1 single-atom alloy is developed as an effective electrocatalyst for nitrogen reduction reaction (NRR). Mechanistic investigations reveal that Pd-coordinated Fe single atoms serve as active centers, enabling efficient N-2 activation and exhibiting high selectivity and stability for the NRR.