Spin regulation for efficient electrocatalytic N₂ reduction over diatomic Fe-Mo catalyst.

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Electrocatalytic nitrogen reduction reaction (eNRR) offers a sustainable alternative to the energy-intensive Haber-Bosch process for ammonia synthesis.
• Developing efficient and selective electrocatalysts is crucial for advancing eNRR technology.

Purpose of the Study:

• To investigate atomic spin regulation as a strategy to enhance electrocatalytic nitrogen reduction reaction (eNRR) performance.
• To screen and identify efficient Fe-transition metal (TM) hybrid heteronuclear dual-atom catalysts for eNRR.
• To elucidate the mechanism behind spin regulation in promoting eNRR activity and selectivity.

Main Methods:

• Density Functional Theory (DFT) computations were employed to systematically investigate 30 Fe-based dual-atom catalysts anchored on N-doped porous graphene.
• Calculations assessed catalyst stability, activity, and selectivity for the eNRR.
• Spin states and electronic interactions of active sites with reaction intermediates were analyzed.

Main Results:

• Fe/MoNC was identified as a highly efficient eNRR catalyst with a low limiting potential of 0.63 V, also suppressing the hydrogen evolution reaction (HER).
• Atomic spin regulation by Fe modified the spin state of the Mo center in MoN4, reducing orbital overlap with intermediates and facilitating product desorption.
• The findings align with the FeMo-cofactor structure found in nitrogenase, suggesting a similar catalytic principle.

Conclusions:

• Atomic spin regulation is an effective strategy for designing high-performance eNRR catalysts.
• Fe/MoNC demonstrates significant potential for sustainable ammonia production via eNRR.
• This work provides insights into nitrogenase mechanisms and guides the rational design of novel catalysts.