A Simple Descriptor toward Optimizing Electrocatalytic N₂ Oxidation to HNO₃ Performance over Graphene-Based...

Area of Science:

• Catalysis
• Materials Science
• Electrochemistry

Background:

• Single-atom catalysts (SACs) offer advantages for electrochemical N2 oxidation reactions (EN2OR) to produce HNO3.
• Developing efficient EN2OR SACs and screening methods remains a challenge.

Purpose of the Study:

• To propose a simple descriptor for evaluating and screening EN2OR SACs.
• To accelerate the discovery of high-performance SACs for EN2OR.

Main Methods:

• Constructed surface reaction phase diagrams for pyridinic nitrogen-doped graphene-supported SACs.
• Developed a descriptor based on geometric and atomic properties (d electron number, electronegativity, coordinate number).
• Performed high-throughput screening of 160 candidate SACs and validated with DFT calculations.

Main Results:

• The descriptor accurately predicts EN2OR activity and selectivity, independent of DFT simulations.
• 13 high-performance SAC candidates with <1.0 V overpotential were identified.
• Screened CoO2N2-G and RhO2N2-G SACs showed superior EN2OR performance (0.64 and 0.68 V overpotential).

Conclusions:

• The proposed descriptor enables rapid and reliable screening of EN2OR SACs.
• This approach facilitates the discovery of advanced catalysts for sustainable nitric acid synthesis.
• Identified CoO2N2-G and RhO2N2-G as promising candidates for EN2OR applications.