Fe-Co-Ni Ternary Single-Atom Catalysts for Efficient Electrochemical Nitrate Reduction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical nitrate reduction is key for water remediation and ammonia synthesis.
• Single-metal catalysts face limitations in activity and selectivity.
• Developing advanced catalysts is crucial for sustainable chemical processes.

Purpose of the Study:

• To create a novel trimetallic single-atom catalyst for enhanced electrochemical nitrate reduction.
• To investigate the synergistic effects of Fe, Co, and Ni centers.
• To demonstrate the catalyst's application in a zinc-nitrate battery system.

Main Methods:

• Fabrication of atomically dispersed FeCoNi trimetallic single-atom catalyst using a non-equilibrium strategy.
• In-situ experiments and theoretical calculations to analyze catalytic mechanisms.
• Electrochemical testing in a 1 M KOH solution with 100 mM nitrate.
• Integration into a zinc-nitrate battery for simultaneous functions.

Main Results:

• The FeCoNi catalyst achieved 99.4% Faradaic efficiency and a yield rate of 650 µmol h⁻¹ cm⁻².
• Synergistic metal centers stabilized nitric oxide and reduced hydrogenation activation energy.
• The integrated battery demonstrated simultaneous nitrate removal, electricity generation, and ammonia production.

Conclusions:

• The developed trimetallic single-atom catalyst offers a highly efficient route for nitrate valorization and ammonia synthesis.
• The non-equilibrium strategy provides a general approach for designing multi-metal single-atom catalysts.
• This technology holds promise for sustainable water treatment and chemical production.