Single Iridium Atom Doped Ni₂P Catalyst for Optimal Oxygen Evolution.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Single-atom catalysts (SACs) offer 100% active sites for oxygen evolution reaction (OER).
• Enhancing OER catalytic activity and stability in SACs, especially with overpotentials below 180 mV, remains a significant challenge.

Purpose of the Study:

• To develop a highly active and stable single-atom catalyst for the oxygen evolution reaction (OER).
• To investigate the structural and electronic properties influencing the catalytic performance of single-atom catalysts.

Main Methods:

• Synthesis of iridium single atom on Ni2P catalyst (IrSA-Ni2P).
• Electrochemical characterization of OER performance, including overpotential and current density measurements.
• Computational simulations (e.g., DFT) to understand active site structure and reaction mechanisms.

Main Results:

• IrSA-Ni2P achieved a record low overpotential of 149 mV at 10 mA·cm−2 in 1.0 M KOH.
• The catalyst exhibited approximately 28-fold higher current density compared to IrO2 at 1.53 V vs RHE.
• Experimental and computational studies confirmed Ir single atoms on Ni sites, with a reconstructed Ir-O-P/Ni-O-P bonding environment crucial for OER activity.

Conclusions:

• The IrSA-Ni2P catalyst demonstrates exceptional OER activity and stability.
• The unique electronic structure and reconstructed bonding environment are key to enhanced catalytic performance.
• This work provides a new strategy for designing efficient SACs for OER and other electrochemical reactions.