Binuclear Metal Phthalocyanines with Enhanced Activity in the Oxygen Evolution Reaction: A First-Principles Study

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Efficient catalysts are vital for the oxygen evolution reaction (OER).
• Understanding OER mechanisms is key to catalyst design.
• Metal phthalocyanines (MPc) are potential OER catalysts.

Purpose of the Study:

• Investigate alkaline OER mechanisms on mononuclear (MPc) and binuclear (bi-MPc) metal phthalocyanines.
• Evaluate the stability and activity of FePc and bi-CoPc.
• Analyze the role of macrocyclic ligands in OER catalysis.

Main Methods:

• Density functional theory (DFT) calculations.
• Electronic structure analysis.
• Thermodynamic evaluation of metal leaching and overpotentials.

Main Results:

• FePc and bi-CoPc show enhanced stability and OER activity.
• Metal leaching energies for FePc and bi-CoPc are 2.28 and 2.45 eV.
• OER overpotentials for FePc and bi-CoPc are 0.48 and 0.57 V.
• Binuclear MPc stabilizes intermediates via hole reservoirs and charge dispersal.

Conclusions:

• Macrocyclic ligands play a significant role in the rate-determining step of OER.
• Electronic structure and ligand effects are crucial for designing active and stable OER catalysts.
• DFT provides valuable insights into OER mechanisms on metal phthalocyanines.