Second-shell modulation on porphyrin-like Pt single atom catalysts for boosting oxygen reduction reaction

Area of Science:

• Heterogeneous Catalysis
• Materials Science
• Electrochemistry

Background:

• The first coordination shell is critical for single-atom catalyst (SAC) performance.
• The role of the second coordination shell in SACs has been largely unexplored.
• Understanding coordination shell effects is key to designing advanced catalysts.

Purpose of the Study:

• To investigate the impact of second coordination shell modification on SACs.
• To develop a post-doping strategy for controlled second coordination shell engineering.
• To enhance the intrinsic activity and stability of platinum-based SACs.

Main Methods:

• Post-doping strategy to incorporate phosphorus (P) into the second coordination shell of a porphyrin-like platinum (Pt) SAC.
• Characterization of the electronic structure and adsorption properties of the modified catalyst.
• Electrocatalytic performance evaluation in both alkaline and acidic media.

Main Results:

• Incorporation of P into the second coordination shell increased the charge density at the Fermi level of the Pt single atom.
• The P atom enhanced adsorption of large anions (ClO4-), preventing Pt site poisoning in acidic conditions.
• The Pt-N4P-C catalyst demonstrated significantly higher activity and stability compared to the Pt-N4-C catalyst and commercial Pt/C.

Conclusions:

• Second coordination shell modulation is a powerful strategy for optimizing SAC performance.
• The developed post-doping method allows for predictable and controlled catalyst design.
• This approach offers a pathway to highly active and stable SACs for diverse electrochemical applications.