Stabilizing Ru Atomic Clusters and Activating Interfacial Water Structure via Bridged p-Block In-N₃O₁ Single Sites...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ruthenium (Ru) atomic clusters (AC) show promise as cost-effective anode catalysts for alkaline hydrogen oxidation reaction (HOR) in anion-exchange-membrane fuel cells (AEMFCs).
• Practical application is hindered by poor structural stability of Ru AC and inefficient proton transport at the electrolyte/electrode interface.

Purpose of the Study:

• To design a novel catalyst system that enhances the stability and proton conductivity for efficient HOR catalysis in AEMFCs.
• To utilize p-block indium single atoms as electronic bridges to stabilize Ru AC and engineer the interfacial proton transport.

Main Methods:

• Synthesis of Ru AC stabilized by indium single atoms with In-N3O1 coordination (Ru AC/In1@CNO).
• Characterization of catalyst structure, electronic properties, and interfacial interactions.
• Electrochemical testing of HOR activity and durability in AEMFCs.

Main Results:

• Strong Ru-In anchoring interactions via d-p orbital hybridization stabilized Ru AC, preventing coalescence and detachment.
• Electronic coupling tuned Ru oxophilicity, promoting hydroxyl coverage and reorienting interfacial water for enhanced proton transport.
• Ru AC/In1@CNO exhibited a mass activity 9.0-fold higher than Pt/C.
• AEMFCs utilizing Ru AC/In1@CNO achieved a peak power density of 1.33 W cm⁻² and stable operation for over 50 hours.

Conclusions:

• Indium single atoms effectively stabilize Ru AC and facilitate proton transport through a reconstructed hydrogen-bond network.
• The developed Ru AC/In1@CNO catalyst offers superior performance and durability for HOR catalysis in AEMFCs.
• This strategy provides a pathway for developing advanced catalysts for next-generation fuel cells.