[2D12-21] Surface Science (SS1) Physical Property

3:15 PM - 3:30 PM JST(6:15 AM - 6:30 AM UTC)

[2D15] Interfacial distribution of ionomers on nitrogen-doped carbon model catalyst and its impact on catalytic activity

*Kaito Homma¹, Yuri kasagi¹, kenji hayashida², Satoru Takakusagi^1,2, Kotaro Takeyasu^1,2 (1. Graduate School of Environmental Science, Hokkaido University (Japan), 2. Institute for Catalysis, Hokkaido University (Japan))

Solid electrolyte–catalyst interfaces are crucial reaction sites that dictate the activity and durability of next-generation electrochemical devices, such as polymer electrolyte fuel cells (PEFCs) and solid-state batteries. This study establishes an interface design guideline for the multiphase boundary in fuel cell reactions. Utilizing a nitrogen-doped HOPG model catalyst with single-atom active sites, we evaluated ORR activity at a solid electrolyte interface. AFM imaging after casting ionomer revealed that it preferentially accumulated on terrace planes, leaving active step edges sharply exposed. Evaluation in a solid-state cell revealed a volcano-shaped dependency of ORR activity on ionomer loading. Optimal loading creates efficient proton pathways, whereas excessive loading forms a thick layer that hinders local oxygen diffusion. Consequently, next-generation catalyst layers require a localized interfacial molecular design to prevent excessive ionomer adsorption at active edge sites.

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