Fuel Cell Cathode Pore Structure for ORR Activity

The patent employs a porous conductive carrier with specific pore size distribution (peak pore diameter 2-6 nm) that allows selective access: ionomers can enter larger pores to provide proton transport pathways, while smaller pores remain accessible to oxygen and catalyst active sites. This porous structure resolves the contradiction by creating a hierarchical pore system that accommodates both ionomer coverage for proton transport and exposed catalyst surfaces for ORR activity.

The patent changes the critical parameters of the conductive carrier, specifically the pore size distribution (peak at 2-6 nm) and BET specific surface area (1300-1600 m²/g), to achieve optimal balance. These parameter adjustments create a pore structure that provides sufficient surface area for catalyst dispersion and maintains adequate porosity for water management, thereby enhancing ORR activity while preventing flooding at high current densities.

The patent introduces the porous conductive carrier as an intermediary between the platinum alloy catalyst and the ionomer. The carrier's controlled pore structure mediates the interaction by allowing ionomers to access only specific regions, thereby preventing excessive coverage of the platinum alloy surface while maintaining proton transport. This intermediary structure enables the platinum alloy to express its high ORR activity without the detrimental flooding effects caused by surface functional groups.