(545a) Optimizing the Activity of Oxygen Reduction Reaction Via Structural Engineering of Support for Fe-N-C Electrocatalysts in Proton Exchange Membrane Fuel Cells

The scarcity and costliness of platinum group metals in PEMFC cathodes hinder commercialization. Despite the promise of Fe-N-Cs electrocatalysts as alternatives, their oxygen reduction reaction (ORR) performance falls short. To address this, two carbon support-structural engineering methods were devised. Firstly, defect adjustment in ZIF-NC carbon support, derived from zeolitic imidazolate frameworks, via CO₂ activation. Secondly, the introduction of mesopores into ZIF-NC using the block co-polymer soft-template method. Controlled degree of defect sites in supports enhance intrinsic activity of Fe-N₄ by modifying electronic structure such as charge distribution and spin state. Mesopores aid mass transport, improving active site accessibility. Additionally, the curved surfaces and carbon edge sites generated by mesopores alter the geometric structure of Fe-N₄, optimizing the adsorption energy of oxygen species. Support-structural engineered Fe-N-Cs electrocatalysts exhibit relatively outstanding ORR performance compared to pristine Fe-N-C. MEAs with these electrocatalysts exhibit impressive peak power densities, highlighting their high activity at the MEA level.