Incorporation of Activated Biomasses in Fe-N-C Catalysts for Oxygen Reduction Reaction with Enhanced Stability in Acidic Media

Fe-N-C materials are promising oxygen reduction reaction (ORR) catalysts for replacing expensive platinum-based (Pt/C) in proton exchange membrane fuel cells. However, they still show low volumetric activity and stability compared to Pt/C catalysts, with carbon corrosion being one of the main factors loss active Fe-Nx sites. Within this study, phosphoric acid-activated rye straw coconut shells revealed as a matrix sites advanced against electrochemical (5000 cycles, 1.0–1.5 VRHE, 0.1 M HClO4) common catalyst based on black. Electrochemical characterization two biomass-based (Fe-N-CBio) shows hand 50% higher terms mass well comparable site density but other lower selectivity toward four-electron ORR than catalyst. Nitrite stripping experiments acetate buffer an electrolyte display 1.5-fold stronger effect carboxylic acid adsorption catalyst, revealing differences electronic structure Fe-N-CBio This difference is mainly attributed presence phosphor species amounts nitrogen functionalities catalysts. The P assumed stabilize by inhibiting electron withdrawal from C. study points out impact further application activated biomasses more stable sustainable ORR.