Zeolite Framework-Anchored\nCarbon-Doped White Graphene\nas Antipoisoning Cathode Materials for Proton-Exchange Membrane Fuel\nCells

Efficient, robust, and highly sustainable platinum (Pt)-free\nelectrocatalysts\nare pivotal for advancing the fuel cell (FC) performance. This study\nintroduces a facile and green approach for synthesizing a rationally\ndesigned Co-based zeolite imidazole framework (ZIF) anchored onto\ncarbon (C)-doped white graphene (C-WG) as an electrocatalyst (Z@-C-WG)\nfor the oxygen reduction reaction (ORR). The synergistic effects between\nthe ZIF and C-WG yield an electrocatalyst with enriched active sites.\nThe intrinsic dual active sites coupled with favorable physicochemical\nproperties promote oxygen adsorption and enhance the mass transfer\nrate. The hybrid catalyst demonstrates significantly improved activity,\nstability, and poisoning resistivity compared to Pt/C. The synthesized\nelectrocatalyst exhibits superior ORR activity with an onset potential\nof <i>E</i><sub>on</sub> −0.967 V (<i>E</i><sub>onPt/C</sub> −0.94 V) in acidic medium and <i>E</i><sub>on</sub> −0.931 V (<i>E</i><sub>on(Pt/C)</sub> −0.919) in alkaline medium. Validation through intrinsic\nparameters including electrochemical active area (ECSA), active site\ndensity (ASD), mass activity (MA), and turnover frequency (TOF) corroborates\nthe catalyst’s enhanced performance. The stability tested for\nover 35 h coupled with high methanol tolerance affirms the catalyst’s\nrobust activity. The Z@-C-WG electrocatalyst surpasses Pt/C in resisting\npoisoning species (CO and KSCN); also, poststripping analysis strongly\nconfirms the presence of abundant active centers. Overall, this study\noffers a unique perspective toward the engineering of ORR catalyst\narchitecture for fuel cell cathode applications.