Zeolite Framework-Anchored Carbon-Doped White Graphene as Antipoisoning Cathode Materials for Proton-Exchange Membrane Fuel Cells

Efficient, robust, and highly sustainable platinum (Pt)-free electrocatalysts are pivotal for advancing the fuel cell (FC) performance. This study introduces a facile and green approach for synthesizing a rationally designed Co-based zeolite imidazole framework (ZIF) anchored onto carbon (C)-doped white graphene (C-WG) as an electrocatalyst (Z@-C-WG) for the oxygen reduction reaction (ORR). The synergistic effects between the ZIF and C-WG yield an electrocatalyst with enriched active sites. The intrinsic dual active sites coupled with favorable physicochemical properties promote oxygen adsorption and enhance the mass transfer rate. The hybrid catalyst demonstrates significantly improved activity, stability, and poisoning resistivity compared to Pt/C. The synthesized electrocatalyst exhibits superior ORR activity with an onset potential of Eon −0.967 V (EonPt/C −0.94 V) in acidic medium and Eon −0.931 V (Eon(Pt/C) −0.919) in alkaline medium. Validation through intrinsic parameters including electrochemical active area (ECSA), active site density (ASD), mass activity (MA), and turnover frequency (TOF) corroborates the catalyst’s enhanced performance. The stability tested for over 35 h coupled with high methanol tolerance affirms the catalyst’s robust activity. The Z@-C-WG electrocatalyst surpasses Pt/C in resisting poisoning species (CO and KSCN); also, poststripping analysis strongly confirms the presence of abundant active centers. Overall, this study offers a unique perspective toward the engineering of ORR catalyst architecture for fuel cell cathode applications.