Elucidating the mechanistic synergy of fluorine and oxygen doping in boosting platinum-based catalysts for proton exchange membrane fuel cells.

Proton exchange membrane fuel cells (PEMFCs) are recognized as promising next-generation energy sources for automotive applications. The development of efficient, durable, and low-cost electrocatalysts to enhance the oxygen reduction reaction (ORR) kinetics is crucial. Herein, we report the synthesis of Pt@C/F-COOH catalysts via the pyrolysis and HNO oxidation of the carbon support, followed by the growth of Pt nanoparticles through reduction. These catalysts demonstrate superior ORR activity with an increased half-wave potential (E) by 70 mV compared to commercial Pt/C. Durability tests reveal that Pt@C/F-COOH catalysts exhibit only 1 % decay after 50,000 s, significantly lower than the 52 % decay observed for commercial Pt/C, outperforming most reported Pt-based catalysts. Theoretical calculations indicated that the interaction between the CF groups and the Pt nanoparticles leads to a unique electron redistribution, resulting in more positively charged Pt sites and optimized desorption of the reaction intermediates. Additionally, the exceptional durability is attributed to the appropriate degree of oxidation of the carbon support, yielding a high number of defect sites and optimal graphitization, enhancing Pt anchoring and antioxidant capacity.