A new strategy for enhancing the oxygen reduction reaction (ORR) activity of carbon-based catalysts in acidic media is proposed and characterized; the strategy consists in modifying the ORR through dual doping of nitrogen and phosphorus into the carbon. The P, N-doped carbon is prepared via pyrolysis of a mixture composed of dicyandiamide (DCDA), phosphoric acid, cobalt chloride, and iron chloride at 900 C under an Ar atmosphere. The P-doping induces an uneven surface with many open edged sites

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... in the carbon morphology and increases the carbon surface area from 108.1 to 578.8 m 2 g À1 . The XRD, XPS-C 1s , and Raman spectroscopy results reveal that the crystallinity and degree of the sp 2 -carbon network decrease and the number of defect sites of the carbon increase as the amount of P-doping increases. All catalysts demonstrated similar proportions of N-doping types regardless of the P-doping amount: pyridinic-N and graphitic-N were dominant phases in the carbon lattice. In the ORR, the onset potential of the prepared catalysts was 0.6 V (vs. Ag/AgCl) in 1 M HClO 4 . The N-doped carbon records À0.69 mA mg À1 of mass activity at 0.5 V (vs. Ag/AgCl), but additional P-doping results in an increase of activity (À2.88 mA mg À1 ) that is more than fourfold that produced without the additional Pdoping. Moreover, additional P-doping also modifies the ORR pathway, as the N-doped carbon induces more than 10% of H 2 O 2 ; however, the P, N-doped carbon produced below 4% of H 2 O 2 during the ORR.