P-Doping Strategy Increasing the Durability of PtCo Nanoparticles for the Oxygen Reduction Reaction

Highlyactive and durable electrocatalysts for the cathodic oxygenreduction reaction (ORR) are vital for the large-scale commercializationof proton exchange membrane fuel cells. Alloying Pt with transitionmetals is a promising method to enhance the ORR catalytic activity,but the leaching of transition metals is inevitable, which deterioratesthe stability. Here, we report the design of a P-doped PtCo electrocatalystsupported on carbon via a facile one-pot hydrothermal method. On theone hand, the introduction of P into the carbon support by phyticacid can enhance the anchoring ability of the PtCo alloy and inhibitthe migration of nanoparticles. On the other hand, the doping of Pinto the lattice of the PtCo alloy further tunes the electronic effect,which improves activity and stability simultaneously. The mass activityof as-prepared P-5-PtCo/C at 0.9 V can reach 0.72 A mg(Pt) (-1), which is 4.5 times higher than thatof commercial Pt/C. After an accelerated durability test (ADT) of30,000 potential cycles, the mass activity only decreased by 9.4%.Meanwhile, the average particle size of the catalyst slightly increasedfrom 4.94 to 5.15 nm after the ADT of 70,000 potential cycles. Thisstudy provides a facile approach for constructing nonmetal-doped PtMcatalysts with improved durability for the ORR. Highly active and durable electrocatalystsfor the cathodicoxygen reduction reaction are vital for the large-scale commercializationof proton exchange membrane fuel cells.