P-Doping Strategy Increasing the Durability of PtCo Nanoparticles for the Oxygen Reduction Reaction
Jun‐Fei Shen, Sheng-Nan Hu, Na Tian, Mengying Li, Shuangli Yang, Si‐Yi Tian, Mingshu Chen, Zhi‐You Zhou, Shi‐Gang Sun
Abstract
Highly active and durable electrocatalysts for the cathodic oxygen reduction reaction (ORR) are vital for the large-scale commercialization of proton exchange membrane fuel cells. Alloying Pt with transition metals is a promising method to enhance the ORR catalytic activity, but the leaching of transition metals is inevitable, which deteriorates the stability. Here, we report the design of a P-doped PtCo electrocatalyst supported on carbon via a facile one-pot hydrothermal method. On the one hand, the introduction of P into the carbon support by phytic acid can enhance the anchoring ability of the PtCo alloy and inhibit the migration of nanoparticles. On the other hand, the doping of P into the lattice of the PtCo alloy further tunes the electronic effect, which improves activity and stability simultaneously. The mass activity of 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 that of commercial Pt/C. After an accelerated durability test (ADT) of 30,000 potential cycles, the mass activity only decreased by 9.4%. Meanwhile, the average particle size of the catalyst slightly increased from 4.94 to 5.15 nm after the ADT of 70,000 potential cycles. This study provides a facile approach for constructing nonmetal-doped PtM catalysts with improved durability for the ORR.