Synergy of porous network nanostructuring and nonmetallic phosphorus alloying for efficient oxygen reduction of platinum

Abstract

Alloying of nanostructured platinum (Pt)-based electrocatalysts can significantly improve their electrocatalytic performance for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). However, there are few studies of nonmetals alloyed Pt-based nanostructures for ORR electrocatalysis. Herein, we present a synergy of porous network nanostructuring and nonmetallic phosphorus (P) alloying to engineer the high-performance P-alloyed Pt nanospheres (P-PtNSs) for efficient ORR electrocatalysis. This characteristic porous network nanostructure is crafted through surfactant soft-templates induced confinement growth, and P-alloying is realized by a post-phosphating method. The introduction of P into Pt lattice can not only regulate electronic and geometric structure but also augment electrocatalytic active sites through the contribution of Pt-P bonds. The resultant P-PtNSs/C catalyst shows mass activity and specific activity at 0.90 V, surpassing those of commercial Pt/C catalyst by factors of 2.7 and 5.8, respectively, while also exhibiting superior stability. More importantly, the H2-O2 PEMFC with a P-PtNSs/C cathode exhibits higher current and power densities than one with Pt/C throughout the entire evaluation process, achieving a peak power density of 1.28 W cm−2 at a low Pt loading of 0.1 mgPt cm−2. This study will provide valuable insights into the nonmetals alloying and nanostructuring of Pt-based ORR electrocatalysts.