Patchy Fe-N-C supported low-loading Pt nanoparticles as a highly active cathode for proton exchange membrane fuel cells

Abstract

The high cost and unfavorable catalytic performance for oxygen reduction reaction (ORR) is one of the crucial obstacles that impede widely commercialization of proton-exchange membrane fuel cells (PEMFCs). Herein, we provide a novel, mass-producible ORR catalyst made of low-loading (10 wt%) Pt nanoparticles bound to patchy nitrogen-doped carbon (PNC) with uniformly dispersed FeN4 sites (Pt/FeN4-PNC). The derived catalyst exhibits significantly improved catalytic activity and stability, obtaining a promising mass activity (MA) of 0.94 A mgpt−1 at 0.9 V (vs. RHE) with a negligible decay after 30,000 cycles accelerated durability test (ADT). In the fuel-cell assessment (under H2-Air conditions at 80 ℃), the Pt/FeN4-PNC and Pt/FeN4-PNC-10 g (scaled-up production) achieved peak power densities of 1.13 W cm−2 and 1.14 W cm−2, respectively, and retained 88.5 % and 88.1 % of the initial values after 30,000 voltage cycles (0.60–0.95 V). The patchy structure of PNC substrate guarantees fast electron routes and resistance to corrosion. With the FeN4 active sites in the PNC substrate, the oxygen molecules are concurrently reduced on the surfaces of the carbon substrate and Pt nanoparticles, thereby causing the ORR reaction zone on the catalyst layer to expand.