biostudies-literatureIslam MNAlberta InnovatesCanada Foundation for Innovation (Fondation canadienne pour l'innovation)6157https://www.ebi.ac.uk/biostudies/studies/S-EPMC9579166biostudies-literatureUnknown13(1)The development of low-Platinum content polymer electrolyte fuel cells (PEFCs) has been hindered by inexplicable reduction of oxygen reduction reaction (ORR) activity and unexpected O₂ mass transport resistance when catalysts have been interfaced with ionomer in a cathode catalyst layer. In this study, we introduce a bottom-up designed spherical carbon support with intrinsic Nitrogen-doping that permits uniform dispersion of Pt catalyst, which reproducibly exhibits high ORR mass activity of 638 ± 68 mA mg_Pt^-1 at 0.9 V and 100% relative humidity (RH) in a membrane electrode assembly. The uniformly distributed Nitrogen-functional surface groups on the carbon support surface promote high ionomer coverage directly evidenced by high-resolution electron microscopNature communicationsDesigning fuel cell catalyst support for superior catalytic activity and low mass-transport resistance.PMC957916631936202102615Mansoor Basha ABKollath VOJankovic JIslam MNKaran KSoleymani APfalseDesigning fuel cell catalyst support for superior catalytic activity and low mass-transport resistance.The development of low-Platinum content polymer electrolyte fuel cells (PEFCs) has been hindered by inexplicable reduction of oxygen reduction reaction (ORR) activity and unexpected O₂ mass transport resistance when catalysts have been interfaced with ionomer in a cathode catalyst layer. In this study, we introduce a bottom-up designed spherical carbon support with intrinsic Nitrogen-doping that permits uniform dispersion of Pt catalyst, which reproducibly exhibits high ORR mass activity of 638 ± 68 mA mg_Pt^-1 at 0.9 V and 100% relative humidity (RH) in a membrane electrode assembly. The uniformly distributed Nitrogen-functional surface groups on the carbon support surface promote high ionomer coverage directly evidenced by high-resolution electron microscop2022-01-01T00:00:00Z2022 Oct2025-04-19T21:19:53.115Z2025-04-19T21:19:53.115ZS-EPMC95791663625799210.1038/s41467-022-33892-8