Templated N‐Doped Carbon Nanospheres with Tailored Porosity for High Performance PEM Fuel Cell Catalysts Under a Wide Range of Conditions

Abstract Recent studies have shown the importance of porous carbon supports in achieving high‐performance proton exchange membrane fuel cells (PEMFCs). Porous carbon supports control the cascaded oxygen and proton mass transport through the intraparticle porosity inside the electrocatalyst and through the interparticle porosity throughout the electrode. Here, two monodisperse mesoporous (10 and 28 nm pore size) N‐doped carbon (MPNC) nanosphere supports with large particle sizes (>100 nm) are presented as supports for the design of advanced Pt‐based PEMFC cathode electrocatalysts. The morphology and structure of the MPNC nanosphere supports and derived catalysts enable a 3D bottom‐up design of the catalyst layer in terms of intra‐ and interparticle porosities, thereby positively impacting the fuel cell performance. Characterization at rotating disc electrode (RDE) and PEMFC single‐cell level reveals the strong potential of the MPNC as catalyst support materials, combining excellent oxygen transport properties and improved mass activities. The MPNC‐based catalysts achieve 0.66 W cm −2 at 0.76 V in single‐cell configuration, outperforming state‐of‐the‐art reference catalyst material by 27%. The results confirm not only the advantages of mesoporous N‐doped carbons as advanced catalyst supports but also highlight the underexplored potential of tailoring performance determining parameters of the carbon support such as pore size and particle size.