Mesoporous bowl-like carbon support for boosting oxygen transport of fuel cell cathode

The development of advanced support is conducive to promoting the practical application of fuel cells but remains an enormous challenge in terms of stabilizing catalyst particles and enabling improved accessibility to O₂. Beyond solid carbon black and conventional porous carbon, we demonstrate a new type of mesoporous bowl-like carbon support with a high specific surface area of over 1200 m² g^–1 and ~ 4 nm pore. Both rotating disk electrode and membrane electrode assembly (MEA) tests show that BC-supported Pt₃Co (Pt₃Co/BC) catalyst greatly outperforms hollow porous carbon spheres and solid carbon spheres supported Pt₃Co catalysts. The Pt₃Co/BC catalysts exhibited remarkable performance as cathode catalyst in MEA, achieving a comparable open-circuit voltage of approximately 0.95 V under H₂-air condition and a current density of 1.3 A cm^–2 at 0.6 V with a loading of only 0.2 mg_Pt cm^–2. Diffusion simulations and physical characterizations demonstrate that the high porosity and highly accessible pore structure of BC support facilitate the uniform distribution of catalyst particles and enhance the mass transport of O₂, thereby resulting in a significant improvement in catalytic activity and durability. This work provides new insights into the influence of support shape on mass transport of reactants and electrochemical performances of the catalyst in MEA.