Oxygen Reduction at Shape‐Controlled Platinum Nanoparticles and Composite Catalysts Based on (100)Pt Nanocubes on Microporous–Mesoporous Carbon Supports

The electrochemical oxygen reduction reaction (ORR) on bare (100)Pt nanoparticles supported by molybdenum‐carbide‐derived carbon [(100)Pt–C(Mo2C)] with high specific surface area and controlled microporosity–mesoporosity, pore size distribution, electrical conductivity, and corrosion stability was studied in 0.5 M H2SO4 solution by using rotating‐disk‐electrode and cyclic voltammetry methods. The C(Mo2C) powder was prepared from Mo2C at a fixed chlorination temperature (750 °C). Pt nanoparticles were prepared through colloid chemistry and deposited onto/into C(Mo2C) and Vulcan XC72 carbon supports for comparison. The ORR cathodic current densities and half‐wave potentials strongly depend on the characteristics of the carbon material used as the support. High values for the ORR current density were calculated for (100)Pt–C(Mo2C) and the half‐wave potential is nearly 80 mV more positive compared with that for the (100)Pt–Vulcan XC72 catalyst with a similar catalyst loading.