Predicting the Oxygen-Binding Properties of Platinum Nanoparticle Ensembles by Combining High-Precision Electron Microscopy and Density Functional Theory

Many studies of heterogeneous catalysis, both experimental and computational, make use of idealized structures such as extended surfaces or regular polyhedral nanoparticles. This simplification neglects the morphologicaldiversity in real commercial oxygen reduction reaction (ORR) catalysts used infuel-cell cathodes. Here we introduce an approach that combines 3Dnanoparticle structures obtained from high-throughput high-precision electronmicroscopy with density functional theory. Discrepancies between experimentalobservations and cuboctahedral/truncated-octahedral particles are revealed anddiscussed using a range of widely used descriptors, such as electron-density, d-band centers, and generalized coordination numbers. We use this new approach to determine the optimum particle size for which both detrimental surface roughness and particle shape effects are minimized.