Francesca Baletto (KCL)
Size and shape dependence of activity of metallic nanoparticles
In this talk I will present the implementation of a novel multiscale approach to predict on-the-fly how isomer fluxionality of metallic nanoparticles affect their catalytic properties. We adapt a version of the computational hydrogen electrode model to take full benefit of nanogenomics - an unique classification of the adsorption sites based on a geometrical descriptor. This approach allows a fast high-throughput analysis of the catalytic properties of several isomers and of different samples at finite temperature over a wide size range.
With a focus on Pt-nanoparticles for the electrochemical reduction of molecular oxygen, we show that the morphological control of individual nanoparticles is mandatory, up to diameters of 5 nm, at least. Surprisingly, spherical but amorphous isomers are found to be the most active above 3 nm, while defected and concave polyhedra activity peaks around 2-3 nm. Furthermore, we show that the activity of size-selected samples can be explained as a function of the distribution of isomers within the specimen, opening a new strategy of design metallic electrodes