(665a) Predicting Stability and Charge of Metal Nanoparticles Supported on Amorphous Silica

Rational design and optimization of supported nanoparticle (NP) catalysts requires an accurate description of metal-support interactions because they can significantly impact stability and catalytic activity. We use discrete element method (DEM) simulations to sample the NP-support interface at various NP adsorption locations on recently developed model amorphous silica surface structures. Density functional theory (DFT) calculations reveal that, for various metals, both NP stability and charge depend linearly on the number of NP-silica bonds, which is determined by the surface hydroxyl content, and hence the silica pretreatment temperature. We demonstrate that these correlations are independent of NP geometry and size, and can be calculated using a relatively small number of DFT calculations. As a result, calculated correlations can be used to expedite the prediction of catalyst-support effects for various NP geometries and sizes using only further DEM simulations. Finally, preliminary experimental results validate our prediction relating NP stability to silica pretreatment temperature.