Theoretical Investigation of Metal-Support Interactions on Ripening Kinetics of Supported Particles

The stability of supported metal particles is one of the key issues for successful industrialization of catalysts. A theoretical study of Ostwald ripening of supported particles and its dependence on metal-support interactions, sublimation energy, and surface energy is reported. Two distinct metal-support interactions are differentiated: metal particle-support and metal atom-support. Although strong metal particle-support interaction (small contact angle) stabilizes the supported particles and improve the ripening resistance, strong metal atom-support interactions decrease the total activation energy and dramatically lower the onset temperature and half-life time of ripening, a fact that should be prevented. Moreover, supported particles with low surface energy and/or high sublimation energy of supported particles would have a high onset temperature and a long half-life time. Compared to the metal particle-support interaction and surface energy, the metal atom-support interaction and sublimation energy are most influential to the overall ripening resistance. The present work highlights the importance of interplay between two types of metal-support interactions on the overall stability of supported particles.