Supported nanoparticles play a key role in a wide-ranging implications in health, information, energy, and many other fields where there is a major economic benefit in the commercialization of new technologies.[1,2] The... [ view full abstract ]
Supported nanoparticles play a key role in a wide-ranging implications in health, information, energy, and many other fields where there is a major economic benefit in the commercialization of new technologies.[1,2] The activity and selectivity of the catalysts are highly dependent on the size and shape of the metal nanoparticles. However, the catalysts are deactivated under reaction conditions, mainly due to to the sintering process leading to the formation of larger and less active particles. The major mechanism for the particles’ sintering is Ostwald ripening (Fig 1a), which is the merging of small clusters or single adatoms with larger clusters, and the migration and coalescence (Fig 1b) of larger clusters. Especially, the loss of very small and often highly active clusters at the early stage of the sintering process is mainly caused by Ostwald ripening.[3]
In the presented study, we use dispersion-corrected density functional theory to evaluate the structure and growth of gold nanoparticles on different supports from first principles. Using the Vienna ab initio simulation package (VASP), the structures of Aun clusters (n = 1-20) on MgO (001), CeO2 (111), and graphite (001) model surfaces were investigated. Moreover, the mobility of gold adatoms and their coalescence with larger clusters according to the Ostwald ripening mechanism was studied. Hence, the presented results give a comprehensive insight into the influence of the support material on the structure, mobility and growth of supported gold clusters.
References:
[1] J. A. Anderson, J. A. Anderson, M. Fernández-Garcia, Supported Metals in Catalysis, Imperial College Press, 2005.
[2] A. Wieckowski, E. R. Savinova, C. G. Vayenas, Catalysis and electrocatalysis at nanoparticle surfaces, CRC Press, 2003.
[3] T. W. Hansen, A. T. DeLaRiva, S. R. Challa, A. K. Datye, Acc. Chem. Res. 2013, 46, 1720–1730.
