Yu Rong, Song Hyunjoon, Zhang Xiao-Feng, Yang Peidong
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
J Phys Chem B. 2005 Apr 21;109(15):6940-3. doi: 10.1021/jp050973r.
Thermal stability of facetted Pt nanocrystals on amorphous silica support films was investigated using in situ transmission electron microscopy in a temperature range between 25 and 800 degrees C. The particles started to change their shapes at approximately 350 degrees C. Above 500 degrees C, the particles spread on the support film with increasing temperature, rather than becoming more spherical. Such temperature-induced wetting of Pt nanoparticles on silica surface can be attributed to the interfacial mixing of Pt and SiO(2) and the resulting negative interface energy.
