Thermal expansion coefficient of carbon-supported Pt nanoparticles: In-situ X-ray diffraction study: Thermal expansion coefficient of C-supported Pt nanoparticles

The thermal expansion of carbon-supported Pt nanoparticles with different particle size has been studied in-situ via X-ray diffraction at temperatures from 100 to 300K. The thermal expansion coefficient (TEC) of investigated Pt/C nanoparticles is always superior to that of bulk Pt. When the grain size D decreases from 11 to 3nm, the TEC nonlinearly increases by about 1.66x10(-6)K(-1) which corresponds to a variation of approximate to 20% from bulk Pt. The obtained experimental dependence of TEC for Pt/C nanoparticles has been interpreted using different theoretical approaches. A comparison of the considered models with the experimental data reveals the best agreement from the binding order-length-strength model with the size dependence of TEC experimentally found in carbon-supported Pt nanoparticles.