Stability of Porous Platinum Nanoparticles: Combined In Situ TEM and Theoretical Study

Chang, S.L.Y., A.S. Barnard, C. Dwyer, T.W. Hansen, J.B. Wagner, R.E. Dunin- Borkowski, H. Xu, et al., 2012

Image courtesy of J. Phys. Chem. Lett.

Abstract

Porous platinum nanoparticles provide a route for the development of catalysts that use less platinum without sacrificing catalytic performance. Here, we examine porous platinum nanoparticles using a combination of in situ transmission electron microscopy and calculations based on a first-principles-parametrized thermodynamic model. Our experimental observations show that the initially irregular morphologies of the as-sythesized porous nanoparticles undergo changes at high temperatures to morphologies having faceted external surfaces with voids present in the interior of the particles. The increasing size of stable voids with increasing temperature, as predicted by the theoretical calculations, shows excellent agreement with the experimental findings. The results indicate that hollow-structured nanoparticles with an appropriate void-to-total-volume ratio can be stable at high temperatures.

Impact Statement

This paper explores the thermal stability of nanoporous Pt as a function of temperature. Pt is used as a catalyst material, and it is thought that it is more active with increasing surface area, but porous particles must be stable at elevated temperatures for use in real world applications. The TEM used was an FEI Titan.