Lattice Strain Mapping of Platinum Nanoparticles on Carbon and SnO2 Supports.
It is extremely important to understand the properties of supported metal nanoparticles at the atomic scale. In particular, visualizing the interaction between nanoparticle and support, as well as the strain distribution within the particle is highly desirable. Lattice strain can affect catalytic activity, and therefore strain engineering via e.g. synthesis of core-shell nanoparticles or compositional segregation has been intensively studied. However, substrate-induced lattice strain has yet to be visualized directly. In this study, platinum nanoparticles decorated on graphitized carbon or tin oxide supports are investigated using spherical aberration-corrected scanning transmission electron microscopy (Cs-corrected STEM) coupled with geometric phase analysis (GPA). Local changes in lattice parameter are observed within the Pt nanoparticles and the strain distribution is mapped. This reveals that Pt nanoparticles on SnO2 are more highly strained than on carbon, especially in the region of atomic steps in the SnO2 lattice. These substrate-induced strain effects are also reproduced in density functional theory simulations, and related to catalytic oxygen reduction reaction activity. This study suggests that tailoring the catalytic activity of electrocatalyst nanoparticles via the strong metal-support interaction (SMSI) is possible. This technique also provides an experimental platform for improving our understanding of nanoparticles at the atomic scale.
1] International Research Center for Hydrogen Energy, Kyushu University, Fukuoka 819-0395, Japan [2] Next-Generation Fuel Cell Research Center (NEXT-FC), Kyushu University, Fukuoka 819-0395, Japan [3] Faculty of Engineering, Department of Hydrogen Energy Systems, Kyushu University, Fukuoka 819-0395, Japan.
Takeshi
T
Daio
International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.
Aleksandar
A
Staykov
International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.
Limin
L
Guo
International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.
Jianfeng
J
Liu
Faculty of Engineering, Department of Materials Science and Engineering, Kyushu University, Fukuoka 819-0395, Japan.
Masaki
M
Tanaka
International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.
Stephen Matthew
SM
Lyth
1] International Research Center for Hydrogen Energy, Kyushu University, Fukuoka 819-0395, Japan [2] Next-Generation Fuel Cell Research Center (NEXT-FC), Kyushu University, Fukuoka 819-0395, Japan [3] Faculty of Engineering, Department of Hydrogen Energy Systems, Kyushu University, Fukuoka 819-0395, Japan [4] International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.
Kazunari
K
Sasaki