Abstract
Bimetallic nanocrystals with a core@shell architecture are versatile, multifunctional particles. The lattice mismatch between core and shell regions induces strain, affecting the electronic properties of the shell metal, which is important for applications in catalysis. Here, we analyze this strain in core@shell nanocubes as a function of lattice mismatch and shell thickness. Coupling geometric phase analysis from atomic resolution scanning transmission electron microscopy images with molecular dynamics simulations reveals lattice relaxation in the shell within only a few monolayers and an overexpansion in the axial direction. Interestingly, many works report core@shell metal nanocatalysts with optimum performance at greater shell thicknesses. Our findings suggest that not strain alone but secondary factors, such as structural defects or structural changes in operando, may account for observed enhancements in some strain-engineered nanocatalysts; e.g., Rh@Pt nanocubes for formic acid electrooxidation.
| Original language | English |
|---|---|
| Pages (from-to) | 1105-1114 |
| Number of pages | 10 |
| Journal | Nanoscale Advances |
| Volume | 2 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2020 |
Funding
S. E. S, J. T. L. G.; K. M. K. acknowledge nancial support from Indiana University and U.S. DOE BES Award DE-SC0018961. We also want to thank the IU Electron Microscopy Center and Nanoscale Characterization Facility for access to the necessary instrumentation. A. L. and M. E. acknowledge funding from Deutsche Forschungsgemeinscha through the Cluster of Excellence Engineering of Advanced Materials (EXC 315/2). Supercomputer time for this research was supported in part by the Lilly Endowment, Inc., through its support for the Indiana University Pervasive Technology Institute, and in part by the Indiana META Cyt Initiative. The Indiana META Cyt Initiative at IU was also supported in part by the Lilly Endowment, Inc. A portion of the electron microscopy characterization was conducted as part of a user proposal at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences, a U.S. Department of Energy Office of Science User Facility. S. E. S, J. T. L. G.; K. M. K. acknowledge financial support from Indiana University and U.S. DOE BES Award DE-SC0018961. We also want to thank the IU Electron Microscopy Center and Nanoscale Characterization Facility for access to the necessary instrumentation. A. L. and M. E. acknowledge funding from Deutsche Forschungsgemeinschaft through the Cluster of Excellence Engineering of Advanced Materials (EXC 315/2). Supercomputer time for this research was supported in part by the Lilly Endowment, Inc., through its support for the Indiana University Pervasive Technology Institute, and in part by the Indiana META Cyt Initiative. The Indiana META Cyt Initiative at IU was also supported in part by the Lilly Endowment, Inc. A portion of the electron microscopy characterization was conducted as part of a user proposal at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences, a U.S. Department of Energy Office of Science User Facility.
| Funders | Funder number |
|---|---|
| Indiana University Pervasive Technology Institute | |
| Lilly Endowment, Inc. | |
| META Cyt Initiative | |
| Oak Ridge National Laboratory | |
| U.S. DOE BES | DE-SC0018961 |
| U.S. Department of Energy Office of Science | |
| Indiana University | |
| Lilly Endowment | |
| Deutsche Forschungsgemeinschaft | EXC 315/2 |