Abstract
Conformal deposition of platinum as ultrathin shells on facet-controlled palladium nanocrystals offers a great opportunity to enhance the catalytic performance while reducing its loading. Here we report such a system based on palladium icosahedra. Owing to lateral confinement imposed by twin boundaries and thus vertical relaxation only, the platinum overlayers evolve into a corrugated structure under compressive strain. For the core-shell nanocrystals with an average of 2.7 platinum overlayers, their specific and platinum mass activities towards oxygen reduction are enhanced by eight- And sevenfold, respectively, relative to a commercial catalyst. Density functional theory calculations indicate that the enhancement can be attributed to the weakened binding of hydroxyl to the compressed platinum surface supported on palladium. After 10,000 testing cycles, the mass activity of the core-shell nanocrystals is still four times higher than the commercial catalyst. These results demonstrate an effective approach to the development of electrocatalysts with greatly enhanced activity and durability.
| Original language | English |
|---|---|
| Article number | 7594 |
| Journal | Nature Communications |
| Volume | 6 |
| DOIs | |
| State | Published - 2015 |
Bibliographical note
Publisher Copyright:© 2015 MacMillan Publishers Limited. All rights reserved.
Funding
The syntheses were supported by start-up funds from the Georgia Institute of Technology (to Y.X.) while the computations were supported by DOE-BES (Office of Chemical Scienses, grant DE-FG02-05ER15731, to M.M.). As visiting students, X.W., M.L. and L.Z. were also partially supported by the China Scholarship Council. Part of the electron microscopy work was performed through a user project supported by the ORNL’s Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. J.L. gratefully acknowledges the support by Arizona State University and the use of facilities in the John M. Cowley Center for High Resolution Electron Microscopy at Arizona State University. The calculations were performed at supercomputing centres located at EMSL (which is sponsored by the DOE Office of Biological and Environmental Research at PNNL), CNM (supported by DOE contract DE-AC02-06CH11357 to ANL) and NERSC (supported by DOE contract DE-AC02-05CH11231 to LBL).
| Funders | Funder number |
|---|---|
| DOE-BES | |
| ORNL’s Center for Nanophase Materials Sciences | |
| Office of Chemical Scienses | DE-FG02-05ER15731 |
| U.S. Department of Energy | DE-AC02-05CH11231, DE-AC02-06CH11357 |
| Office of Science | |
| Biological and Environmental Research | |
| Georgia Institute of Technology | |
| Arizona State University | |
| Pacific Northwest National Laboratory | |
| China Scholarship Council |