Abstract
Owing to the presence of {111} facets, twin boundaries, and strain fields on the surface, noble-metal nanocrystals with an icosahedral shape have been reported with stellar performance toward an array of catalytic reactions. Here, we report the successful synthesis of Ru icosahedral nanocages with a face-centered cubic (fcc) structure by conformally coating Pd icosahedral seeds with ultrathin Ru shells, followed by selective removal of the Pd cores via chemical etching. We discovered that the presence of bromide ions was critical to the layer-by-layer deposition of Ru atoms. According to in situ XRD, the fcc structure in the Ru nanocages could be retained up to 300 °C before it was transformed into the conventional hexagonal close-packed (hcp) structure. Additionally, the icosahedral shape of the Ru nanocages could be largely preserved up to 300 °C. The Ru icosahedral nanocages with twin boundaries on the surface exhibited greatly enhanced activities toward both the reduction of 4-nitrophenol and decomposition of hydrazine than their cubic and octahedral counterparts. When benchmarked against the parental Pd@Ru core-shell nanocrystals, all the Ru nanocages displayed superior catalytic activities. First-principles density functional theory calculations also suggest that the fcc-Ru icosahedral nanocages containing residual Pd atoms are more promising than the conventional hcp-Ru solid nanoparticles in catalyzing nitrogen reduction for ammonia synthesis. With the subsurface impurities of Pd, the twin boundary regions of the icosahedral nanocages are able to stabilize the N2 dissociation transition state, reducing the overall reaction barrier and promoting the competition with the N2 desorption process.
| Original language | English |
|---|---|
| Pages (from-to) | 6948-6960 |
| Number of pages | 13 |
| Journal | ACS Catalysis |
| Volume | 8 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 3 2018 |
Funding
This work was supported by a grant from the Department of Energy-Basic Energy Sciences, Division of Chemical Sciences (DE-FG02-05ER15731) and start-up funds from the Georgia Institute of Technology. High-resolution imaging was performed at the Georgia Institute of Technology’s Institute of Electronics and Nanotechnology (IEN) facilities and the Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences, which is a U.S. DOE Office of Science User Facility (M.C.). The DFT calculations were performed at supercomputing centers located at EMSL, which is sponsored by the DOE Office of Biological and Environmental Research at PNNL; CNM at ANL, supported by DOE contract DE-AC02- 06CH11357; NERSC, supported by DOE contract DE-AC02-05CH11231; and UW-Madison Center for High Throughput Computing (CHTC), supported by UW-Madison, the Advanced Computing Initiative, the Wisconsin Alumni Research Foundation, the Wisconsin Institutes for Discovery, and the National Science Foundation, and is an active member of the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy’s Office of Science. A portion of this research was completed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. Z.D.H. gratefully acknowledges support from the National Science Foundation Graduate Research Fellowship under Grant DGE-1650044 and the Georgia Tech-ORNL Fellowship. This work was supported by a grant from the Department of Energy-Basic Energy Sciences, Division of Chemical Sciences (DE-FG02-05ER15731) and start-up funds from the Georgia Institute of Technology. High-resolution imaging was performed at the Georgia Institute of Technology's Institute of Electronics and Nanotechnology (IEN) facilities and the Oak Ridge National Laboratory's Center for Nanophase Materials Sciences, which is a U.S. DOE Office of Science User Facility (M.C.). The DFT calculations were performed at supercomputing centers located at EMSL, which is sponsored by the DOE Office of Biological and Environmental Research at PNNL; CNM at ANL, supported by DOE contract DE-AC02-06CH11357; NERSC, supported by DOE contract DE-AC02-05CH11231; and UW-Madison Center for High Throughput Computing (CHTC), supported by UW-Madison the Advanced Computing Initiative, the Wisconsin Alumni Research Foundation the Wisconsin Institutes for Discovery, and the National Science Foundation and is an active member of the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy's Office of Science. A portion of this research was completed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. Z.D.H. gratefully acknowledges support from the National Science Foundation Graduate Research Fellowship under Grant DGE-1650044 and the Georgia Tech-ORNL Fellowship.
| Funders | Funder number |
|---|---|
| Advanced Computing Initiative | |
| Center for Nanophase Materials Sciences | |
| DOE Office of Biological and Environmental Research | |
| DOE Office of Science | |
| Department of Energy-Basic Energy Sciences | |
| Division of Chemical Sciences | DE-FG02-05ER15731 |
| Georgia Tech-ORNL | |
| Oak Ridge National Laboratory | |
| UW-Madison | |
| UW-Madison the Advanced Computing Initiative | |
| Wisconsin Institutes for Discovery | |
| National Science Foundation | |
| U.S. Department of Energy | DE-AC02-05CH11231, DE-AC02- 06CH11357 |
| Wisconsin Alumni Research Foundation | |
| Office of Science | DGE-1650044 |
| Biological and Environmental Research | |
| Georgia Institute of Technology | |
| College of Engineering, University of Wisconsin-Madison | |
| Pacific Northwest National Laboratory |
Keywords
- density functional theory
- facet-dependent catalysis
- fcc structure
- nanocages
- ruthenium