Abstract
The structure sensitivity of Pt nanoparticles (PtN) for gas-phase acrolein (AC) hydrogenation was probed for PtN on BaxSr1−xTiO3 nanocuboid supports with (0 0 1) facets in a combined theoretical and experimental study. The in situ selectivity for allyl alcohol increased with the increase of the Sr concentration in the support, which corresponds to modifications in the stable Winterbottom shape and lattice strain of the Pt nanoparticles as a result of the interfacial energy between Pt and the BaxSr1−xTiO3 supports. “Local model” nanofacets of the Pt surface, edge, and corner morphologies were developed as compact representations of adsorption and reaction sites. DFT was used as the primary modeling tool for the equilibrium adsorption states. We argue that adsorption on edge sites is critically important for the overall allyl alcohol selectivity of PtN catalysts. A simple model was developed to represent PtN strain effects caused by its interaction with the substrate. Bader topological atom, spherical volume averaging charge, and modified bond valence sum analyses were used to understand the bonding structure. Density of states analysis was performed for the structures of PtN, adsorbed AC, and intermediate products to examine adsorbate–particle interactions. The simulated hydrogenation of AC on PtN nanofacets was compared to the in situ hydrogenation of AC by PtN on BaxSr1−xTiO3 to examine the effects of facet, edge, and corner sites on the overall selectivity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 632-641 |
| Number of pages | 10 |
| Journal | ChemCatChem |
| Volume | 10 |
| Issue number | 3 |
| DOIs | |
| State | Published - Feb 7 2018 |
Funding
This work was funded in part by the Institute for Atom-efficient Chemical Transformations (IACT), an Energy Frontier Research Center, funded through the U.S. Department of Energy, Office of Basic Energy Sciences, and in part by the Northwestern University Institute for Catalysis in Energy Processes (ICEP), funded through the US Department of Energy, Office of Basic Energy Science (award number DE-FG02-03-ER15457). This work made use of the EPIC facility (NUANCE Center North-western University), which has received support from the MRSEC program (NSF DMR1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); and the State of Illinois, through the IIN. Additional electron microscopy was accomplished at the Electron Microscopy Center for Materials Research at Argonne National Laboratory, a U.S. Department of Energy Office of Science Laboratory operated under Contract No. DE-AC02-06CH11357 by U. Chicago Argonne, LLC. The authors would like to thank Junling Lu and Jeff Elam for the Pt ALD on our samples. This work was supported in part through the computational resources and staff contributions provided for the Quest high-performance computing facility at Northwestern University which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology. Molecular images were generated using the VESTA software.[87]
Keywords
- density functional calculations
- gas-phase reactions
- hydrogenation
- nanoparticles
- platinum
ASJC Scopus subject areas
- Catalysis
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry