1. Structure Sensitivity of Acrolein Hydrogenation by Platinum Nanoparticles on Ba x Sr 1โ x TiO 3 Nanocuboids
- Author
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Christopher L. Marshall, Christopher M. Engelhardt, Peter C. Stair, James A. Enterkin, Donald E Ellis, Kenneth R. Poeppelmeier, and Robert M. Kennedy
- Subjects
Valence (chemistry) ,Chemistry ,Organic Chemistry ,Inorganic chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Platinum nanoparticles ,01 natural sciences ,Catalysis ,Surface energy ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Adsorption ,Density of states ,Physical chemistry ,Density functional theory ,Physical and Theoretical Chemistry ,Allyl alcohol ,0210 nano-technology - Abstract
The structure sensitivity of Pt nanoparticles (PtN) for gas-phase acrolein (AC) hydrogenation was probed for PtN on BaxSr1-xTiO3 nanocuboid supports with (001) facets in a combined theoretical and experimental study. In situ selectivity for allyl alcohol increased with Sr concentration in the support, corresponding 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 Pt surface, edge, and corner morphologies were developed as compact representations of adsorption and reaction sites. Density functional theory (DFT) was used as the primary modeling tool of 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 due to its interaction with the substrate. Bader topological atom, spherical volume averaging charge, and modified bond valence sum (BVS) analyses were used to understand bonding structure. Density of states analysis was performed for 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.
- Published
- 2018
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