Co-ordinatively Unsaturated Al3+ Centers as Binding Sites for Active Catalyst Phases of Platinum on -Al2O3

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Science

DOI:https://doi.org/10.1126/science.1176745· OSTI ID:982389

Kwak, Ja Hun ^[1]; Hu, Jiangzhi ^[1]; Mei, Donghei ^[1]; Yi, Cheol-Woo ^[1]; Kim, Do Heui ^[1]; Peden, Charles ^[1]; Allard, Jr, Lawrence Frederick ^[2]; Szanyi, Janos ^[1]

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1. Pacific Northwest National Laboratory (PNNL)
2. ORNL

In many heterogeneous catalysts, the interaction of metal particles with their oxide support can alter the electronic properties of the metal and can play a critical role in determining particle morphology and maintaining dispersion. We used a combination of ultrahigh magnetic field, solid-state magic-angle spinning nuclear magnetic resonance spectroscopy, and high-angle annular dark-field scanning transmission electron microscopy coupled with density functional theory calculations to reveal the nature of anchoring sites of a catalytically active phase of platinum on the surface of a {gamma}-Al{sub 2}O{sub 3} catalyst support material. The results obtained show that coordinatively unsaturated pentacoordinate Al{sup 3+} (Al{sub penta}{sup 3+}) centers present on the (100) facets of the {gamma}-Al{sub 2}O{sub 3} surface are anchoring Pt. At low loadings, the active catalytic phase is atomically dispersed on the support surface (Pt/Al{sub penta}{sup 3+} = 1), whereas two-dimensional Pt rafts form at higher coverages.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Temperature Materials Laboratory
• Sponsoring Organization: EE USDOE - Office of Energy Efficiency and Renewable Energy (EE)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 982389
• Journal Information: Science, Journal Name: Science Journal Issue: 5948 Vol. 325; ISSN 1095-9203; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALUMINIUM OXIDES
Al3+ binding sites
CATALYST SUPPORTS
CATALYSTS
DENSITY FUNCTIONAL METHOD
NMR
NUCLEAR MAGNETIC RESONANCE
PLATINUM
SCANNING ELECTRON MICROSCOPY
STEM
SURFACE PROPERTIES
TRANSMISSION ELECTRON MICROSCOPY
alumina
barium oxide
catalyst
pentacoordinate