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

Journal Article · Thu Jan 01 00:00:00 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 Lab. (ORNL), Oak Ridge, TN (United States). High Temperature Materials Lab. (HTML)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 982389
• Journal Information: Science, Vol. 325, Issue 5948; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

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