Synthesis of Pt鈥揚d Core鈥揝hell Nanostructures by Atomic Layer Deposition: Application in Propane Oxidative Dehydrogenation to Propylene

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• 作者：Yu Lei ; Bin Liu ; Junling Lu ; Rodrigo J. Lobo-Lapidus ; Tianpin Wu ; Hao Feng ; Xiaoxing Xia ; Anil U. Mane ; Joseph A. Libera ; Jeffrey P. Greeley ; Jeffrey T. Miller ; Jeffrey W. Elam
• 刊名：Chemistry of Materials
• 出版年：2012
• 出版时间：September 25, 2012
• 年：2012
• 卷：24
• 期：18
• 页码：3525-3533
• 全文大小：429K
• 年卷期：v.24,no.18(September 25, 2012)
• ISSN：1520-5002

文摘

Atomic layer deposition (ALD) was employed to synthesize supported Pt鈥揚d bimetallic particles in the 1 to 2 nm range. The metal loading and composition of the supported Pt鈥揚d nanoparticles were controlled by varying the deposition temperature and by applying ALD metal oxide coatings to modify the support surface chemistry. High-resolution scanning transmission electron microscopy images showed monodispersed Pt鈥揚d nanoparticles on ALD Al₂O₃- and TiO₂-modified SiO₂ gel. X-ray absorption spectroscopy revealed that the bimetallic nanoparticles have a stable Pt-core, Pd-shell nanostructure. Density functional theory calculations revealed that the most stable surface configuration for the Pt鈥揚d alloys in an H₂ environment has a Pt-core, Pd-shell nanostructure. In comparison to their monometallic counterparts, the small Pt鈥揚d bimetallic core鈥搒hell nanoparticles exhibited higher activity in propane oxidative dehydrogenation as compared to their physical mixture.

Keywords:

atomic layer deposition; platinum; palladium; bimetallic nanoparticles; catalyst