In situ X-ray Absorption Spectroscopic Study of Fe@FexOy/Pd and Fe@FexOy/Cu Nanoparticle Catalysts Prepared by Galvanic Exchange Reactions
Date
2015
Authors
Yao, Yali
Patzig, Christian
Hu, Yongfeng
Scott, Robert WJ
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American Chemical Society
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Article
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Abstract
Fe@FexOy core–shell nanoparticles have been previously shown to be a versatile support for catalytic metals such as Pd and Cu. However, the resulting structure, metal speciation, and performance of such catalysts in catalytic reactions are still poorly understood. Herein, we synthesize Fe@FexOy-supported Pd and Cu nanoparticles by controlling the molar ratios of Fe@FexOy nanoparticles to Pd2+ or Cu2+ species. Scanning transmission electron microscopy analyses show that Pd or Cu NPs are deposited on the exterior shell of the Fe@FexOy nanoparticles. In situ X-ray absorption near-edge structure (XANES) spectra were used to follow the formation processes of Fe@FexOy/Pd and Fe@FexOy/Cu nanoparticles and the performance of Fe@FexOy/Pd nanoparticles for Suzuki–Miyaura cross-coupling reactions. The results show that different molar ratios of Fe@FexOy nanoparticles to Pd2+ or Cu2+ lead to different morphologies of the resulting supported-NP structures. In situ XANES results show that Fe@FexOy nanoparticles can effectively fully reduce Pd or Cu salts over the course of ∼20 min to give small Pd or larger Cu nanoparticles on the surface and can also rereduce oxidized Pd in Suzuki–Miyaura cross-coupling reactions.
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Keywords
In situ, X-ray absorption spectroscopy, Galvanic Reaction, Iron, Nanoparticles
Citation
Y. Yao, C. Patzig, Y. Hu, R. W. J. Scott, J. Phys. Chem. C , 2015, 119, 21209–21218.
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DOI
10.1021/acs.jpcc.5b06155