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Synthesis of hydrotalcite-supported shape-controlled Pd nanoparticles by a precipitation–reduction method

Paper ID Volume ID Publish Year Pages File Format Full-Text
41088 45877 2012 11 PDF Available
Title
Synthesis of hydrotalcite-supported shape-controlled Pd nanoparticles by a precipitation–reduction method
Abstract

A Pd catalyst supported on a layered double hydroxide (LDH or hydrotalcite-like material) has been synthesized in a one step reaction using a precipitation–reduction method in which hydrolysis of hexamethylenetetramine was used to both precipitate the LDH by virtue of the resulting increase in pH and provide formaldehyde which reduces the Pd2+ precursor to Pd0. The resulting Pd nanoparticles were mostly tetrahedral in shape, and were highly dispersed on the surface of the LDH. After introducing a capping agent during the synthesis, the morphology of the Pd particles changed to truncated octahedral, although a similar high degree of dispersion was obtained. Compared with a conventional impregnated catalyst composed of pseudo-spherical Pd particles, catalysts prepared by the new method showed both higher activity and selectivity in the hydrogenation of acetylene. The enhanced activity is due to the specific morphology of the Pd particles, which results in their higher dispersion, while the higher selectivity is attributed to the Pd–C phase formed in the catalyst during the reaction. Furthermore, compared with the truncated octahedral Pd particles enclosed by (1 1 1) and (1 0 0) facets, the tetrahedral particles with only (1 1 1) facets exposed showed higher ethylene selectivity, suggesting that the Pd (1 1 1) facet is the preferred facet in the selective hydrogenation of acetylene to ethylene.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (179 K)Download as PowerPoint slideHighlights► LDHs supported Pd catalysts were prepared by a precipitation–reduction method. ► Tetrahedral Pd nanoparticles were highly dispersed on the surface of LDHs. ► By adding CTAB as a capping agent, truncated octahedral particles were obtained. ► Specific Pd shapes lead to higher surface-to-volume ratio and catalytic activity. ► Pd (1 1 1) is regarded as the preferred facet in selective acetylene hydrogenation.

Keywords
Supported metal catalyst; Pd morphology; Layered double hydroxide; Selective acetylene hydrogenation
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Synthesis of hydrotalcite-supported shape-controlled Pd nanoparticles by a precipitation–reduction method
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volumes 413–414, 31 January 2012, Pages 10–20
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us