Structure Sensitivity of Alkynol Hydrogenation on Shape- and Size-Controlled Palladium Nanocrystals: Which Sites Are Most Active and Selective?

Détails

Ressource 1Télécharger: Crespo-JACS-2011-AAM.pdf (4536.73 [Ko])
Etat: Serval
Version: Author's accepted manuscript
Document(s) secondaire(s)
Télécharger: ja204557m_si_001.pdf (913.06 [Ko])
Etat: Serval
Version: Supplementary document
ID Serval
serval:BIB_46E8480BF2C4
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Structure Sensitivity of Alkynol Hydrogenation on Shape- and Size-Controlled Palladium Nanocrystals: Which Sites Are Most Active and Selective?
Périodique
Journal of the American Chemical Society
Auteur(s)
Crespo-Quesada Micaela, Yarulin Artur, Jin Mingshang, Xia Younan, Kiwi-Minsker Lioubov
ISSN
0002-7863
1520-5126
ISSN-L
0002-7863
Statut éditorial
Publié
Date de publication
17/08/2011
Peer-reviewed
Oui
Volume
133
Numéro
32
Pages
12787-12794
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
Publication Status: ppublish
Résumé
The activity and selectivity of structure-sensitive reactions are strongly correlated with the shape and size of the nanocrystals present in a catalyst. This correlation can be exploited for rational catalyst design, especially if each type of surface atom displays a different behavior, to attain the highest activity and selectivity. In this work, uniform Pd nanocrystals with cubic (in two different sizes), octahedral, and cuboctahedral shapes were synthesized through a solution-phase method with poly(vinyl pyrrolidone) (PVP) serving as a stabilizer and then tested in the hydrogenation of 2-methyl-3-butyn-2-ol (MBY). The observed activity and selectivity suggested that two types of active sites were involved in the catalysis--those on the planes and at edges--which differ in their coordination numbers. Specifically, semihydrogenation of MBY to 2-methyl-3-buten-2-ol (MBE) occurred preferentially at the plane sites regardless of their crystallographic orientation, Pd(111) and/or Pd(100), whereas overhydrogenation occurred mainly at the edge sites. The experimental data can be fit with a kinetic modeling based on a two-site Langmuir-Hinshelwood mechanism. By considering surface statistics for nanocrystals with different shapes and sizes, the optimal catalyst in terms of productivity of the target product MBE was predicted to be cubes of roughly 3-5 nm in edge length. This study is an attempt to close the material and pressure gaps between model single-crystal surfaces tested under ultra-high-vacuum conditions and real catalytic systems, providing a powerful tool for rational catalyst design.

Mots-clé
Alkynes/chemistry, Catalysis, Hydrogenation, Nanoparticles/chemistry, Nanoparticles/ultrastructure, Nanotechnology/methods, Palladium/chemistry, Particle Size, Pentanols/chemistry, Colloid and Surface Chemistry, Biochemistry, General Chemistry, Catalysis
Pubmed
Web of science
Création de la notice
10/11/2017 11:04
Dernière modification de la notice
29/03/2018 9:06
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