Role of small Pd ensembles in boosting CO oxidation in AuPd alloys

Hyung Chul Ham, J. Adam Stephens, Gyeong S. Hwang, Jonghee Han, SukWoo Nam, Tae Hoon Lim

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

We present a theoretical explanation on how PdAu alloy catalysts can enhance the oxidation of CO molecules based on density functional theory calculations of CO adsorption and oxidation on AuPd/Pd(111) surfaces. Our study suggests that the enhanced activity is largely attributed to the possible existence of "partially-poisoned" Pd ensembles that accommodate fewer CO molecules than Pd atoms. Whereas the oxidation of preadsorbed CO is likely governed by O 2 trapping, our study shows that small Pd ensembles such as dimers and compact trimers tend to provide more active sites than larger ensembles; CO adsorbed on a Pd monomer is found to react hardly with O 2 to form CO 2. In addition, we find the tendency of CO-induced Pd agglomeration, which may in turn facilitate CO oxidation by creating more dimers and compact trimers as compared with the adsorbate-free surface where monomers are likely prevailing.

Original languageEnglish
Pages (from-to)566-570
Number of pages5
JournalJournal of Physical Chemistry Letters
Volume3
Issue number5
DOIs
Publication statusPublished - 2012 Mar 1
Externally publishedYes

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Carbon Monoxide
Oxidation
Dimers
Monomers
Molecules
Adsorbates
Density functional theory
Agglomeration
Adsorption
Atoms
Catalysts
Catalytic Domain

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Role of small Pd ensembles in boosting CO oxidation in AuPd alloys. / Ham, Hyung Chul; Stephens, J. Adam; Hwang, Gyeong S.; Han, Jonghee; Nam, SukWoo; Lim, Tae Hoon.

In: Journal of Physical Chemistry Letters, Vol. 3, No. 5, 01.03.2012, p. 566-570.

Research output: Contribution to journalArticle

Ham, Hyung Chul ; Stephens, J. Adam ; Hwang, Gyeong S. ; Han, Jonghee ; Nam, SukWoo ; Lim, Tae Hoon. / Role of small Pd ensembles in boosting CO oxidation in AuPd alloys. In: Journal of Physical Chemistry Letters. 2012 ; Vol. 3, No. 5. pp. 566-570.
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