fulltext.study @t Gmail

Theoretical study of CO adsorption on Au catalysts under environmental catalytic conditions

Paper ID Volume ID Publish Year Pages File Format Full-Text
49661 46759 2014 6 PDF Available
Title
Theoretical study of CO adsorption on Au catalysts under environmental catalytic conditions
Abstract

•Hybrid HSE06 functional predicts CO top site adsorption on Au surfaces and adatoms.•HSE06 and standard GGA functionals may bound the true CO–Au interaction strength.•7-coordinated Au atoms dominate CO adsorption features at low temperatures.•6-coordinated Au atoms dominate CO adsorption in environmental catalytic conditions.•The shape of a Au nanoparticle may strongly influence its activity for CO oxidation.

Density Functional Theory calculations with both standard GGA and hybrid functionals are performed on Au adatoms, steps, and low index surfaces with coordination numbers (CNs) varying from 3 to 9. The results are used to study adsorption thermodynamics and reactivity of CO on Au nanoparticles. We find that the hybrid functional improves calculated site preferences and predicts CO top site adsorption, regardless of the Au CN, in good agreement with experiments. The calculated adsorption energies vary monotonically with respect to Au CNs, and the results from the hybrid functional are around 20% smaller than the corresponding values from the GGA–PBE functional. A comparison with experimental adsorption energies suggests that these functionals may bound the true CO–Au interaction strength, and seven-coordinated Au atoms may be the active low-coordinated sites on many Au single crystal surfaces. However, thermodynamic analysis on Wulff-like Au particles at ambient temperatures shows that, even though the number of 6-coordinated corner Au atoms is much less than the number of 7-coordinated edge Au atoms and of higher-coordinated Au atoms, they are the dominant sites for CO adsorption on Au nanoparticles with sizes up to 10 nm. In addition, we find that CO adsorption is not influenced by the shape of Au nanoparticles, but the CO oxidation reaction may be.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
CO adsorption; Au catalyst; DFT; Wulff construction; Environmental catalysis
First Page Preview
Theoretical study of CO adsorption on Au catalysts under environmental catalytic conditions
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
Publisher
Database: Elsevier - ScienceDirect
Journal: Catalysis Communications - Volume 52, 5 July 2014, Pages 78–83
Authors
, ,
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