fulltext.study @t Gmail

The role of exposed silver in CO oxidation over MgO(0 0 1)/Ag(0 0 1) thin films

Paper ID Volume ID Publish Year Pages File Format Full-Text
54553 47014 2015 8 PDF Available
Title
The role of exposed silver in CO oxidation over MgO(0 0 1)/Ag(0 0 1) thin films
Abstract

•The catalytic activity of ultrathin and thick MgO(0 0 1)/Ag(0 0 1) thin films has been examined.•Ultrathin MgO(0 0 1)/Ag(0 0 1) films are more reactive than thick films, but less reactive than Ag(0 0 1).•Ag remains exposed on the surface for MgO film thicknesses of at least 10 monolayers.•Ultrathin films are highly reactive and susceptible to surface poisoning by carbonate formation.

The reactivity of MgO(0 0 1) films deposited on Ag(0 0 1) and Mo(0 0 1) in CO oxidation as a function of oxide film thickness was investigated experimentally at ambient pressure reaction conditions. MgO films grown on Mo(0 0 1) were found to be inactive in CO oxidation, whereas activity enhancement with decreasing oxide film thickness was observed for MgO(0 0 1)/Ag(0 0 1). In situ infrared and post-reaction X-ray photoemission data showed that ultra-thin MgO films interact much more strongly with the reactants and residual water than bulk-like MgO. Poisoning of the MgO surfaces by the resultant accumulation of carbonate and hydroxyl species is suggested to inhibit the reactivity in CO oxidation. Detailed investigations of the surface structure of MgO(0 0 1)/Ag(0 0 1) films indicate that silver ad-islands on Ag(0 0 1), which are formed during MgO growth, are responsible for the enhancement of CO oxidation activity over ultrathin MgO(0 0 1)/Ag(0 0 1) films.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (143 K)Download as PowerPoint slide

Keywords
Ultrathin films; Oxide surfaces; Reactivity; CO oxidation; Charge transfer
First Page Preview
The role of exposed silver in CO oxidation over MgO(0 0 1)/Ag(0 0 1) thin films
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 Today - Volume 240, Part B, 1 February 2015, Pages 206–213
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