Poisoning of the Au/TiO2 active site for CO oxidation by NaBr

Sean M. Oxford, Juan Henao, Jeff H. Yang, Jeffrey T. Miller, Mayfair C. Kung, Harold H. Kung

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Au/TiO2 is a highly active catalyst for CO oxidation when Au is dispersed as nanoparticles. However, its catalytic activity is suppressed by residual halide. Using a combination of in-situ FTIR spectroscopy, X-ray absorption spectroscopy, and microreactor studies, changes occurring at the active site upon addition of NaBr to reduced and unreduced catalyst were monitored. The active site is Au0, therefore the unreduced catalyst is inactive. Binding of bromide to Au3+ in the unreduced catalyst inhibited reduction to Au0, thereby preventing activation of the catalyst. Bromide also bound to Au0 sites on the reduced catalyst, inhibiting CO adsorption and activation, resulting in lost catalytic activity. In addition to binding to the Au particles, the bromide also mobilized them, resulting in significantly accelerated agglomeration.

Original languageEnglish
Title of host publication233rd ACS National Meeting, Abstracts of Scientific Papers
Publication statusPublished - Dec 28 2007
Event233rd ACS National Meeting - Chicago, IL, United States
Duration: Mar 25 2007Mar 29 2007

Publication series

NameACS National Meeting Book of Abstracts
ISSN (Print)0065-7727

Other

Other233rd ACS National Meeting
CountryUnited States
CityChicago, IL
Period3/25/073/29/07

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ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

Cite this

Oxford, S. M., Henao, J., Yang, J. H., Miller, J. T., Kung, M. C., & Kung, H. H. (2007). Poisoning of the Au/TiO2 active site for CO oxidation by NaBr. In 233rd ACS National Meeting, Abstracts of Scientific Papers (ACS National Meeting Book of Abstracts).