The critical role of water at the gold-titania interface in catalytic CO oxidation

Johnny Saavedra, Hien A. Doan, Christopher J. Pursell, Lars C. Grabow, Bert D. Chandler

Research output: Contribution to journalReview articlepeer-review

Abstract

We provide direct evidence of a water-mediated reaction mechanism for room-temperature CO oxidation over Au/TiO2catalysts. A hydrogen/deuterium kinetic isotope effect of nearly 2 implicates O-H(D) bond breaking in the rate-determining step. Kinetics and in situ infrared spectroscopy experiments showed that the coverage of weakly adsorbed water on TiO2largely determines catalyst activity by changing the number of active sites. Density functional theory calculations indicated that proton transfer at the metal-support interface facilitates O2binding and activation; the resulting Au-OOH species readily reacts with adsorbed Au-CO, yielding Au-COOH. Au-COOH decomposition involves proton transfer to water and was suggested to be rate determining. These results provide a unified explanation to disparate literature results, clearly defining the mechanistic roles of water, support OH groups, and the metal-support interface.

Original languageEnglish (US)
Pages (from-to)1599-1602
Number of pages4
JournalScience
Volume345
Issue number6204
DOIs
StatePublished - Sep 26 2014

All Science Journal Classification (ASJC) codes

  • General

Fingerprint Dive into the research topics of 'The critical role of water at the gold-titania interface in catalytic CO oxidation'. Together they form a unique fingerprint.

Cite this