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2024 (English)In: ACS Catalysis, E-ISSN 2155-5435, Vol. 14, no 5, p. 3191-3197Article in journal (Refereed) Published
Abstract [en]
We provide experimental evidence that is inconsistent with often proposed Langmuir−Hinshelwood (LH) mechanistic hypotheses for water-promoted CO oxidation over Au–Fe2O3. Passing CO and H2O, but no O2, over Au-γ-Fe2O3 at 25 °C, we observe significant CO2 production, inconsistent with LH mechanistic hypotheses. Experiments with H218O further show that previous LH mechanistic proposals cannot account for water-promoted CO oxidation over Au-γ-Fe2O3. Guided by density functional theory, we instead postulate a water-promoted Mars–van Krevelen (w-MvK) reaction. Our proposed w-MvK mechanism is consistent both with observed CO2 production in the absence of O2 and with CO oxidation in the presence of H218O and 16O2. In contrast, for Au-TiO2, our data is consistent with previous LH mechanistic hypotheses.
Keywords
CO oxidation, Mars−van Krevelen, Langmuir−Hinshelwood, mechanism, Au Fe2O3, TiO2
National Category
Physical Chemistry Inorganic Chemistry
Identifiers
urn:nbn:se:su:diva-227301 (URN)10.1021/acscatal.3c05978 (DOI)001166445100001 ()38449533 (PubMedID)2-s2.0-85185599124 (Scopus ID)
2024-03-192024-03-192024-07-04Bibliographically approved