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Insights into the Structural Dynamics of Pt/CeO2 Single-Site Catalysts during CO Oxidation

التفاصيل البيبلوغرافية
العنوان: Insights into the Structural Dynamics of Pt/CeO2 Single-Site Catalysts during CO Oxidation
المؤلفون: Paolo Dolcet, Florian Maurer, Maria Casapu, Jan-Dierk Grunwaldt
المصدر: Catalysts, Vol 11, Iss 5, p 617 (2021)
بيانات النشر: MDPI AG, 2021.
سنة النشر: 2021
المجموعة: LCC:Chemical technology
LCC:Chemistry
مصطلحات موضوعية: Pt single sites, operando, CO oxidation, X-ray absorption spectroscopy, MCR-ALS, Chemical technology, TP1-1185, Chemistry, QD1-999
الوصف: Despite their high atomic dispersion, single site catalysts with Pt supported on CeO2 were found to have a low activity during oxidation reactions. In this study, we report the behavior of Pt/CeO2 single site catalyst under more complex gas mixtures, including CO, C3H6 and CO/C3H6 oxidation in the absence or presence of water. Our systematic operando high-energy resolution-fluorescence-detected X-ray absorption near-edge structure (HERFD-XANES) spectroscopic study combined with multivariate curve resolution with alternating least squares (MCR-ALS) analysis identified five distinct states in the Pt single site structure during CO oxidation light-off. After desorption of oxygen and autoreduction of Pt4+ to Pt2+ due to the increase of temperature, CO adsorbs and reduces Pt2+ to Ptδ+ and assists its migration with final formation of PtxΔ+ clusters. The derived structure–activity relationships indicate that partial reduction of Pt single sites is not sufficient to initiate the conversion of CO. The reaction proceeds only after the regrouping of several noble metal atoms in small clusters, as these entities are probably able to influence the mobility of the oxygen at the interface with ceria.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 2073-4344
54651824
Relation: https://www.mdpi.com/2073-4344/11/5/617; https://doaj.org/toc/2073-4344
DOI: 10.3390/catal11050617
URL الوصول: https://doaj.org/article/36ecd54651824817812fb77dc46ec120
رقم الأكسشن: edsdoj.36ecd54651824817812fb77dc46ec120
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:20734344
54651824
DOI:10.3390/catal11050617