Oxidation of Small Supported Platinum-based Nanoparticles Under Near-Ambient Pressure Exposure to Oxygen

Autor: Fabrice Bournel, Rabah Benbalagh, Heloise Tissot, Mathieu G. Silly, Yawei Xu, Jean-Jacques Gallet, Giorgia Olivieri, François Rochet, Fausto Sirotti, Robert Fagiewicz, Ahmed Naitabdi, Anthony Boucly
Přispěvatelé: Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Ile-de-France Region (Photoemission Environnementale en Ile-de-France, SESAME) [090003524], Agence Nationale de la Recherche (Surfaces underă Ambient Pressure with Electron Spectroscopies) [ANR- 08-BLAN-0096], Université Pierre et Marie Curie, LABEX MiChem (UPMC)
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Topics in Catalysis
Topics in Catalysis, Springer Verlag, 2016, 59 (5-7), pp.550-563. ⟨10.1007/s11244-015-0529-z⟩
Topics in Catalysis, 2016, 59 (5-7), pp.550-563. ⟨10.1007/s11244-015-0529-z⟩
ISSN: 1022-5528
1572-9028
Popis: International audience; The investigation of nanocatalysts under their working conditions of pressures and temperatures represents a real strategy toward a realistic understanding of their chemical reactivity and related issues. Additionally, the reduction of Pt load in the catalysts while maintaining their optimum performances is essential to large scale practical applications. Here, we show that small PtZn bimetallic nanoparticles (NPs) supported on the rutile and reduced TiO2(110)-(1 × 1) surface can be prepared by a two step consecutive deposition process where Pt was deposited first and followed by Zn. In situ synchrotron-based near ambient pressure photoemission spectroscopy experiments are used to monitor the evolution of the oxidation states and surface elemental composition of pure Pt and PtZn NPs under high exposure to O2 pressure. The formation of stable Pt surface oxide was evidenced for both pure and PtZn NPs. While a sizeable encapsulation of pure Pt NPs by TiOx was seen after annealing at 440 K under 1 mbar of O2, no such effect was noticed for PtZn NPs. The formation of a zinc oxide layer on PtZn NPs enhances the stability of the NPs and induces a partial reduction of the TiO2(110) surface. Spontaneous formation of a Pt–Zn alloy phase at room temperature was seen in PtZn NPs.
Databáze: OpenAIRE
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