Study of active surface centers of Pt/CeO2 catalysts prepared using radio-frequency plasma sputtering technique

Stadnichenko, A. I.; Muravev, Valery; Koscheev, S.V.; Зайковский, В. И.; Aleksandrov, Hristiyan A.; Neyman, Konstantin M.; Boronin, Andrei I.

doi:10.1016/j.susc.2018.10.002

Cited by 36 publications

(27 citation statements)

References 79 publications

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“…On the other hand, the barrier is significantly higher for Pt at 1.14 eV. This can well explain the experimentally observed preference for Pt 4+ substitutions in Pt-ceria solid solutions [44][45][46]. The Pt oxidation states in Pt-dop-I and Pt-dop-II are 4+ and 2+, respectively.…”

Section: Stability Tm-doped Ceo2supporting

confidence: 75%

Lattice oxygen activation in transition metal doped ceria

Zhang

Muravev

et al. 2020

Chinese Journal of Catalysis

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Section: Stability Tm-doped Ceo2supporting

confidence: 75%

Lattice oxygen activation in transition metal doped ceria

Zhang

Muravev

et al. 2020

Chinese Journal of Catalysis

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“…A pass energy of 40 eV with a step size of 0.1 eV and a dwell time of 0.5 s were typically used for acquiring the core-line spectra. Pt 4f and Ce 3d regions were energy-corrected according to the U”’ component of the Ce 3d core line with a characteristic binding energy of 916.7 eV 54 , 61 , 62 . The peak position of this component is independent of the Ce to Ce ratio (as long as Ce is present), which makes it possible to calibrate the spectra throughout the experiment.…”

Section: Methodsmentioning

confidence: 99%

Tuning Pt-CeO2 interactions by high-temperature vapor-phase synthesis for improved reducibility of lattice oxygen

DeLaRiva²,

et al. 2019

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In this work, we compare the CO oxidation performance of Pt single atom catalysts (SACs) prepared via two methods: (1) conventional wet chemical synthesis (strong electrostatic adsorption–SEA) with calcination at 350 °C in air; and (2) high temperature vapor phase synthesis (atom trapping–AT) with calcination in air at 800 °C leading to ionic Pt being trapped on the CeO2 in a thermally stable form. As-synthesized, both SACs are inactive for low temperature (<150 °C) CO oxidation. After treatment in CO at 275 °C, both catalysts show enhanced reactivity. Despite similar Pt metal particle size, the AT catalyst is significantly more active, with onset of CO oxidation near room temperature. A combination of near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and CO temperature-programmed reduction (CO-TPR) shows that the high reactivity at low temperatures can be related to the improved reducibility of lattice oxygen on the CeO2 support.

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“…The program of processing spectral data created by us, XPS-Calc, was used for the mathematical treatment of the XPS spectra. This software has previously been applied for different systems, including Pt/CeO 2 and Pt/Al 2 O 3 catalysts (Ivanova et al, 2010; Svintsitskiy et al, 2015; Stadnichenko et al, 2017, 2019). The Shirley model and the Gauss–Lorentz functions were used for background subtraction and curve fitting, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…Different synthetic approaches are used to obtain PGM-CeO 2 catalysts with desired improved characteristics (Boronin et al, 2009; Gulyaev et al, 2012, 2014b; Slavinskaya et al, 2015, 2016, 2018; Vasilchenko et al, 2016; Derevyannikova et al, 2017; Kardash et al, 2017; Kibis et al, 2017). Novel physical preparation methods that utilize the action of thermal and electrical fields, such as laser ablation, magnetron sputtering, “solution-combustion” and plasma methods attracted attention of many research groups (Bera et al, 2003; Baidya et al, 2009; Hegde et al, 2009; Gupta and Hegde, 2010; Hinokuma et al, 2014; Slavinskaya et al, 2016, 2018; Vasilchenko et al, 2016; Stadnichenko et al, 2018, 2019). These methods allow obtaining of highly dispersed PGM forms (ions and clusters) on the surface and inside ceria, which ensures the maximal SMSI effect and appearance of new highly active surface species.…”

Section: Introductionmentioning

confidence: 99%

Pt/CeO2 and Pt/CeSnOx Catalysts for Low-Temperature CO Oxidation Prepared by Plasma-Arc Technique

et al. 2019

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We applied a method of plasma arc synthesis to study effects of modification of the fluorite phase of ceria by tin ions. By sputtering active components (Pt, Ce, Sn) together with carbon from a graphite electrode in a helium ambient we prepared samples of complex highly defective composite PtCeC and PtCeSnC oxide particles stabilized in a matrix of carbon. Subsequent high-temperature annealing of the samples in oxygen removes the carbon matrix and causes the formation of active catalysts Pt/CeOx and Pt/CeSnOx for CO oxidation. In the presence of Sn, X-Ray Diffraction (XRD) and High-Resolution Transmission Electron Microscopy (HRTEM) show formation of a mixed phase CeSnOx and stabilization of more dispersed species with a fluorite-type structure. These factors are essential for the observed high activity and thermic stability of the catalyst modified by Sn. X-Ray Photoelectron Spectroscopy (XPS) reveals the presence of both Pt2+ and Pt4+ ions in the catalyst Pt/CeOx, whereas only the state Pt2+ of platinum could be detected in the Sn-modified catalyst Pt/CeSnOx. Insertion of Sn ions into the Pt/CeOx lattice destabilizes/reduces Pt4+ cations in the Pt/CeSnOx catalyst and induces formation of strikingly high concentration (up to 50% at.) of lattice Ce3+ ions. Our DFT calculations corroborate destabilization of Pt4+ ions by incorporation of cationic Sn in Pt/CeOx. The presented results show that modification of the fluorite lattice of ceria by tin induces substantial amount of mobile reactive oxygen partly due to affecting geometric parameters of ceria by tin ions.

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Study of active surface centers of Pt/CeO2 catalysts prepared using radio-frequency plasma sputtering technique

Cited by 36 publications

References 79 publications

Lattice oxygen activation in transition metal doped ceria

Lattice oxygen activation in transition metal doped ceria

Tuning Pt-CeO2 interactions by high-temperature vapor-phase synthesis for improved reducibility of lattice oxygen

Pt/CeO2 and Pt/CeSnOx Catalysts for Low-Temperature CO Oxidation Prepared by Plasma-Arc Technique

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