Size effect in the oxidation of platinum nanoparticles on graphite with nitrogen dioxide: An XPS and STM study

Kalinkin, A. V.; Sorokin, A. A.; Smirnov, M. Yu.; Bukhtiyarov, Valerii I.

doi:10.1134/s0023158414030045

Cited by 42 publications

(21 citation statements)

References 25 publications

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“…The combination of these methods provided the most complete information regarding the composition, state and structure of the surface of the NPs and could facilitate the understanding of the origin of the size effect. 80 In fact, only Pt NPs with a size smaller than 2.5 nm were found to oxidize to a mixture of PtO and PtO 2 under the experimental conditions of that study. Chakroune et al studied acetate-and thiol-coated Ru NPs with XPS, XAS and HRTEM.…”

Section: X-ray-based Techniquesmentioning

confidence: 66%

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

2018

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Nanostructures have attracted huge interest as a rapidly growing class of materials for many applications. Several techniques have been used to characterize the size, crystal structure, elemental composition and a variety of other physical properties of nanoparticles. In several cases, there are physical properties that can be evaluated by more than one technique. Different strengths and limitations of each technique complicate the choice of the most suitable method, while often a combinatorial characterization approach is needed. In addition, given that the significance of nanoparticles in basic research and applications is constantly increasing, it is necessary that researchers from separate fields overcome the challenges in the reproducible and reliable characterization of nanomaterials, after their synthesis and further process (e.g. annealing) stages. The principal objective of this review is to summarize the present knowledge on the use, advances, advantages and weaknesses of a large number of experimental techniques that are available for the characterization of nanoparticles. Different characterization techniques are classified according to the concept/group of the technique used, the information they can provide, or the materials that they are destined for. We describe the main characteristics of the techniques and their operation principles and we give various examples of their use, presenting them in a comparative mode, when possible, in relation to the property studied in each case.

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Section: X-ray-based Techniquesmentioning

confidence: 66%

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

2018

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“…Kalinkin et al [6] used XPS and scanning tunnel microscopy (STM) for studying the interaction of NO 2 with the particles of platinum evaporeted onto the sur face of highly oriented pyrolytic graphite at room tem perature and a pressure of 3 × 10 -6 mbar. It was found that, under these conditions, only small platinum par ticles of size ~2.5 nm underwent oxidation with the formation of PtO and PtO 2 particles, whereas larger particles (~5.5 nm) remained in a metallic state.…”

Section: Introductionmentioning

confidence: 99%

Size effect in the oxidation–reduction processes of platinum particles supported onto silicon dioxide

et al. 2015

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Abstract-The interaction of the Pt/SiO 2 model catalysts as thin films on the surface of tantalum supports with a mixture of NO + O 2 (1 : 1) was studied by X ray photoelectron spectroscopy. The pressure of the reac tion mixture was varied from 6 to 64 mbar, and the temperature was varied from room temperature to 500°C. Two types of the catalysts, in which the Pt/Si atomic ratios were ~0.1 and ~0.3 (0.1 Pt/SiO 2 and 0.3 Pt/SiO 2 , respectively) according to the XPS data, were studied. In 0.1 Pt/SiO 2 , the particles of platinum predomi nantly had a size from 1 to 2.5 nm; a wide Pt particle size distribution in a range from 1 to 15 nm with a max imum at ~4 nm was characteristic of 0.3 Pt/SiO 2 . The interaction of all of the samples with NO + O 2 at room temperature led to the dissolution of oxygen atoms in the bulk of platinum metal particles. As the reaction temperature was increased, PtO x platinum oxide particles were formed: from small Pt particles in 0.1 Pt/SiO 2 at 300°C and from larger particles in 0.3 Pt/SiO 2 at 400-500°C. It was established that the reactivity of plat inum oxide particles toward hydrogen also depended on the particle size. The small particles of platinum oxide were converted into platinum metal under the action of hydrogen (16 mbar) at 300°C. The coarse par ticles of PtO x in the samples of 0.3 Pt/SiO 2 were reduced much more easily starting with room temperature.

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“…7b, Table 2): the percentage of PtO 2 is lower, and the greater part of the platinum remains in the form of metal particles containing dissolved oxygen atoms. This finding is not surprising, because it is well known that larger plati num particles turn less readily into oxides [13,30], but, apparently, they dissolve oxygen rather readily [30].…”

Section: Interaction Between No 2 and Pt-bao/tio 2 -Zromentioning

confidence: 77%

“…The model catalyst-NO 2 interaction procedure is detailed in an earlier work [13]. NO 2 was produced directly in the vacuum chamber via lead nitrate decomposition:…”

Section: Synthesis Of Model Catalystsmentioning

confidence: 99%

Model sulfur-resistant NSR catalysts: An XPS study of the interaction of BaO/TiO2-ZrO2 and Pt-BaO/TiO2-ZrO2 with NO2

et al. 2015

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The interaction of NO 2 with BaO/TiO 2 -ZrO 2 and Pt-BaO/TiO 2 -ZrO 2 model NO x storagereduction (NSR) catalysts prepared on the surface of FeCrAl alloy substrates has been investigated by X ray photoelectron spectroscopy. The action of nitrogen dioxide on these catalysts at room temperature causes the consecutive formation of surface barium nitrite and nitrate. Supposedly, NO 2 reduction yielding barium nitrite at the early stages of the interaction is due to the oxidation of amorphous carbon impurities. The intro duction of platinum into the catalyst accelerates nitrogen dioxide sorption. On being exposed to NO 2 for a long time, platinum oxidizes to PtO 2 . This process is more pronounced in the sample containing freshly deposited platinum. Heat treatment of this sample in a vacuum, which coarsens the platinum particles, makes them more resistant to oxidation.

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Size effect in the oxidation of platinum nanoparticles on graphite with nitrogen dioxide: An XPS and STM study

Cited by 42 publications

References 25 publications

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

Size effect in the oxidation–reduction processes of platinum particles supported onto silicon dioxide

Model sulfur-resistant NSR catalysts: An XPS study of the interaction of BaO/TiO2-ZrO2 and Pt-BaO/TiO2-ZrO2 with NO2

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