Model approach to evaluate particle size effects in electrocatalysis: preparation and properties of Pt nanoparticles supported on GC and HOPG

Cherstiouk, Olga V.; Simonov, P.A.; Savinova, Elena R.

doi:10.1016/s0013-4686(03)00519-x

Cited by 199 publications

(185 citation statements)

References 33 publications

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“…In contrast, a shift of onset potential toward more positive values with decreasing particle size has been found by others. 34,35 Davies et al, 36 in studies of CO electro-oxidation on Ru-modified Pt͑111͒, observed a single sharp oxidation peak at about 0.8 V for the clean Pt͑111͒ surface and the appearance of another peak at lower potentials for Ru-modified surfaces. For increasing Ru coverage the peak at higher potentials decreased and the onset potential of CO oxidation shifted to lower values.…”

Section: Resultsmentioning

confidence: 99%

Influence of Particle Size on the Properties of Pt–Ru∕C Catalysts Prepared by a Microemulsion Method

Godoi

Perez

Villullas

2007

J. Electrochem. Soc.

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Pt-Ru/C nanocatalysts were prepared by a microemulsion method using different values of water/surfactant molar ratio in order to get different particle sizes. Crystallite sizes and structural properties were determined by X-ray diffraction. Particle size and distribution were characterized by transmission electron microscopy and average composition was determined by energydispersive X-ray analysis. Thermogravimetric analysis was used to estimate the amount of supported metals. Differential scanning calorimetry measurements indicated the presence of hydrous ruthenium oxides in the as-prepared catalysts. Results for the oxidation of adsorbed CO as well as for methanol oxidation revealed significant differences in the behavior of the prepared catalysts. All together, the results demonstrate that the variation of particle size produces changes in other properties of the Pt-Ru/C catalysts and that to establish direct correlations between electrocatalytic activity and particle size is not possible because the effects of the different parameters cannot be separated.

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Section: Resultsmentioning

confidence: 99%

Influence of Particle Size on the Properties of Pt–Ru∕C Catalysts Prepared by a Microemulsion Method

Godoi

Perez

Villullas

2007

J. Electrochem. Soc.

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“…Two possible explanations for the decrease in activity with decreasing particle size were given: (1) on smaller particles, the coverage of OH ads increases, thus blocking more empty sites, resulting in a decrease in the methanol decomposition rate, or (2) smaller particles have fewer preferential adsorption sites for methanol. In addition to these findings, Cherstiouk et al [7] observed lower methanol oxidation rates for Pt particles in the range of 1.5-3 nm compared to polycrystalline Pt, which they ascribed to stronger poisoning of the nanoparticles as compared to polycrystalline surfaces due to slower oxidation of CO.…”

Section: Introductionmentioning

confidence: 86%

“…Therefore, understanding of their electrochemical properties is an important issue in the development of efficient fuel cell catalysts. Especially the electrocatalysis of small organic molecules, such as carbon monoxide (CO), methanol (MeOH), and formic acid (HCOOH), is an interesting field of study, as these reactions play an important role in fuel cell catalysis [1,2] and they display pronounced sizedependent catalytic properties [3][4][5][6][7][8][9]. Due to the fact that platinum is one of the most active dehydrogenation catalysts, Pt nanoparticles are of particular significance.…”

Section: Introductionmentioning

confidence: 99%

The electrooxidation of small organic molecules on platinum nanoparticles supported on gold: influence of platinum deposition procedure

Scheijen

Beltramo

Hoeppener

et al. 2007

J Solid State Electrochem

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The electrocatalytic properties of small platinum nanoparticles were investigated for the oxidation of CO, methanol, and formic acid using voltammetry, chronoamperometry, and surface-enhanced Raman spectroscopy. The particles were generated by galvanostatic deposition of platinum on a polished gold surface from an H 2 PtCl 6 containing electrolyte and ranged between 10 and 20 nm in diameter for low platinum surface concentrations, 10 and 120 nm for medium concentrations, and full Pt monolayers for high concentrations. CO stripping and bulk CO oxidation experiments on the particles up to 120 nm in diameter displayed pronounced structural effects. The CO oxidation current-time transients show a current decay for low platinum coverages and a current maximum for medium and high coverages. These results were also observed in the literature for particles of 2-to 5-nm size and agglomerates of these particles. The similarities between the literature and our results, despite large differences in particle size and morphology, suggest that particle structure and morphology are also very important catalytic parameters. Surface-enhanced Raman spectroscopy data obtained for the oxidation of CO on the Pt-modified Au electrodes corroborate this conclusion. A difference in the ratio between CO adsorbed in linear-and bridge-bonded positions on the Pt nanoparticles of different sizes demonstrates the influence of the surface morphology. The oxidation activity of methanol was found to decrease with the particle size, while the formic acid oxidation rate increases. Again, a structural effect is observed for particles of up to ca. 120 nm in diameter, which is much larger than the particles for which a particle size effect was reported in the literature. The particle shape effect for the methanol oxidation reaction can be explained by a reduction in available "ensemble sites" and a reduction in the mobility of CO formed by decomposition of methanol. As formic acid does not require Pt ensemble sites, decreasing the particle size, and thus, the relative number of defects, increases the reaction rate.

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“…Отличие свойств малых частиц от свойств массивного материала давно известно и широко используется, например, в катализаторах [5,6], присадках к моторным маслам, смазочных материалах [7,8], микроэлектронике [9,10]. Теперь показано, что уменьшение раз-меров кристаллитов в металлах ниже некоторой пороговой величи-ны приводит, как правило, к значительному изменению свойств [11][12][13][14][15][16].…”

Section: Introductionunclassified

Nanoscale States in Metals, Alloys, and Intermetallic Compounds: Methods of Manufacture, Structure, Properties

Shevchenko

Stetsenko

2004

Usp. Fiz. Met.

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Наноструктурные металлические материалы, обладающие уникальны-ми свойствами благодаря характерному структурному размеру, сопос-тавимому с межатомными расстояниями в кристалле, нашли широкое применение и являются основой многих современных технологий. Цель данного обзора -представить общую картину исследований наност-руктурных состояний в компактных металлах, сплавах и интерметал-лидах, охарактеризовать основные методы получения компактных на-ноструктурных материалов, особенности их структуры и свойств. Так же кратко представлены основные модели, объясняющие особенности строения и аномальные свойства металлов и сплавов в нанокристалли-ческом состоянии.Наноструктурні металічні матеріали, що мають унікальні властивості завдяки характерному структурному параметру, співставимому із мі-жатомними відстанями у кристалі, знайшли широке застосування та є основою багатьох сучасних технологій. Мета цього огляду -предста-вити загальну картину досліджень наноструктурних станів у компакт-них металах, сплавах та інтерметалічних сполуках, дати характерис-тику основних методів отримання компактних наноструктурних мате-ріалів, їх властивостей та структурних особливостей. Також стисло представлено основні моделі, що пояснюють особливості будови та ано-мальні властивості металів та сплавів у нанокристалічному стані. Nanocrystalline metallic materials have been recognized as perspective materials for a wide range of modern technologies due to their unique properties, occurring because of their mainly structural parameters, which are comparable with the interatomic distances. This review objective is to characterize the current state of art in investigation of the nanoscale metals, alloys, and intermetallic compounds. Basic methods for preparing compact nanocrystalline materials are discussed. Recent results Успехи физ. мет. / Usp. Fiz. Met. 2004, т. 5, сс. 219-255 Îòòèñêè äîñòóïíû íåïîñðåäñòâåííî îò èçäàòåëÿ Ôîòîêîïèðîâàíèå ðàçðåøåíî òîëüêî â ñîîòâåòñòâèè ñ ëèöåíçèåé  2004 ÈÌÔ (Èíñòèòóò ìåòàëëîôèçèêè èì. Ã. Â. Êóðäþìîâà ÍÀÍ Óêðàèíû) Íàïå÷àòàíî â Óêðàèíå.

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Model approach to evaluate particle size effects in electrocatalysis: preparation and properties of Pt nanoparticles supported on GC and HOPG

Cited by 199 publications

References 33 publications

Influence of Particle Size on the Properties of Pt–Ru∕C Catalysts Prepared by a Microemulsion Method

Influence of Particle Size on the Properties of Pt–Ru∕C Catalysts Prepared by a Microemulsion Method

The electrooxidation of small organic molecules on platinum nanoparticles supported on gold: influence of platinum deposition procedure

Nanoscale States in Metals, Alloys, and Intermetallic Compounds: Methods of Manufacture, Structure, Properties

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