The decomposition of hydrogen peroxide catalysed by palladium-gold alloy wires

Eley, D. D.; Macmahon, D.M

doi:10.1016/0021-9797(72)90267-6

Cited by 17 publications

(26 citation statements)

References 18 publications

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“…The accumulation and speciation of oxygen on Pt surfaces has been a focus of debate in the literature due to its only partly understood relation to particle size 59−62 and effect on oxidation−reduction reactions. 81,94,95 The present study shows that larger particle size corresponds with higher surface oxygen content and enhanced fraction of chemisorbed oxygen. This is consistent with results from previous studies also showing that the accumulation of chemisorbed oxygen is enhanced on larger Pt particles, compared to smaller ones.…”

Section: Acs Applied Energy Materialssupporting

confidence: 55%

“…Results from previous research on nanosized platinum reveal two important and currently unresolved questions: (1) what oxygen species are present at the surfaces of nanosized platinum and in what abundance, and (2) how does surface oxygen change as a function of different synthesis conditions, sample treatments such as heating, and reaction conditions? Questions regarding surface oxygen composition are important for explaining the enigmatic variability in catalytic performance that has been reported for Pt nanocatalysts synthesized at different conditions. , For example, the formation of surface oxides due to heating , is known to affect the rate of reactions catalyzed by Pt. ,, New studies and detailed characterization of commercial Pt nanocatalysts are thus needed to determine fundamental properties of commercial Pt nanocatalysts, as well as how they change as a function of external conditions.…”

Section: Introductionmentioning

confidence: 99%

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Abundance and Speciation of Surface Oxygen on Nanosized Platinum Catalysts and Effect on Catalytic Activity

Serra-Maia

Winkler

Murayama

et al. 2018

ACS Appl. Energy Mater.

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Oxygen at the surface of nanosized platinum has a direct effect on catalytic activity of oxidation−reduction chemical reactions. However, the abundance and speciation of oxygen remain uncertain for platinum with different particle size and shape characteristics, which has hindered the development of fundamental property− activity relationships. We have characterized two commercially available platinum nanocatalysts known as Pt black and Pt nanopowder to evaluate the effects of synthesis and heating conditions on the physical and surface chemical properties, as well as on catalytic activity. Characterization using complementary electron microscopy, X-ray scattering, and spectroscopic methods showed that the larger average crystallite size of Pt nanopowder (23 nm) compared to Pt black (11 nm) corresponds with a 70% greater surface oxygen concentration. Heating the samples in air resulted in an increase in surface oxygen concentration for both nanocatalysts. Surface oxygen associated with platinum is in the form of chemisorbed oxygen, and no significant amounts of chemically bonded platinum oxide were found for any of the samples. The increase in surface oxygen abundance during heating depends on the initial size and surface oxygen content. Hydrogen peroxide decomposition rate measurements showed that larger particle size and higher surface chemisorbed oxygen correlate with enhanced catalytic activity. These results are particularly important for future studies that aim to relate the properties of platinum, or other metal nanocatalysts, with surface reactivity.

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Section: Acs Applied Energy Materialssupporting

confidence: 55%

Section: Introductionmentioning

confidence: 99%

Abundance and Speciation of Surface Oxygen on Nanosized Platinum Catalysts and Effect on Catalytic Activity

Serra-Maia

Winkler

Murayama

et al. 2018

ACS Appl. Energy Mater.

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“…Lest it be thought that the phenomenon of 'Compensation' in gold catalysis is the product of an over-heated imagination, the reader is referred to work on the decomposition of H 2 O 2 catalysed by Pd-Au alloy wires (18); the kinetic parameters show excellent 'Compensation' with activation energies from 8 to 92 kJ mol -1 . The range of E app values covered by variation of alloy composition and pre-treatment, and the proximity of all points to the line, makes this one of the most impressive 'Compensation' plots in the literature.…”

Section: A Probable Interpretationmentioning

confidence: 99%

Source of the catalytic activity of gold nanoparticles

Bond

2010

Gold Bull

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“…In an attempt to reconcile these results with the then prevailing rigid-band theory, Eley and Luetic attributed this discrepancy to different site requirements for the activated complex in the two reactions (3). Later on, in a study of hydrogen peroxide decomposition on gold-palladium alloys, it was realized that the correlation of activity with holes in the d-band of the alloys was not fully justified and that large changes in activity could result from differences in surface pretreatment and oxygen surface coverage (52). In gold-palladium alloys supported on alkaline earth carbonates, gold seemed to increase the catalytic efficiency in the hydrogen peroxide decomposition, in contrast to silver which acted as a catalyst poison (53,54).…”

Section: Palladium-goldmentioning

confidence: 99%

Gold in bimetallic catalysts

Schwank

1985

Gold Bull

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In spite ofits low intiinsic catalytic activity, gold can influence the activity and selectivity of group VIII metals, such as palladium, platinum and ruthenium. Gold-containing bimetallic catalysts have found important industsralapplications and rep resent an active researcharea forelucidatingthecorrelation between suifacestructureandcatalytic activity.Ina recent article in this journal the applications of elemental gold in heterogeneous catalysis were reviewed with emphasis on monometallic gold catalysts (1). In the present review, the application of gold as a component in bimetallic catalysts is discussed. Special attention is paid to examples of bimetallic catalysts where the addition of gold appears to increase the catalytic activity or significantly influence the selectivity of the catalyst.Early work on bimetallic catalysts aimed at correlating the catalytic behaviour and the electronic structure with alloy composition. Alloys of palladium, a group VIII metal having in excited states a partially unoccupied d-band, and gold with a completely filled d-band were studied (2 -6) and attempts were made to interpret the results on the basis of the rigid band theory.However, it turned out that the observed catalytic activities could not unambiguously be correlated with increasing occupancy of dbands in.the alloys as a function of gold content. More recently, strong arguments have been put forward in favour of localized effects in catalysis where the two metal components in an alloy retain more or less their individual electronic structures (7). Adding gold to an active group VIII metal makes it possible to study not only electronic but also structural effects in catalysis. In reactions which require certain ensembles or clusters of active metal atoms, the presence of gold atoms with intrinsically low catalytic activity can dilute or disrupt such ensembles of active surface atoms and thus cause precipitous drops in activity as a function of gold content. Under certain conditions, the gold induced changes in available active groupings of group VIII metal atoms can lead to different selectivities. Of course, it is not always possi bie to clearly disentangle structural from electronic or 'ligand' effects (8).The preparation of bimetallic catalysts is not restricted to metal components which are capable of forming solid solu tions over the full composition range, but can also include elements which have limited miscibility such as platinum and gold, or even complete immiscibility. An example of the Jatter type is the ruthenium-gold system. Bimetallic systems with limited bulk miscibility offer the intriguing opportunity of investigatingwhether the bulk miscibility limitations start to break down at very high metal dispersions. The term 'bimetallic clusters' (9) or 'bimetallic aggregates' has been coined to describe the as of yet not fully understood structures of the metal particles in these bimetallic catalysts.In the following, the effects of gold on the catalytic behaviour of palladium, platinum and ruthenium will b...

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The decomposition of hydrogen peroxide catalysed by palladium-gold alloy wires

Cited by 17 publications

References 18 publications

Abundance and Speciation of Surface Oxygen on Nanosized Platinum Catalysts and Effect on Catalytic Activity

Abundance and Speciation of Surface Oxygen on Nanosized Platinum Catalysts and Effect on Catalytic Activity

Source of the catalytic activity of gold nanoparticles

Gold in bimetallic catalysts

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