1991

DOI: 10.1021/j100177a018

|View full text |Cite

|

Sign up to set email alerts

|

Evidence for low-pressure catalysis in the gas phase by a naked metal cluster: the growth of benzene precursors on iron (Fe4+)

Manfred P. Irion²,

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Internal Proton Transfer In Malonaldehyde2

Discussion1

Dft-gga Simulations Of Hipco1

Citation Types

Supporting

2

Mentioning

55

Contrasting

0

Unclassified

1

Year Published

1992

1992

2006

2006

Publication Types

Select...

Article6

Book2

Relationship

Self Cite1

Independent7

Authors

Journals

Cited by 108 publications

(58 citation statements)

References 1 publication

Supporting

2

Mentioning

55

Contrasting

0

Unclassified

1

Order By: Relevance

“…The composition of the formed cluster ions can be varied with the initial molar ratio of HAuCl 4 to AgTFA in the solid phase. This makes possible to tailor the compositions of the mixed cluster ions for a specific demand.…”

Section: Discussionmentioning

confidence: 99%

“…Besides fundamental interest, extensive study of such species over the past decades has been motivated by their potential technological application in areas such as optics [1,2], catalysis [3,4], and photography [5]. Metal clusters containing two different kinds of atoms, that is, binary clusters or nano-alloys have received growing interest since they are regarded as small scale precursors of bulk alloys.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Bimetallic silver-gold clusters by matrix-assisted laser desorption/ionization

¹

,

²

,

³

et al. 2004

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Pure gold clusters (Au n ϩ ) were produced up to the cluster size of n ϭ 100 by matrix-assisted laser desorption/ionization (MALDI). The mass spectrum of the resulting clusters showed alteration in the ion intensity at odd-even clusters size. On the other hand, intensity drops at cluster size predicted by the jellium model theory was also observed. Positively and negatively charged bimetallic silver-gold clusters were produced under MALDI conditions from the mixture of HAuCl 4 /silver trifluoroacetate and the 2-(4-hydroxyphenylazo)benzoic acid (HABA) matrix. A linear correlation was found between the intensity ratio of Au n Ag m ϩ to Au nϩ1 Ag mϪ1 ϩ cluster ions and the molar ratio of the gold to silver salt. It was observed that the composition and the distribution of the clusters can be varied with the molar ratio of the silver and gold salts. It was also found that the resulting cluster sizes obey the lognormal distribution. The variation of the atom types building up the cluster and/or the composition, as well as the size of the cluster offers various possibilities to engineer their properties for specific technological and scientific demands. However, to achieve these specific goals much information on the physical and chemical properties of the clusters as the function of their composition and size should be gained. Mass spectrometric methods provide a unique experimental tool for the investigation of the electronic and geometric properties of small-size metal clusters [6].In the past decades several methods were explored to induce gas-phase generation of metal clusters, and most of these techniques were based on the evaporation of metals by heating [7,8], or using laser ablation [9 -11] and ion-bombardment [12][13][14][15]. The production and investigation of binary silver-gold [2,16,17] and those of the pure silver [12][13][14]18] and gold clusters [12,13] has been reported by several research groups. However, in contrast to the information available on the pure silver and gold clusters, only very limited experimental [16,17] and theoretical studies [19] on the properties of small size silver-gold clusters have been reported. Recently, the generation of silver-cluster ions in matrix-assisted laser desorption/ionization (MALDI) [20,21] was reported using silver salts and various matrixes [22][23][24]. In a previous paper [24] we have shown that both positively and negatively charged silver clusters up to the size of 200 can be effectively produced from silver ions under MALDI conditions. It was noted that considerable reduction of Ag ϩ takes place in the plume and the matrices enhance the formation of silver clusters. As a continuation of our work, we utilized this method for the generation of pure gold clusters and for the production of mixed binary goldsilver clusters. To our best knowledge we are the first to apply the MALDI method to produce pure gold and bimetallic Au-Ag cluster ions. The present report shows that the resulting distribution of the binary gold-silver clusters can be effectively chan...

“…The composition of the formed cluster ions can be varied with the initial molar ratio of HAuCl 4 to AgTFA in the solid phase. This makes possible to tailor the compositions of the mixed cluster ions for a specific demand.…”

Section: Discussionmentioning

confidence: 99%

“…Besides fundamental interest, extensive study of such species over the past decades has been motivated by their potential technological application in areas such as optics [1,2], catalysis [3,4], and photography [5]. Metal clusters containing two different kinds of atoms, that is, binary clusters or nano-alloys have received growing interest since they are regarded as small scale precursors of bulk alloys.…”

mentioning

confidence: 99%

Bimetallic silver-gold clusters by matrix-assisted laser desorption/ionization

¹

,

²

,

³

et al. 2004

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Pure gold clusters (Au n ϩ ) were produced up to the cluster size of n ϭ 100 by matrix-assisted laser desorption/ionization (MALDI). The mass spectrum of the resulting clusters showed alteration in the ion intensity at odd-even clusters size. On the other hand, intensity drops at cluster size predicted by the jellium model theory was also observed. Positively and negatively charged bimetallic silver-gold clusters were produced under MALDI conditions from the mixture of HAuCl 4 /silver trifluoroacetate and the 2-(4-hydroxyphenylazo)benzoic acid (HABA) matrix. A linear correlation was found between the intensity ratio of Au n Ag m ϩ to Au nϩ1 Ag mϪ1 ϩ cluster ions and the molar ratio of the gold to silver salt. It was observed that the composition and the distribution of the clusters can be varied with the molar ratio of the silver and gold salts. It was also found that the resulting cluster sizes obey the lognormal distribution. The variation of the atom types building up the cluster and/or the composition, as well as the size of the cluster offers various possibilities to engineer their properties for specific technological and scientific demands. However, to achieve these specific goals much information on the physical and chemical properties of the clusters as the function of their composition and size should be gained. Mass spectrometric methods provide a unique experimental tool for the investigation of the electronic and geometric properties of small-size metal clusters [6].In the past decades several methods were explored to induce gas-phase generation of metal clusters, and most of these techniques were based on the evaporation of metals by heating [7,8], or using laser ablation [9 -11] and ion-bombardment [12][13][14][15]. The production and investigation of binary silver-gold [2,16,17] and those of the pure silver [12][13][14]18] and gold clusters [12,13] has been reported by several research groups. However, in contrast to the information available on the pure silver and gold clusters, only very limited experimental [16,17] and theoretical studies [19] on the properties of small size silver-gold clusters have been reported. Recently, the generation of silver-cluster ions in matrix-assisted laser desorption/ionization (MALDI) [20,21] was reported using silver salts and various matrixes [22][23][24]. In a previous paper [24] we have shown that both positively and negatively charged silver clusters up to the size of 200 can be effectively produced from silver ions under MALDI conditions. It was noted that considerable reduction of Ag ϩ takes place in the plume and the matrices enhance the formation of silver clusters. As a continuation of our work, we utilized this method for the generation of pure gold clusters and for the production of mixed binary goldsilver clusters. To our best knowledge we are the first to apply the MALDI method to produce pure gold and bimetallic Au-Ag cluster ions. The present report shows that the resulting distribution of the binary gold-silver clusters can be effectively chan...

“…We chose Fe 4 -, Fe 4 , and Fe 4 + clusters since the Fe 4 + cluster is known [19] to catalyze the growth of benzene from ethylene and cyclopropane in a low-pressure gas-phase process. The number of iron atoms in clusters formed in the HiPco process ranges from ~10 to ~300 and it is not clear if smaller iron clusters Fe 3 to Fe 10 can technologically be effective for the SWCNT growth because of different restrictions such as coalescence of small clusters.…”

Section: Dft-gga Simulations Of Hipcomentioning

confidence: 99%

All-Electron DFT Modeling of SWCNT Growth Initiation by Iron Catalyst

¹

,

²

,

³

2006

Computational Science – ICCS 2006

View full text Add to dashboard Cite

Abstract. Electronic and geometrical structures of Fe 4 C n (CO) m (n+m≤6) and Fe 4 C n (n=7-16) clusters along with their singly negatively and positively charged ions are computed using density functional theory with generalized gradient approximation (DFT-GGA). Isomers with CO bonded directly to the iron atoms and bonded to a carbon atom chemisorbed on the cluster surface are optimized for the Fe 4 C 2 CO, Fe 4 C 2 (CO) 2 , Fe 4 C 3 CO, and Fe 4 C 4 CO series. The computed total energies are used to estimate the energetics of the Boudouard disproportionation reactions

“…Acetylene oligomerization with Fe + Cyclotrimerization of acetylene in the gas phase induced by transition metal atoms (35)(36)(37), clusters (38)(39)(40) and surfaces (41~45) is being studied intensively, but the reaction mechanism is still unknown. In particular, Irion et al (38)(39)(40) showed experimental evidence that when ethylene reacts with Fe4 + , a product of stoechiometry Fe^CeHe)" 1 ' is formed through dehydrogenation of ethylene, and benzene is released during the collision-induced dissociation experiment.…”

Section: Internal Proton Transfer In Malonaldehydementioning

confidence: 99%

“…In particular, Irion et al (38)(39)(40) showed experimental evidence that when ethylene reacts with Fe4 + , a product of stoechiometry Fe^CeHe)" 1 ' is formed through dehydrogenation of ethylene, and benzene is released during the collision-induced dissociation experiment. In the proposed mechanism, it is acetylene rather than ethylene that is adsorbed on the Fe4 + cluster.…”

Section: Internal Proton Transfer In Malonaldehydementioning

confidence: 99%

Performance of Density Functional for Transition States

¹

,

²

,

³

et al. 1999

ACS Symposium Series

View full text Add to dashboard Cite

An overview of the performance of GGA, hybrid and LAP density functionals for transition states in a variety of benchmark systems is given. Examples, such as hydrogen abstraction and intramolecular proton transfer in malonaldehyde, illustrate the difficulties which even the most advanced density functionals meet in describing transition states. Comparisons are also reported for the oligomerization of acetylene Fe(C 2 H 2 ) + 2 --> Fe(C 4 H 4 ) + .Advances in computational techniques and the vast experience of the past decades have allowed an understanding of catalytic reactions at a very detailed level, involving full geometry optimization, characterization of transition states (TS) and reaction intermediates (1-3). The contemporary methods of density functional theory (DFT), especially with the latest progress in the development of efficient exchange-correlation (XC) functionals, appear rather successful in these cases, embodying a large amount of electron correlation at a much lower computational cost (1-3). However, in some cases the reaction path and especially the structure and the energy of the TS may present a stringent test for the existing approximate XC functionals. A typical example is the hydrogen abstraction reaction going through one of the seemingly simplest TS structures, a linear three-atomic complex. The correct reproduction of the energy barrier for this reaction turns out to be a very difficult task not only for approximate DFT methods but also for Hartree-Fock (HF) and most of the post-HF ab initio methods (4,5). In this chapter we shed some light on why this linear three-center TS structure is so difficult to describe.Another big challenge for DFT and post-HF methods is the correct description of inter-molecular and intra-molecular proton transfer (PT) energetics. The energy barrier for the internal proton transfer (IPT) in malonaldehyde is particularly difficult

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Product

Browser Extension Assistant by scite Citation Statement Search Reference Check Visualizations Dashboards Explore Journals Explore Organizations Explore Funders Embedding Badge Embedding Citation Search Pricing

Resources

Blog Help & FAQ Accessibility Statement API Terms For Universities & Governments For Researchers For Publishers For Corporate, Pharma & Enterprise Author Marketing Become an Affiliate Get an organization trial or quote scite Data & Services

About

News & Press Careers Read our Paper Coverage

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Copyright © 2024 scite LLC. All rights reserved.

Made with 💙 for researchers

Part of the Research Solutions Family.