Oxide Films as Catalytic Materials and Models of Real Catalysts

Freund, Hans‐Joachim

doi:10.1002/9783527640171.ch7

Cited by 7 publications

(7 citation statements)

References 149 publications

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“…These are the focus of this paper. These can be prepared in two dimensions either by further modifications of a single crystal in order to introduce supported nanoparticles, [3][4][5] or else by separate preparation of 2D nanoparticle samples using wet synthesis protocols and subsequent deposition on a 2D substrate such as a silicon wafer, for instance by Langmuir Blodgett deposition. [6] They can also be applied by deposition of the colloidal nanoparticles on supporting oxide materials to yield 3D structures, directly analogous to industrial type catalysts, but prepared with precise control over the nanoparticle structure independently of the step used to support the nanoparticles on the oxide.…”

Section: Nanoparticle Synthesis As a Route To Catalystsmentioning

confidence: 99%

Conquering Catalyst Complexity: Nanoparticle Synthesis and Instrument Development for Molecular and Atomistic Characterisation Under In Situ Conditions

Somorjai

Beaumont

2015

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. (2015) 'Conquering catalyst complexity : nanoparticle synthesis and instrument development for molecular and atomistic characterisation under in situ conditions.', Topics in catalysis., 58 (10). pp. 560-572. Further information on publisher's website:http://dx.doi.org/10.1007/s11244-015- Publisher's copyright statement:The nal publication is available at Springer via http://dx.doi.org/10.1007/s11244-015-0398-5Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. resolution in situ techniques with atomically and molecularly well-defined nanoparticle catalysts to achieve this goal. In particular we focus on mono-dispersed metal nanoparticles in the 0.8 -10 nm range with precise size distribution provided by modern colloidal synthetic techniques. These have been used in conjunction with a range of in situ techniques for understanding the complexity of a number of catalytic phenomena. Drawing on the nanoparticle size discrimination afforded by this approach, most metal nanoparticle catalysed covalent bond making/breaking reactions are identified as being structure sensitive, even when that was previously not thought to be the case. Small nanoparticles, below 2 nm, have been found to have changes of electronic structure that give rise to high oxidation state clusters under reaction conditions. These have been utilized to heterogenize typically homogeneous catalytic reactions using metal nanoclusters in the range of 40 atoms or less to carry out reactions on their heterogenized surfaces that would typically be expected only to occur at the higher oxidation state metal centre of a homogeneous organometallic catalyst. The combination of in-situ techniques and highly controlled metal nanoparticle structure also allows valuable insights to be achieved in understanding the mechanisms of multicomponent catalysts, catalysis occurring in different fluid phases and phenomena occurring at the metal-oxide interface.

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Section: Nanoparticle Synthesis As a Route To Catalystsmentioning

confidence: 99%

Conquering Catalyst Complexity: Nanoparticle Synthesis and Instrument Development for Molecular and Atomistic Characterisation Under In Situ Conditions

Somorjai

Beaumont

2015

Top Catal

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“…The use of nanotechnology to develop advanced materials for use as model catalysts has been a key recent development in studying heterogeneous catalysis. 14,15,16,17 The advantage gained is that numerous model structures with good control over metal particle size, shape, composition and metal oxide structure and porosity can be made. 18 The uniformity that can be obtained is invaluable in two ways.…”

Section: Introductionmentioning

confidence: 99%

“…Such effects include particle size, or interaction of the metal or reactants with the oxide support. Nanomaterial model catalysts have generally been generated in two modes as shown -some based on atomic and molecular deposition on well-defined substrates 16 and others using colloidal wet chemistry to generate well defined structures that can be built 'bottom up' into the desired catalyst structure. 18 Careful design of the oxide support can even be used to produce hierarchical structures with control at different lengthscales.…”

Section: Introductionmentioning

confidence: 99%

Recent developments in the application of nanomaterials to understanding molecular level processes in cobalt catalysed Fischer–Tropsch synthesis

Beaumont

2014

Phys. Chem. Chem. Phys.

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“…Metal oxide surfaces and thin films are subjects of great interest because of their broad spectrum of technological applications in different areas [1]. Thin films of the transition metal oxides, such as iron oxides, are unique because in addition to their catalytic properties [2] they have magnetic applications [3]. Depending on their stoichiometry and structure, the catalytic and magnetic properties of these oxides can vary significantly.…”

Section: Introductionmentioning

confidence: 99%

“…Fig.4. LEED patterns and STM images (400x400 nm2 , middle and 100x100 nm 2 , bottom) for iron oxide films grown on Pt(111) by oxidation of iron monolayers. The columns corresponds to the nominal oxide thickness of 3 ML, 4 ML, 5 ML and 7 ML, from left to right, respectively.…”

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confidence: 99%

Growth and electronic and magnetic structure of iron oxide films on Pt(111)

et al. 2012

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Ultrathin (111)-oriented polar iron oxide films were grown on a Pt(111) single crystal either by the reactive deposition of iron or oxidation of metallic iron monolayers. These films were characterized using low energy electron diffraction, scanning tunneling microscopy and conversion electron Mossbauer spectroscopy. The reactive deposition of Fe led to the island growth of Fe 3 O 4 , in which the electronic and magnetic properties of the bulk material were modulated by superparamagnetic size effects for thicknesses below 2 nm, revealing specific surface and interface features. In contrast, the oxide films with FeO stoichiometry, which could be stabilized as thick as 4 nm under special preparation conditions, had electronic and magnetic properties that were very different from their bulk counterpart, wüstite. Unusual long range magnetic order appeared at room temperature for thicknesses between three and ten monolayers, the appearance of which requires severe structural modification from the rock-salt structure. PACS: 68.47.Gh Oxide surfaces, 68.55.-a Thin film structure and morphology, 75.70.Ak Magnetic properties of monolayers and thin films, 81.15.-z Methods of deposition of films and coatings; film growth and epitaxy, 82.80.Ej X-ray, Mössbauer, and other γ-ray spectroscopic analysis methods

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Oxide Films as Catalytic Materials and Models of Real Catalysts

Cited by 7 publications

References 149 publications

Conquering Catalyst Complexity: Nanoparticle Synthesis and Instrument Development for Molecular and Atomistic Characterisation Under In Situ Conditions

Conquering Catalyst Complexity: Nanoparticle Synthesis and Instrument Development for Molecular and Atomistic Characterisation Under In Situ Conditions

Recent developments in the application of nanomaterials to understanding molecular level processes in cobalt catalysed Fischer–Tropsch synthesis

Growth and electronic and magnetic structure of iron oxide films on Pt(111)

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