Boundary‐Layer Catalysis

Schwab, G.-M.

doi:10.1002/anie.196703751

Cited by 44 publications

(35 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…e Product selectivities in n-hexane reforming over 2.7 nm Pt nanoparticles supported on different kinds of oxide supports. f Product selectivities over mesoporous zeolites and Pt nanoparticle-supported zeolite catalysts in hydrogenative methylcyclopentane reforming (modified with permission from [69], copyright 1967 Wiley-VCH, [72], copyright 1994 Springer and [40,49,73,75], copyright 2013,2012,2014,2014 American Chemical Society) novel supports by using organic structure directing agents and inorganic hard-templates. By protecting a catalyst metal core and by providing functional properties, elaborate core/shell nanoparticles have also been designed, having various kinds of shells including mesoporous oxides, multiple metal layers, and MOFs.…”

Section: Discussionmentioning

confidence: 99%

“…In the 1960s, Schwab discovered that there was a active site at the oxide-metal interface [69]. In the methane oxidation reaction, he found out that Ag supported on ZnO catalysts had a much higher activity toward CO 2 than Ag or ZnO catalysts due to the catalytic promoter effect by an electron exchange between support and catalyst (Fig.…”

Section: Oxide-metal Interactionsmentioning

confidence: 99%

See 1 more Smart Citation

Nanocatalysis I: Synthesis of Metal and Bimetallic Nanoparticles and Porous Oxides and Their Catalytic Reaction Studies

Somorjai

2014

Catal Lett

135

View full text Add to dashboard Cite

In recent heterogeneous catalysis, much effort has been made in understanding how the size, shape, and composition of nanoparticles and oxide-metal interfaces affect catalytic performance at the molecular level. Recent advances in colloidal synthetic techniques enable preparing diverse metallic or bimetallic nanoparticles with welldefined size, shape, and composition and porous oxides as a high surface support. As nanoparticles become smaller, new chemical, physical, and catalytic properties emerge. Geometrically, as the smaller the nanoparticle the greater the relative number of edge and corner sites per unit surface of the nanoparticle. When the nanoparticles are smaller than a critical size (2.7 nm), finite-size effects such as a change of adsorption strength or oxidation state are revealed by changes in their electronic structures. By alloying two metals, the formation of heteroatom bonds and geometric effects such as strain due to the change of metal-metal bond lengths cause new electronic structures to appear in bimetallic nanoparticles. Ceaseless catalytic reaction studies have been discovered that the highest reaction yields, product selectivity, and process stability were achieved by determining the critical size, shape, and composition of nanoparticles and by choosing the appropriate oxide support. Depending on the pore size, various kinds of micro-, meso-, and macro-porous materials are fabricated by the aid of structure-directing agents or hardtemplates. Recent achievements for the preparation of versatile core/shell nanostructures composing mesoporous oxides, zeolites, and metal organic frameworks provide new insights toward nanocatalysis with novel ideas.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Oxide-metal Interactionsmentioning

confidence: 99%

Nanocatalysis I: Synthesis of Metal and Bimetallic Nanoparticles and Porous Oxides and Their Catalytic Reaction Studies

Somorjai

2014

Catal Lett

135

View full text Add to dashboard Cite

show abstract

“…These studies were initiated in the 1950's and 1960's and an explanation for this phenomenon is provided by the evidence of hot electron generation at metal surfaces [41] . It appears that when photons strike a metal surface in the femtosecond regime hot electrons generate and diffused into the metal before they can be equilibrated with lattice vibrations.…”

Section: The Active Sites At the Oxide Metal Interfacementioning

confidence: 99%

Colloid Science of Metal Nanoparticle Catalysts in 2D and 3D Structures. Challenges of Nucleation, Growth, Composition, Particle Shape, Size Control and Their Influence on Activity and Selectivity

2008

View full text Add to dashboard Cite

Recent breakthroughs in synthesis in nanosciences have achieved control of size and shapes of nanoparticles that are relevant for catalyst design. In this article, we review the advance of synthesis of nanoparticles, fabrication of two and three dimensional model catalyst system, characterization, and studies of activity and selectivity. The ability to synthesize monodispersed platinum and rhodium nanoparticles in the 1-10 nm range permitted us to study the influence of composition, structure, and dynamic properties of monodispersed metal nanoparticle on chemical reactivity and selectivity. We review the importance of size and shape of nanoparticles to determine the reaction selectivity in multi-path reactions. The influence of metal-support interaction has been studied by probing the hot electron flows through the metal-oxide interface in catalytic nanodiodes. Novel designs of nanoparticle catalytic systems are discussed.2

show abstract

“…It has been a longstanding observation in the field of heterogeneous catalysis that the oxide onto which the metal nanoparticles are deposited can dramatically change the activity and selectivity in certain reactions even though the oxide itself is not active in catalysis [50,51,52 ] . Recently studies, which detected hot electron formation at metal surfaces helped to explain these curious findings [53][54][55] .…”

Section: Oxide Metal Interfaces Are Catalytically Activementioning

confidence: 99%

Evolution of the surface science of catalysis from single crystals to metal nanoparticles under pressure

Somorjai

Park

2008

The Journal of Chemical Physics

View full text Add to dashboard Cite

Vacuum studies of metal single crystal surfaces using electron and molecular beam scattering revealed that the surface atoms relocate when the surface is clean (reconstruction) and when it is covered by adsorbates (adsorbate induced restructuring).It was also discovered that atomic steps and other low coordination surface sites are active for breaking chemical bonds (H-H, O=O, C-H, C=O and C-C) with high reaction probability. Investigations at high reactant pressures using sum frequency generation (SFG) -vibrational spectroscopy and high pressure scanning tunneling microscopy (HPSTM) revealed bond breaking at low reaction probability sites on the adsorbatecovered metal surface, and the need for adsorbate mobility for continued turnover. Since most catalysts (heterogeneous, enzyme and homogeneous) are nanoparticles, colloid synthesis methods were developed to produce monodispersed metal nanoparticles in the 1-10 nm range and controlled shapes to use them as new model catalyst systems in twodimensional thin film form or deposited in mesoporous three-dimensional oxides. Studies of reaction selectivity in multipath reactions (hydrogenation of benzene, cyclohexene and crotonaldehyde) showed that reaction selectivity depends on both nanoparticle size and shape. The oxide-metal nanoparticle interface was found to be an important catalytic site because of the hot electron flow induced by exothermic reactions like carbon monoxide oxidation.

show abstract

Boundary‐Layer Catalysis

Cited by 44 publications

References 0 publications

Nanocatalysis I: Synthesis of Metal and Bimetallic Nanoparticles and Porous Oxides and Their Catalytic Reaction Studies

Nanocatalysis I: Synthesis of Metal and Bimetallic Nanoparticles and Porous Oxides and Their Catalytic Reaction Studies

Colloid Science of Metal Nanoparticle Catalysts in 2D and 3D Structures. Challenges of Nucleation, Growth, Composition, Particle Shape, Size Control and Their Influence on Activity and Selectivity

Evolution of the surface science of catalysis from single crystals to metal nanoparticles under pressure

Contact Info

Product

Resources

About