Supported organoactinide complexes as heterogeneous catalysts. A kinetic and mechanistic study of facile arene hydrogenation

1992 ◽  
Vol 114 (26) ◽  
pp. 10358-10368 ◽  
Author(s):  
Moris S. Eisen ◽  
Tobin J. Marks
Keyword(s):  
Heterogeneous Catalysts ◽  
Mechanistic Study ◽  
Arene Hydrogenation

ChemInform Abstract: Efficient and Practical Arene Hydrogenation by Heterogeneous Catalysts under Mild Conditions.

ChemInform ◽  
2009 ◽  
Vol 40 (48) ◽  
Author(s):  
Tomohiro Maegawa ◽  
Akira Akashi ◽  
Kiichiro Yaguchi ◽  
Yohei Iwasaki ◽  
Masahiro Shigetsura ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Mild Conditions ◽  
Arene Hydrogenation

Mechanistic study and catalyst development for selective carbon monoxide methanation

2015 ◽  
Vol 5 (6) ◽  
pp. 3061-3070 ◽  
Author(s):  
S. Tada ◽  
R. Kikuchi
Keyword(s):  
Carbon Monoxide ◽  
Reaction Mechanism ◽  
Heterogeneous Catalysts ◽  
Mechanistic Study ◽  
Co Methanation ◽  
Catalyst Development ◽  
Selective Co Methanation

As for selective CO methanation over heterogeneous catalysts, numerous investigations of the reaction mechanism and catalyst development are reviewed.

scholarly journals Glass Surface as Strong Base, ‘Green’ Heterogeneous Catalyst and Degradation Reagent

2021 ◽  
Author(s):  
Yangjie Li ◽  
Kai-Hung Huang ◽  
Nicolás Morato ◽  
R. Graham Cooks
Keyword(s):  
Chemical Reactions ◽  
Heterogeneous Catalysts ◽  
Desorption Electrospray Ionization ◽  
Mechanistic Study ◽  
Ionization Mass ◽  
Systematic Screening ◽  
Strong Base ◽  
Low Concentrations ◽  
Conjugate Bases ◽  
Glass Surfaces

Systematic screening of accelerated chemical reactions at solid/solution interfaces has been carried out in high-throughput fashion using desorption electrospray ionization mass spectrometry and it provides evidence that glass surfaces accelerate various base-catalyzed chemical reactions. The reaction types include elimination, solvolysis, condensation and oxidation, whether or not the substrates are pre-charged. In a detailed mechanistic study, we provide evidence using nanoESI showing that glass surfaces can act as strong bases and convert protic solvents into their conjugate bases which then act as bases/nucleophiles when participating in chemical reactions. In aprotic solvents such as acetonitrile, glass surfaces act as ‘green’ heterogeneous catalysts that can be recovered and reused after simple rinsing. Besides their use in organic reaction catalysis, glass surfaces are also found to act as degradation reagents for phospholipids with increasing extents of degradation occuring at low concentrations. This finding suggests that the storage of base/nucleophile-labile compounds or lipids in glass containers should be avoided. <br>

scholarly journals Glass Surface as Strong Base, ‘Green’ Heterogeneous Catalyst and Degradation Reagent

2021 ◽  
Author(s):  
Yangjie Li ◽  
Kai-Hung Huang ◽  
Nicolás Morato ◽  
R. Graham Cooks
Keyword(s):  
Chemical Reactions ◽  
Heterogeneous Catalysts ◽  
Desorption Electrospray Ionization ◽  
Mechanistic Study ◽  
Ionization Mass ◽  
Systematic Screening ◽  
Strong Base ◽  
Low Concentrations ◽  
Conjugate Bases ◽  
Glass Surfaces

Systematic screening of accelerated chemical reactions at solid/solution interfaces has been carried out in high-throughput fashion using desorption electrospray ionization mass spectrometry and it provides evidence that glass surfaces accelerate various base-catalyzed chemical reactions. The reaction types include elimination, solvolysis, condensation and oxidation, whether or not the substrates are pre-charged. In a detailed mechanistic study, we provide evidence using nanoESI showing that glass surfaces can act as strong bases and convert protic solvents into their conjugate bases which then act as bases/nucleophiles when participating in chemical reactions. In aprotic solvents such as acetonitrile, glass surfaces act as ‘green’ heterogeneous catalysts that can be recovered and reused after simple rinsing. Besides their use in organic reaction catalysis, glass surfaces are also found to act as degradation reagents for phospholipids with increasing extents of degradation occuring at low concentrations. This finding suggests that the storage of base/nucleophile-labile compounds or lipids in glass containers should be avoided. <br>

Comparison of Cu-ZSM-5 Zeolites and Cu-MOF-505 Metal-Organic Frameworks as Heterogeneous Catalysts for the Mukaiyama Aldol Reaction: A DFT Mechanistic Study

ChemPhysChem ◽  
2013 ◽  
Vol 14 (5) ◽  
pp. 923-928 ◽  
Author(s):  
Sudarat Yadnum ◽  
Saowapak Choomwattana ◽  
Pipat Khongpracha ◽  
Jakkapan Sirijaraensre ◽  
Jumras Limtrakul
Keyword(s):  
Heterogeneous Catalysts ◽  
Aldol Reaction ◽  
Metal Organic Frameworks ◽  
Mechanistic Study ◽  
Mukaiyama Aldol Reaction ◽  
Mukaiyama Aldol ◽  
Metal Organic

Efficient and Practical Arene Hydrogenation by Heterogeneous Catalysts under Mild Conditions

2009 ◽  
Vol 15 (28) ◽  
pp. 6953-6963 ◽  
Author(s):  
Tomohiro Maegawa ◽  
Akira Akashi ◽  
Kiichiro Yaguchi ◽  
Yohei Iwasaki ◽  
Masahiro Shigetsura ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Mild Conditions ◽  
Arene Hydrogenation

What catalysis needs from the electron microscopist

1988 ◽  
Vol 46 ◽  
pp. 694-695
Author(s):  
Alexis T. Bell
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Catalyst Deactivation ◽  
Surface Composition ◽  
Internal Surface ◽  
Active Phase ◽  
Atomic Scale ◽  
Metal Catalyst ◽  
Internal Surface Area ◽  
Porous Support

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.

Electron holography of catalysts

1995 ◽  
Vol 53 ◽  
pp. 416-417
Author(s):  
A. K. Datye ◽  
D. S. Kalakkad ◽  
L. F. Allard ◽  
E. Völkl
Keyword(s):  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Scale ◽  
Nano Particles ◽  
Phase Image ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Phase Information ◽  
Particle Structure

The active phase in heterogeneous catalysts consists of nanometer-sized metal or oxide particles dispersed within the tortuous pore structure of a high surface area matrix. Such catalysts are extensively used for controlling emissions from automobile exhausts or in industrial processes such as the refining of crude oil to produce gasoline. The morphology of these nano-particles is of great interest to catalytic chemists since it affects the activity and selectivity for a class of reactions known as structure-sensitive reactions. In this paper, we describe some of the challenges in the study of heterogeneous catalysts, and provide examples of how electron holography can help in extracting details of particle structure and morphology on an atomic scale.Conventional high-resolution TEM imaging methods permit the image intensity to be recorded, but the phase information in the complex image wave is lost. However, it is the phase information which is sensitive at the atomic scale to changes in specimen thickness and composition, and thus analysis of the phase image can yield important information on morphological details at the nanometer level.

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