Influence of the lanthanide(iii) ion in {[Cu3Ln2(oda)6(H2O)6]·nH2O}n (LnIII: La, Gd, Yb) catalysts on the heterogeneous oxidation of olefins

2017 ◽  
Vol 7 (1) ◽  
pp. 231-242 ◽  
Author(s):  
P. Cancino ◽  
V. Paredes-García ◽  
C. Aliaga ◽  
P. Aguirre ◽  
D. Aravena ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Heterogeneous Oxidation ◽  
Oxidation Of Olefins ◽  
Oxydiacetic Acid

{[Cu3Ln2(oda)6(H2O)6]·nH2O}n (LnIII: La, Gd, Yb; odaH2: oxydiacetic acid) are reported as reusable heterogeneous catalysts in the oxidation of olefins.

Polymer immobilized tantalum(v)–amino acid complexes as selective and recyclable heterogeneous catalysts for oxidation of olefins and sulfides with aqueous H2O2

2019 ◽  
Vol 43 (44) ◽  
pp. 17251-17266
Author(s):  
Gangutri Saikia ◽  
Kabirun Ahmed ◽  
Chandrasee Rajkhowa ◽  
Mitu Sharma ◽  
Hiya Talukdar ◽  
...  
Keyword(s):  
Amino Acid ◽  
Heterogeneous Catalysts ◽  
Sulfide Oxidation ◽  
Reaction Conditions ◽  
Amino Acid Complexes ◽  
Highly Efficient ◽  
Recyclable Catalysts ◽  
Oxidation Of Olefins ◽  
Polymer Supported

Polymer supported peroxotantalate based heterogeneous catalysts served as highly efficient, selective and recyclable catalysts for alkene epoxidation and sulfide oxidation with green oxidant aqueous H2O2 under mild reaction conditions.

Dioxomolybdenum(vi) complex immobilized on ascorbic acid coated TiO2 nanoparticles catalyzed heterogeneous oxidation of olefins and sulfides

2015 ◽  
Vol 17 (1) ◽  
pp. 442-452 ◽  
Author(s):  
Maasoumeh Jafarpour ◽  
Abdolreza Rezaeifard ◽  
Mahboube Ghahramaninezhad ◽  
Fahimeh Feizpour
Keyword(s):  
Ascorbic Acid ◽  
Tio2 Nanoparticles ◽  
Environmentally Benign ◽  
Green Solvent ◽  
Heterogeneous Oxidation ◽  
Oxidation Of Sulfides ◽  
Oxidation Of Olefins ◽  
Epoxidation Of Olefins

TiO2/AA/MoO2 nanocomplex demonstrated desired activity and selectivity in the epoxidation of olefins and oxidation of sulfides to sulfoxides using H2O2 as an environmentally benign oxidant in ethanol as a green solvent.

scholarly journals Copper(II) complex of (±)trans-1,2-cyclohexanediamine azo-linked Schiff base ligand encapsulated in nanocavity of zeolite-Y for the catalytic oxidation of olefins

2016 ◽  
Vol 81 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Maryam Lashanizadegan ◽  
Sahar Shayegan ◽  
Marzieh Sarkheil
Keyword(s):  
Schiff Base ◽  
Schiff Base Ligand ◽  
Heterogeneous Catalysts ◽  
Zeolite Y ◽  
Schiff Base Complex ◽  
Reaction Conditions ◽  
Catalytic Behavior ◽  
Tert Butyl Hydroperoxide ◽  
Oxidation Of Olefins ◽  
Ft Ir

A Schiff base ligand derived from 4-(benzeneazo) salicylaldehyde and (?)trans-1,2-cyclohexanediamine (H2L) and its corresponding Cu(II) complex (CuL) has been synthesized and characterized by FT-IR, UV-VIS and 1H NMR. The copper Schiff base complex encapsulated in the nanopores of zeolite-Y (CuL-Y) by flexible ligand method and its encapsulation have been ensured by different studies. The homogeneous and its corresponding heterogeneous catalysts have been used for oxidation of different alkenes with tert-butyl hydroperoxide. Under the optimized reaction conditions, the oxidation of cyclooctene, cyclohexene, styrene and norbornene catalyzed by CuL gave 89, 63, 46 and 13% conversion, respectively. These olefins were oxidized efficiently with 50, 96, 96 and 92% conversion in the presence of CuL-Y, respectively. Comparison of the catalytic behavior of CuL and CuL-Y showed the higher catalytic activity and selectivity of the heterogeneous catalyst with respect to the homogenous one.

scholarly journals Heterogeneous Metal Catalysts for Oxidation Reactions

2014 ◽  
Vol 2014 ◽  
pp. 1-23 ◽  
Author(s):  
Md. Eaqub Ali ◽  
Md. Motiar Rahman ◽  
Shaheen M. Sarkar ◽  
Sharifah Bee Abd Hamid
Keyword(s):  
Heterogeneous Catalysts ◽  
Low Cost ◽  
Short Review ◽  
Oxidation Catalysis ◽  
Oxidation Reactions ◽  
Oxidation Catalysts ◽  
Heterogeneous Oxidation ◽  
Reference Guide ◽  
Current State ◽  
Selection Of

Oxidation reactions may be considered as the heart of chemical synthesis. However, the indiscriminate uses of harsh and corrosive chemicals in this endeavor are threating to the ecosystems, public health, and terrestrial, aquatic, and aerial flora and fauna. Heterogeneous catalysts with various supports are brought to the spotlight because of their excellent capabilities to accelerate the rate of chemical reactions with low cost. They also minimize the use of chemicals in industries and thus are friendly and green to the environment. However, heterogeneous oxidation catalysis are not comprehensively presented in literature. In this short review, we clearly depicted the current state of catalytic oxidation reactions in chemical industries with specific emphasis on heterogeneous catalysts. We outlined here both the synthesis and applications of important oxidation catalysts. We believe it would serve as a reference guide for the selection of oxidation catalysts for both industries and academics.

Copper based coordination polymers based on metalloligands: utilization as heterogeneous oxidation catalysts

2018 ◽  
Vol 47 (47) ◽  
pp. 16985-16994 ◽  
Author(s):  
Gulshan Kumar ◽  
Firasat Hussain ◽  
Rajeev Gupta
Keyword(s):  
Coordination Polymers ◽  
Heterogeneous Catalysts ◽  
Solvent Free ◽  
Oxidation Catalysts ◽  
Heterogeneous Oxidation ◽  
Benzyl Alcohols ◽  
Solvent Free Conditions ◽  
Epoxidation Of Olefins ◽  
Mediated Oxidation

This work presents two copper-based coordination polymers and their utilization as stable, reusable and heterogeneous catalysts for the epoxidation of olefins using O2 and for peroxide-mediated oxidation of benzyl alcohols under solvent-free conditions.

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.

Quantitative nano-characterization of heterogeneous catalysts

1995 ◽  
Vol 53 ◽  
pp. 398-399
Author(s):  
P.A. Crozier ◽  
M. Pan
Keyword(s):  
Heterogeneous Catalysts ◽  
Low Dose ◽  
Imaging Techniques ◽  
Structural Features ◽  
Catalyst Characterization ◽  
New Developments ◽  
Double Phase ◽  
Phase Systems ◽  
Dose Imaging

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.

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