scholarly journals Design and Synthesis of Hyperbranched Aromatic Polymers for Catalysis

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1344 ◽  
Author(s):  
Yuta Nabae ◽  
Masa-aki Kakimoto
Keyword(s):  
Heterogeneous Catalysts ◽  
Aerobic Oxidation ◽  
Review Article ◽  
Linear Polymers ◽  
Design And Synthesis ◽  
Oxidation Of Alcohols ◽  
Aromatic Polymers ◽  
Acid Catalyzed ◽  
Ether Ketone ◽  
Catalyzed Reactions

Aromatic polymers such as poly(ether sulfone), poly(ether ketone), and polyimide have been widely used in industry due to their thermal, mechanical, and chemical stabilities. Although their application to catalysis has been limited, the introduction of a hyperbranched architecture to such aromatic polymers is effective in developing catalytic materials that combine the advantages of homogenous and heterogeneous catalysts. This review article overviews the recent progress on the design and synthesis of hyperbranched aromatic polymers. Several acid catalyzed reactions and the aerobic oxidation of alcohols have been demonstrated using hyperbranched aromatic polymers as catalysts. The advantage of hyperbranched polymers against linear polymers is also discussed.

Platinum nanoparticles supported on polymeric ionic liquid functionalized magnetic silica: effective and reusable heterogeneous catalysts for the selective oxidation of alcohols in water

RSC Advances ◽  
2016 ◽  
Vol 6 (108) ◽  
pp. 106769-106777 ◽  
Author(s):  
Esmail Vessally ◽  
Mostafa Ghasemisarabbadeih ◽  
Zeynab Ekhteyari ◽  
Rahim Hosseinzadeh-Khanmiri ◽  
Ebrahim Ghorbani-Kalhor ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Platinum Nanoparticles ◽  
Heterogeneous Catalysts ◽  
Aerobic Oxidation ◽  
Secondary Alcohols ◽  
Polymeric Ionic Liquid ◽  
Oxidation Of Alcohols ◽  
Recyclable Catalysts ◽  
Magnetic Silica ◽  
Magnetic Silica Nanoparticles

In this manuscript, we demonstrate that functionalized magnetic silica nanoparticles are efficient and recyclable catalysts for the selective, aerobic oxidation of various primary and secondary alcohols.

Palladium complexes with 3-phenylpropylamine ligands: synthesis, structures, theoretical studies and application in the aerobic oxidation of alcohols as heterogeneous catalysts

RSC Advances ◽  
2015 ◽  
Vol 5 (124) ◽  
pp. 102424-102435 ◽  
Author(s):  
Kazem Karami ◽  
Nasrin Haghighat Naeini ◽  
Vaclav Eigner ◽  
Michal Dusek ◽  
Janusz Lipkowski ◽  
...  
Keyword(s):  
Palladium Nanoparticles ◽  
Heterogeneous Catalysts ◽  
Aerobic Oxidation ◽  
Palladium Complexes ◽  
Theoretical Studies ◽  
Oxidation Of Alcohols

Palladium complexes with 3-phenylpropylamine ligands were synthesized and characterized. Palladium nanoparticles were supported on cucurbit[6]uril and used as heterogeneous catalysts for the aerobic oxidation of alcohols to corresponding compounds.

Hyperbranched aromatic poly(ether ketone) functionalized with TEMPO as a heterogeneous catalyst for aerobic oxidation of alcohols

RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 1923-1928 ◽  
Author(s):  
Ying Shi ◽  
Yuta Nabae ◽  
Teruaki Hayakawa ◽  
Masa-aki Kakimoto
Keyword(s):  
Heterogeneous Catalyst ◽  
Aerobic Oxidation ◽  
Oxidation Of Alcohols ◽  
Ether Ketone

A hyperbranched aromatic poly(ether ketone) functionalized with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO/HBPEK) was investigated as a novel heterogeneous catalyst for aerobic oxidation of alcohols.

Porous Ru/RuOx/LDH as highly active heterogeneous catalysts for the aerobic oxidation of alcohols

2016 ◽  
Vol 40 (10) ◽  
pp. 8364-8370 ◽  
Author(s):  
Yu Tan ◽  
Dalei Sun ◽  
Libao Chen ◽  
Cheng Chao Li
Keyword(s):  
Catalytic Activity ◽  
Heterogeneous Catalysts ◽  
Aerobic Oxidation ◽  
Alcohol Oxidation ◽  
Highly Active ◽  
Oxidation Of Alcohols

Porous LDH supported Ru/RuOx nanocatalysts exhibited much better catalytic activity and stability than conventional Ru-based catalysts for alcohol oxidation.

The Effect of Hydrolysis Conditions on the Structure and Growth of Silicate Polymers

1984 ◽  
Vol 32 ◽  
Author(s):  
K. D. Keefer
Keyword(s):  
Colloidal Particles ◽  
Condensation Reaction ◽  
Linear Polymers ◽  
Branch Points ◽  
Angle Scattering ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Hydrolysis Conditions ◽  
Hydrolysis Of

ABSTRACTSmall angle scattering experiments have demonstrated that the structure of the silicate species produced by the hydrolysis of silicon alkoxides in non-aqueous solvents ranges from extended, weakly cross-linked polymers to highly condensed, colloidal particles. In contrast, inorganic, aqueous silicate solutions yield primarily colloidal particles because the silicate species have a number of different silanol sites available and the preferred condensation reaction is that of weakly condensed species with highly cross-linked branch sites, such as those on an amorphous silica surface. It is proposed that in the alkoxide systems, however, the hydrolysis reaction may control the number and type of silanol sites available for condensation. In acid catalyzed reactions, the rate of hydrolysis of a silicate tetrahedron tends to decrease as alkoxide groups are removed. This favors the production of silanol sites on the end of chains, thus generating linear polymers. In base catalyzed reactions, it is argued that each subsequent hydrolysis of a tetrahedron should proceed more rapidly than the previous one, producing numerous branch points which are the preferred sites for condensation.

scholarly journals Exploring the catalytic performance of a series of bimetallic MIL-100(Fe, Ni) MOFs

2019 ◽  
Vol 7 (35) ◽  
pp. 20285-20292 ◽  
Author(s):  
Mónica Giménez-Marqués ◽  
Andrea Santiago-Portillo ◽  
Sergio Navalón ◽  
Mercedes Álvaro ◽  
Valérie Briois ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
De Novo ◽  
Catalytic Performance ◽  
Mixed Metal ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

Stable mixed-metal FeIII/NiII MIL-100 MOFs have been synthesized de novo and have been explored as superior heterogeneous catalysts in acid catalyzed reactions, presenting superior performances.

scholarly journals Influence of Remaining Acid Sites of an Amorphous Aluminosilicate on the Oligomerization of n-Butenes after Impregnation with Nickel Ions

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1487
Author(s):  
Fabian Nadolny ◽  
Felix Alscher ◽  
Stephan Peitz ◽  
Ekaterina Borovinskaya ◽  
Robert Franke ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Acid Sites ◽  
Mesoporous Catalyst ◽  
Nickel Ions ◽  
Methyl Group ◽  
Before And After ◽  
Amorphous Aluminosilicate ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Group Migration

Highly linear octene isomers can be produced from n-butene on industrial scale by using Ni-containing aluminosilicates as heterogeneous catalysts. These catalysts can be prepared by impregnating an aluminosilicate with a Ni(II) salt solution. This leads to a competition between acid-catalyzed and nickel-catalyzed reactions. In this study it is shown that some octene isomers are exclusively formed via an acid-catalyzed mechanism as a result of methyl group migration at the surface of a mesoporous catalyst. Specifically, the isomers 4,4-dimethylhexene (4,4-DMH) and 3-ethyl-2-methylpentene (3E-2MP) exhibit a systematic correlation compared to the amount of 3,4-dimethylhexene (3,4-DMH) formed at acid sites. By analyzing the ratio of 4,4-DMH and/or 3E-2MP to 3,4-DMH in the product spectrum before and after impregnation with a nickel precursor, the extend of acid site covered by nickel ions can be evaluated.

scholarly journals Green Procedure for Aerobic Oxidation of Benzylic Alcohols with Palladium Supported on Iota-Carrageenan in Ethanol

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 498
Author(s):  
Eliraz Stamker ◽  
Oshrat Levy-Ontman ◽  
Adi Wolfson
Keyword(s):  
Heterogeneous Catalysts ◽  
Aerobic Oxidation ◽  
Active Species ◽  
Palladium Chloride ◽  
Benzylic Alcohols ◽  
Straightforward Method ◽  
Conversion Rates ◽  
Oxidation Of Alcohols ◽  
Inorganic Supports ◽  
Green Procedure

The search for selective heterogeneous catalysts for the aerobic oxidation of alcohols to ketones and aldehydes has drawn much attention in the last decade. To that end, different palladium-based catalysts have been proposed that use various organic and inorganic supports. In addition, supports that originate from a biological and renewable source that is also nontoxic and biodegradable were found to be superior. We heterogenized palladium chloride or acetate complexes with triphenylphosphine trisulfonate on iota-carrageenan xerogel by simple mixing of the complex and the polysaccharide in water. The resulting polysaccharide-catalyst mixture then underwent deep freeze and lyophilization, after which the catalyst was characterized by TEM, XPS and SEM-EDS and tested in aerobic oxidation. The new heterogeneous catalysts were successfully used for the first time in the aerobic oxidation of benzylic alcohols. Moreover, they were easily removed from the reaction mixture and recycled, yielding an increase in activity with each subsequent reuse. As determined by TEM and XPS, the reduction in palladium and the formation of nanoparticles during the reaction in ethanol yielded more active species and, therefore, higher conversion rates. A SEM-EDS analysis indicated that the palladium was thoroughly dispersed in the xerogel catalysts. Moreover, the xerogel catalyst was observed to undergo a structural change during the reaction. To conclude, the new heterogeneous catalyst was prepared by a simple and straightforward method that used a non-toxic, renewable and biodegradable support to yield an active, selective and recyclable heterogeneous system.

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