Direct Synthesis and Catalytic Reactivity of Highly Ordered Large-Pore Methylaminopropyl-Functionalized SBA-15 Materials

2005 ◽  
Vol 58 (7) ◽  
pp. 507 ◽  
Author(s):  
Xueguang Wang ◽  
Soofin Cheng
Keyword(s):  
Catalytic Activity ◽  
Inorganic Salt ◽  
Direct Synthesis ◽  
Initial Mixture ◽  
Tetraethyl Orthosilicate ◽  
High Catalytic Activity ◽  
Amino Groups ◽  
Large Pore ◽  
Catalytic Reactivity ◽  
First Time

Highly ordered large-pore SBA-15 materials functionalized with a high loading of amino groups were synthesized for the first time by co-condensation of tetraethyl orthosilicate (TEOS) and [3-(methylamino)propyl]trimethoxysilane (MAPTMS) using an amphiphilic block copolymer. Addition of inorganic salt to the initial mixture greatly enhanced the mesostructure ordering and stability of the mesoporous materials. The materials thus obtained showed high catalytic activity and selectivity for the synthesis of flavanones by means of the Claisen–Schmidt condensation in the absence of solvent.

Catalytic activity of palladium-doped silver dilute nanoalloys for formate oxidation from a theoretical perspective

2019 ◽  
Vol 21 (40) ◽  
pp. 22598-22610 ◽  
Author(s):  
Nan Zhang ◽  
Fuyi Chen ◽  
Longfei Guo
Keyword(s):  
Catalytic Activity ◽  
Oxidation Reaction ◽  
Theoretical Perspective ◽  
Single Atom ◽  
High Catalytic Activity ◽  
Formate Oxidation ◽  
First Time ◽  
Single Atom Alloys

We demonstrate for the first time that the Pd1Ag single-atom alloys exhibit a high catalytic activity for formate oxidation reaction.

High Catalytic Activity of Pd Nanoparticles Synthesized from Green Alga Chlorella vulgaris in Buchwald-hartwig Synthesis of N-Aryl Piperazines

2019 ◽  
Vol 7 (1) ◽  
pp. 23-33
Author(s):  
Vaibhav Mishra ◽  
Anju Arya ◽  
Tejpal Singh Chundawat
Keyword(s):  
Catalytic Activity ◽  
Green Alga ◽  
Chlorella Vulgaris ◽  
Direct Synthesis ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
High Catalytic Activity ◽  
Pd Nanoparticle ◽  
Green Algal ◽  
Green Alga Chlorella

Background: The N-aryl piperazines are an important component of many drug products used for the treatment of malaria, depression, anxiety and Parkinson diseases. Buchwald-Hartwig amination is the latest and well-known reaction for Pd catalyzed direct synthesis of N-aryl piperazine from aryl halides. Although several Pd-ligand systems have already been discovered for this conversion, Pd nanoparticles are recently being used for this useful coupling reaction due to their recyclability and durability. Metal nanoparticles show enhanced catalytic activity compared to their bulk counterparts due to increased surface area at the edges and corners. The use of green algal extract in place of chemical ligands makes this process more environment-friendly and cost-effective. In this research, Pd nanoparticles synthesized using green alga C. Vulgaris were utilized as an alternative approach for the coupling reaction during the preparation of N-aryl piperazines. Methods: Synthesized Pd nanoparticles from C. Vulgaris were characterized by FTIR, SEM and XRD techniques. The catalytic activity of the synthesized nanoparticles was monitored for the synthesis of N-aryl piperazines by Buchwald-Hartwig reaction. The synthesized N-aryl piperazines were characterized by NMR, FTIR and mass analysis. Results: A very good catalytic activity of the synthesized Pd nanoparticles from green alga Chlorella vulgaris extract was observed. The green alga not only reduces the size of the Pd metal to nanoparticles but also acts as a green ligand for reduction of Pd(II) to Pd(0) during nanoparticle synthesis. Using this Pd nanoparticles-green ligand system, several N-aryl piperazines were synthesized in good to excellent yields. Reaction conditions for better conversion were optimized. The comparative advantage of the catalytic system with recently published works on Buchwald-Hartwig C-N coupling reaction is given. Recyclability and durability of the catalyst were explored and the results were found to be promising. A plausible mechanism of Pd nanoparticle catalyzed reaction is also proposed. Conclusion: Catalytic activity of the Pd nanoparticle synthesized from Chlorella vulagris in the synthesis of N-aryl piperazines by Buchwald-Hartwig reaction is reported first time to the best of our knowledge and understanding. The green approach of Pd catalyst to facilitate the reaction and its environmental impact is the main characteristic of the process.

Hollow silica nanostructures with small size Au nanoparticles for catalytic applications

RSC Advances ◽  
2016 ◽  
Vol 6 (92) ◽  
pp. 89057-89060 ◽  
Author(s):  
Lin Yao ◽  
Jong-Min Lee
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Au Nanoparticles ◽  
Tetraethyl Orthosilicate ◽  
High Catalytic Activity ◽  
Hollow Silica ◽  
Silica Nanostructures ◽  
Catalytic Applications

Hollow silica nanostructures synthesized using the silica precursors (3-aminopropyl) trimethoxysilane and tetraethyl orthosilicate provide support to small sized gold nanoparticles with a high catalytic activity for the reduction of 4-nitrophenol.

Direct synthesis, characterization of Cu-SBA-15 and its high catalytic activity in hydroxylation of phenol by H2O2

2005 ◽  
Vol 230 (1-2) ◽  
pp. 143-150 ◽  
Author(s):  
Lingping Wang ◽  
Aiguo Kong ◽  
Bo Chen ◽  
Hanming Ding ◽  
Yongkui Shan ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Direct Synthesis ◽  
High Catalytic Activity ◽  
Hydroxylation Of Phenol

High catalytic activity for water oxidation based on nanostructured nickel phosphide precursors

2015 ◽  
Vol 51 (58) ◽  
pp. 11626-11629 ◽  
Author(s):  
Ali Han ◽  
Huanlin Chen ◽  
Zijun Sun ◽  
Jun Xu ◽  
Pingwu Du
Keyword(s):  
Catalytic Activity ◽  
Noble Metal ◽  
Water Oxidation ◽  
Oxidation Catalysis ◽  
High Catalytic Activity ◽  
Nickel Phosphide ◽  
Catalyst Precursor ◽  
Metal Free ◽  
Water Oxidation Catalysis ◽  
First Time

For the first time, noble-metal-free nickel phosphide (Ni2P) was used as an excellent catalyst precursor for water oxidation catalysis.

Heterogeneous copper-catalyzed synthesis of diaryl sulfones

2021 ◽  
Author(s):  
Xinchi Gong ◽  
Zhengqi Shen ◽  
Ganghu Wang ◽  
Lingling Qu ◽  
Chunyin Zhu
Keyword(s):  
Catalytic Activity ◽  
Copper Nanoparticles ◽  
High Catalytic Activity ◽  
First Time

A carbon-supported copper nanoparticles (Cu-NP) with high catalytic activity for the synthesis of diaryl sulfonens is reported. For the first time, this Cu-NP was proved to be able to effectively...

Generation of a Highly Stable Reusable Biocatalyst by Entrapment of an Oligomeric Enzyme in Ultra-Large-Pore Mesoporous Silica

2015 ◽  
Vol 68 (3) ◽  
pp. 396 ◽  
Author(s):  
Christopher B. J. MacDonald ◽  
Matthew F. Tobin ◽  
Anna E. Morrison ◽  
Mary E. Tait ◽  
Godwin B. D'Cunha ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Catalytic Activity ◽  
Mesoporous Silica ◽  
Phenylalanine Ammonia Lyase ◽  
Pore Diameter ◽  
Mesoporous Silicas ◽  
High Catalytic Activity ◽  
Facile Synthesis ◽  
Prolonged Heating ◽  
Large Pore

Phenylalanine ammonia lyase (PAL, E.C.4.3.1.24), was entrapped in ultra-large-pore mesoporous silica (ULPS, 23 nm pore diameter) generating a recyclable, separable biocatalyst. The entrapped ULPS-PAL materials showed excellent stabilization, even after significant exposure to prolonged heating. Additionally, the entrapped ULPS-PAL materials showed extremely high catalytic activity in the deamination of l-phenylalanine to trans-cinnamic acid in aqueous solution and were recovered and recycled up to five times without any observable loss in activity. This approach is simple and capitalizes on the facile synthesis and easy recoverability of mesoporous silicas to generate a stable, reusable PAL-based biocatalyst.

Direct synthesis and catalytic activity of ordered large pore titanium-substituted spherical SBA-15 molecular sieves

2012 ◽  
Vol 106 (1) ◽  
pp. 245-256 ◽  
Author(s):  
Shengwen Chen ◽  
Changwen Ma ◽  
Minmin Qin ◽  
Haifeng Yang ◽  
Hongyong Xie ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Direct Synthesis ◽  
Large Pore

scholarly journals Direct synthesis of highly ordered large-pore functionalized mesoporous SBA-15 silica with methylaminopropyl groups and its catalytic reactivity in flavanone synthesis

2005 ◽  
Vol 85 (3) ◽  
pp. 241-251 ◽  
Author(s):  
Xueguang Wang ◽  
Yao-Hung Tseng ◽  
Jerry C.C. Chan ◽  
Soofin Cheng
Keyword(s):  
Direct Synthesis ◽  
Large Pore ◽  
Catalytic Reactivity
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