scholarly journals Direct synthesis of platinum nanodots in ZIF-8/Fe3O4 core–shell hybrid nanoparticles

RSC Advances ◽  
2017 ◽  
Vol 7 (50) ◽  
pp. 31239-31243 ◽  
Author(s):  
Sanghee Lee ◽  
Changyong Yim ◽  
Sangmin Jeon
Keyword(s):  
Catalytic Activity ◽  
Direct Synthesis ◽  
Reducing Agents ◽  
Hybrid Nanoparticles ◽  
Core Shell ◽  
High Catalytic Activity ◽  
Fe3o4 Core

Platinum nanodots were synthesized inside ZIF-8/Fe3O4 core–shell hybrid nanoparticles without additional reducing agents, which showed high catalytic activity for the reduction of 4-nitrophenol.

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.

Towards rational design of core–shell catalytic nanoreactor with high performance catalytic hydrogenation of levulinic acid

2016 ◽  
Vol 6 (13) ◽  
pp. 5102-5115 ◽  
Author(s):  
Biplab Banerjee ◽  
Ramana Singuru ◽  
Sudipta K. Kundu ◽  
Karnekanti Dhanalaxmi ◽  
Linyi Bai ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Hydrogenation ◽  
Levulinic Acid ◽  
High Performance ◽  
Rational Design ◽  
Core Shell ◽  
High Catalytic Activity

Core–shell catalytic nanoreactor was designed, exhibiting high catalytic activity for levulinic acid hydrogenation.

Hollow and Core–Shell Nanostructure Co3O4 Derived from a Metal Formate Framework toward High Catalytic Activity of CO Oxidation

2018 ◽  
Vol 1 (2) ◽  
pp. 800-806 ◽  
Author(s):  
Chi Zhang ◽  
Li Zhang ◽  
Guancheng Xu ◽  
Xin Ma ◽  
Jinling Xu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Core Shell ◽  
High Catalytic Activity ◽  
Metal Formate

Thermally stable sandwich-type catalysts of Pt nanoparticles encapsulated in CeO2 nanorod/CeO2 nanoparticle core/shell supports for methane oxidation at high temperatures

RSC Advances ◽  
2016 ◽  
Vol 6 (46) ◽  
pp. 40323-40329 ◽  
Author(s):  
Zhiyun Zhang ◽  
Jing Li ◽  
Wei Gao ◽  
Zhaoming Xia ◽  
Yuanbin Qin ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
Methane Oxidation ◽  
High Temperatures ◽  
Pt Nanoparticles ◽  
Core Shell ◽  
High Catalytic Activity ◽  
Thermally Stable ◽  
Sandwich Type ◽  
Nanoparticle Core

A sandwich-type Pt nanocatalyst encapsulated ceria-based core–shell catalyst (CNR@Pt@CNP) was designed and synthesized, which exhibited high catalytic activity and remarkably thermal-stability at high temperatures up to 700 °C.

A Core-Shell Nanoporous Pt-Cu Catalyst with Tunable Composition and High Catalytic Activity

2013 ◽  
Vol 23 (33) ◽  
pp. 4156-4162 ◽  
Author(s):  
Xingbo Ge ◽  
Luyang Chen ◽  
Jianli Kang ◽  
Takeshi Fujita ◽  
Akihiko Hirata ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Core Shell ◽  
High Catalytic Activity ◽  
Cu Catalyst

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.

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