Mesoporous MCM-41 was used as a support for the uniform dispersion of ruthenium nanoparticles having an average particle size of 5 nm.The obtained nanocomposite,MCM-41-Ru,was characterized using inductively coupled pl...Mesoporous MCM-41 was used as a support for the uniform dispersion of ruthenium nanoparticles having an average particle size of 5 nm.The obtained nanocomposite,MCM-41-Ru,was characterized using inductively coupled plasma,transmission electron microscopy,energy dispersive X-ray analysis,X-ray diffraction,and BET surface area measurements.The material was employed as an efficient and recyclable catalyst in the ultrasound-assisted oxidation of arenes.It was observed that ultrasound irradiation in combination with KBrO3 as the oxidant,in the presence of MCM-41-Ru nanoparticles,accelerates the oxidation reaction to afford the desired products in good yields.The recovered catalyst retained activity for successive runs,with a continuous change in the nature of its active sites.展开更多
A Pd Schiff base complex was immobilized onto the surface of magnetic MCM‐41(Fe3O4@MCM‐41@Pd(0)‐P2C)as a novel,eco‐friendly,and recyclable heterogeneous nanocatalyst and fully characterized by FT‐IR,VSM,EDS,trans...A Pd Schiff base complex was immobilized onto the surface of magnetic MCM‐41(Fe3O4@MCM‐41@Pd(0)‐P2C)as a novel,eco‐friendly,and recyclable heterogeneous nanocatalyst and fully characterized by FT‐IR,VSM,EDS,transmission electron microscopy,scanning electron microscopy,thermogravimetric analyses,ICP‐OES,and X‐ray powder diffraction analysis.The Fe3O4@MCM‐41@Pd(0)‐P2C was investigated as a catalyst for the one‐pot Suzuki and Heck reactions in PEG as a green solvent to provide the target products in excellent yields.The main advantages of using this catalyst include a short reaction time,green reaction conditions,a simple experimental procedure,non‐use of hazardous organic solvents,low loading of the catalyst,and the ability to use various substrates.More importantly,the catalyst could be easily separated from the reaction mixture with the assistance of an external magnet and could be recovered and reused several times without significant loss of stability and activity.展开更多
In this study, magnetic core–shell structure Fe3O4@MCM-41 nanoparticles were synthesized with vesicles as soft templates. In the preparation, Fe Cl2 and tetraethy orthosilicate(TEOS) were selected as Fe processor and...In this study, magnetic core–shell structure Fe3O4@MCM-41 nanoparticles were synthesized with vesicles as soft templates. In the preparation, Fe Cl2 and tetraethy orthosilicate(TEOS) were selected as Fe processor and Si precursor, respectively. Stable vesicles first formed in 0.03 mol·L-11:2 mixture of anionic surfactant sodium dodecyl sulfate and cationic surfactant cetyltrimethyl ammonium bromide. Then, TEOS was added in the vesicle aqueous solution, leading to a highly dispersed solution. After high-temperature calcination, Fe3O4@MCM-41 nanoparticles were obtained. Their structure and morphology were characterized by Saturn Digisizer, transmission electron microscope and vibrating sample magneto-meter. The results indicate that the vesicles are spherical and their size could be tuned between 20 and 50 nm. The average grain diameter of synthesize magnetic core–shell Fe3O4@MCM-41 particles is 100–150 nm and most of them are in elliptical shape. The dispersion of magnetic particles is very good and magnetization values are up to 33.44 emu·g-1, which are superior to that of other Fe3O4 materials reported.展开更多
基金supported by the Research Council of University of Guilan
文摘Mesoporous MCM-41 was used as a support for the uniform dispersion of ruthenium nanoparticles having an average particle size of 5 nm.The obtained nanocomposite,MCM-41-Ru,was characterized using inductively coupled plasma,transmission electron microscopy,energy dispersive X-ray analysis,X-ray diffraction,and BET surface area measurements.The material was employed as an efficient and recyclable catalyst in the ultrasound-assisted oxidation of arenes.It was observed that ultrasound irradiation in combination with KBrO3 as the oxidant,in the presence of MCM-41-Ru nanoparticles,accelerates the oxidation reaction to afford the desired products in good yields.The recovered catalyst retained activity for successive runs,with a continuous change in the nature of its active sites.
基金Ilam University Research Council for partial financial support of this study
文摘A Pd Schiff base complex was immobilized onto the surface of magnetic MCM‐41(Fe3O4@MCM‐41@Pd(0)‐P2C)as a novel,eco‐friendly,and recyclable heterogeneous nanocatalyst and fully characterized by FT‐IR,VSM,EDS,transmission electron microscopy,scanning electron microscopy,thermogravimetric analyses,ICP‐OES,and X‐ray powder diffraction analysis.The Fe3O4@MCM‐41@Pd(0)‐P2C was investigated as a catalyst for the one‐pot Suzuki and Heck reactions in PEG as a green solvent to provide the target products in excellent yields.The main advantages of using this catalyst include a short reaction time,green reaction conditions,a simple experimental procedure,non‐use of hazardous organic solvents,low loading of the catalyst,and the ability to use various substrates.More importantly,the catalyst could be easily separated from the reaction mixture with the assistance of an external magnet and could be recovered and reused several times without significant loss of stability and activity.
基金Supported by the Natural Science Foundation of Heilongjiang Province(B201010)the Education Department of Heilongjiang Province(12511595)
文摘In this study, magnetic core–shell structure Fe3O4@MCM-41 nanoparticles were synthesized with vesicles as soft templates. In the preparation, Fe Cl2 and tetraethy orthosilicate(TEOS) were selected as Fe processor and Si precursor, respectively. Stable vesicles first formed in 0.03 mol·L-11:2 mixture of anionic surfactant sodium dodecyl sulfate and cationic surfactant cetyltrimethyl ammonium bromide. Then, TEOS was added in the vesicle aqueous solution, leading to a highly dispersed solution. After high-temperature calcination, Fe3O4@MCM-41 nanoparticles were obtained. Their structure and morphology were characterized by Saturn Digisizer, transmission electron microscope and vibrating sample magneto-meter. The results indicate that the vesicles are spherical and their size could be tuned between 20 and 50 nm. The average grain diameter of synthesize magnetic core–shell Fe3O4@MCM-41 particles is 100–150 nm and most of them are in elliptical shape. The dispersion of magnetic particles is very good and magnetization values are up to 33.44 emu·g-1, which are superior to that of other Fe3O4 materials reported.
