نتایج جستجو برای: catalyst free

تعداد نتایج: 553796  

2014
Ji-Sen Li Shun-Li Li Yu-Jia Tang Kui Li Lei Zhou Ning Kong Ya-Qian Lan Jian-Chun Bao Zhi-Hui Dai

The nitrogen (N), phosphorus (P) and sulphur (S) ternary-doped metal-free porous carbon materials have been successfully synthesized using MOFs as templates (denoted as NPS-C-MOF-5) for oxygen reduction reaction (ORR) for the first time. The influences of porous carbons from carbonizing different MOFs and carbonization temperature on ORR have been systematically investigated. Due to the synergi...

Journal: :organic chemistry research 2016
mohammad ali zolfigol meysam yarie

a highly efficient procedure for the synthesis of 1,8-dioxo-octahydroxanthenes under mild, green and solvent-free condition by using hosa as a dual role catalyst is described. this is the first report of catalytic activity of hosa.

Journal: :Chemical communications 2012
Simone Zanarini Svetoslava Vankova Simelys Hernandez Vijaykumar S Ijeri Marco Armandi Edoardo Garrone Barbara Bonelli Barbara Onida Paolo Spinelli

We report the first use of cobalt aluminophosphate (CoAPO5) as a water oxidation catalyst. A decrease in the overvoltage by about 0.2 V with respect to catalyst free FTO has been observed. Additionally, we show that CoAPO5, deposited on ITO or Pt, can also act as a photo-electro-catalyst, as it generates enhanced oxidation currents in the presence of light starting from a bias of +0.8 V vs. Ag/...

2014
Michaela Nebel Thomas Erichsen Wolfgang Schuhmann

Multidimensional shearforce-based constant-distance mode scanning electrochemical microscopy (4D SF/CD-SECM) was utilized for the investigation of the activity distribution of oxygen reduction catalysts. Carbon-supported Pt model catalyst powders have been immobilized in recessed microelectrodes and compared to a spot preparation technique. Microcavities serve as platform for the binder-free ca...

Journal: :Organic & biomolecular chemistry 2010
Subhash Banerjee Vagulejan Balasanthiran Ranjit T Koodali Grigoriy A Sereda

A novel, heterogeneous Pd-MCM-48 catalyst has been developed by encapsulating palladium nanoparticles into the cubic phase of mesoporous MCM-48 matrix at room temperature. The catalyst demonstrated excellent chemo- and regioselectivity for the hydrogenation of olefins at room temperature within 30-80 min. The turnover frequency for the hydrogenation is very high (4400 h(-1)). Interestingly, sel...

Kaolin-SO3H as a new solid acid is prepared via reaction of kaolin and chlorosulfonic acid. This natural based catalyst is very inexpensive and easy available. Imidazoles are an important class of heterocycles being the core fragment of different natural products and biological systems such as anti-allergic, anti-inflammatory, analgesic, antifungal, antimycotic, antibiotic, antiulcerative, anti...

Mona Hosseini-Sarvari, Sepideh Najafvand-Derikvandi

Nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(Trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. Factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  This nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. The prepared sulfated titania s...

In this study, the zinc chromium ferrite magnetic nanoparticles ZnCrFeO4 are synthesized via sol-gel method and characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The XRD analysis showed that ZnCrFeO4 has single-phase cubic structure. The synthesized ZnCrFeO4 has been used as an efficient catalyst for acetyl...

In this paper, 4,4ʹ-bipyridinium dichloride  supported SBA-15 (SBA@BiPy2+ 2Cl-) was used for the synthesis of dihydropyrimidinones. The synthesized catalyst was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Thermogravimetric analysis (TGA). This nanocomposite was shown to be an efficient heterogeneous ca...

1-substituted 1H-tetrazoles were efficiently synthesized under solvent-free conditions from the reaction of primary amines, triethylorthoformate, and sodium azide in the presence of Cu/C as a heterogeneous catalyst. Various amines including aromatic and heteroaromatic amines were used to afford the corresponding products in good to excellent yields. The characterization of corresponding product...

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