نتایج جستجو برای: heterogeneous and homogeneous catalyst

تعداد نتایج: 16861159  

SnCl4/nano-sawdust was prepared as a carbohydrate-based catalyst containing of tin bearing cellulose units. The catalyst was characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). The catalyst was applied successfully as a readily available, inexpensive, biodeg...

2010
Nabeel S. Abo-Ghander Filip Logist John R. Grace Jan F. Van Impe Jim Lim

The coupling of reactions in catalytic membrane reactors provides novel reactor configurations that allow shifting the thermodynamic equilibrium and yields of thermodynamically limited reactions and enhancing significantly the rate of production. An interesting pair to couple is the dehydrogenation of ethylbenzene to styrene and the hydrogenation of nitrobenzene to aniline. Hydrogen produced in...

S. Senthilkumar, V. Ramakrishnan,

Background: The heterogeneous composition of the human body presents numerous tissue types and cavities with widely differing radiologic properties. The aim of the present work was to develop a low cost homogeneous and heterogeneous phantom and the absorbed dose were measured by ionization chamber for different radiotherapy treatment techniques and compared with treatment planning syst...

2015
Fan Shi Aaron M. Coffey Kevin W. Waddell Eduard Y. Chekmenev Boyd M. Goodson

Two types of nanoscale catalysts were created to explore NMR signal enhancement via reversible exchange (SABRE) at the interface between heterogeneous and homogeneous conditions. Nanoparticle and polymer comb variants were synthesized by covalently tethering Ir-based organometallic catalysts to support materials comprised of TiO2/PMAA (poly methacrylic acid) and PVP (polyvinyl pyridine), respec...

2016
Liangbing Wang Wenbo Zhang Shenpeng Wang Zehua Gao Zhiheng Luo Xu Wang Rui Zeng Aowen Li Hongliang Li Menglin Wang Xusheng Zheng Junfa Zhu Wenhua Zhang Chao Ma Rui Si Jie Zeng

Rh-based heterogeneous catalysts generally have limited selectivity relative to their homogeneous counterparts in hydroformylation reactions despite of the convenience of catalyst separation in heterogeneous catalysis. Here, we develop CoO-supported Rh single-atom catalysts (Rh/CoO) with remarkable activity and selectivity towards propene hydroformylation. By increasing Rh mass loading, isolate...

Journal: :Nature communications 2014
Matthew R Decan Stefania Impellizzeri M Luisa Marin Juan C Scaiano

Colloidal or heterogeneous nanocatalysts can improve the range and diversity of Cu(I)-catalysed click reactions and facilitate catalyst separation and reuse. Catalysis by metal nanoparticles raises the question as to whether heterogeneous catalysts may cause homogeneous catalysis through metal ion leaching, since the catalytic process could be mediated by the particle, or by metal ions released...

2017
Hoyoung D. Park Mircea Dincă Yuriy Román-Leshkov

Despite the commercial desirability of epoxide carbonylation to β-lactones, the reliance of this process on homogeneous catalysts makes its industrial application challenging. Here we report the preparation and use of a Co(CO)4--incorporated Cr-MIL-101 (Co(CO)4⊂Cr-MIL-101, Cr-MIL-101 = Cr3O(BDC)3F, H2BDC = 1,4-benzenedicarboxylic acid) heterogeneous catalyst for the ring-expansion carbonylation...

2011
B. Narendra Kumar

The present work is focused on the homogeneous and heterogeneous photo-catalytic degradation of Hacid, a non-biodegradable dye intermediate from dye manufacturing industries, using Advanced Oxidation Processes (AOPs) such as UV, UV/H2O2, UV/H2O2/Fe 2+ (photo-Fenton process), UV/TiO2 and UV/H2O2/TiO2. Degradation experiments were carried out to optimize the amount of catalyst, effect of Hacid co...

Journal: :iranian journal of catalysis 2012
javad safari zohre zarnegar

to be fairly general and catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction. fe3o4 nanoparticles were prepared by chemical coprecipitation method and was found to be a mild and effective catalyst for the efficient, one-pot, three-component synthesis of 2,4,5-trisubstituted imidazoles at room temperature under ultrasound irra...

Journal: :iranian journal of catalysis 2014
leila youseftabar-miri fatemeh akbari farshid ghraghsahar

eggshell was found to be a versatile heterogeneous catalyst for the synthesis of pyrano[3,2-c]quinoline derivatives in good yields. this protocol has the advantages of environmental friendliness, short reaction time, low cost and convenient operation.

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