نتایج جستجو برای: cu catalysts

تعداد نتایج: 92695  

2017
Rupali Mishra Bhushan Patil Ferdi Karadaş Eda Yılmaz

Non–noble metal catalysts have recently emerged as promising alternatives to the expensive platinum catalysts for the oxygen reduction reaction (ORR). In this study, a new domain of materials, copper based coordination polymers, has been investigated as promising catalysts for ORR. The study was inspired by copper incorporating biomolecules, which efficiently catalyse the oxygen reduction react...

Journal: :Angewandte Chemie 2014
Matthias B Fichtl Julia Schumann Igor Kasatkin Nikolas Jacobsen Malte Behrens Robert Schlögl Martin Muhler Olaf Hinrichsen

Different surface sites of solid catalysts are usually quantified by dedicated chemisorption techniques from the adsorption capacity of probe molecules, assuming they specifically react with unique sites. In case of methanol synthesis catalysts, the Cu surface area is one of the crucial parameters in catalyst design and was for over 25 years commonly determined using diluted N2O. To disentangle...

Series of Copper Ruthenium (Cu-Ru) bimetallic catalysts supported on γ-Al2O3 with different metal loading are prepared and investigated for catalytic wet air oxidation of ammonia to nitrogen. The ammonia decomposition activity was studied at three different temperatures i.e. 150oC, 200oC, and 230 oC and it is found that catalytic activity increases with the increase in temperature along with th...

The CO preferential oxidation (PrOx) is one of the critical steps in hydrogen production and purification for Polymer Electrolyte Membrane Fuel Cell (PEMFC). This reaction was investigated in the presence of excess hydrogen over Cu/CeO2, Pt/CeO2 and Cu-Pt/CeO2 catalysts. The ceria supports was prepared via precipitation method and Cu-Pt/CeO2 catalyst was synthesized by sequential impregnation o...

2016
Le Anh Tuan Keiichi N. Ishihara

The performance of Ni-Cu/Al2O3 catalysts for steam reforming (SR) of gasoline to produce a hydrogen-rich gas mixture applied in a spark ignition (SI) engine was investigated at relatively low temperature. The structural and morphological features and catalysis activity were observed by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and temperature programmed reduction (TPR). Th...

1999
George Meitzner Enrique Iglesia

X-ray absorption spectroscopic studies from several different groups provide a consistent structural picture of methanol synthesis catalysts. Copper metal is the principal Cu species detected in all in-situ XAS studies. A small amount of Cu(II) persisted in many samples reduced below 600 K, but it appears to be catalytically irrelevant. Cu(I) was not detected in any of the in-situ XAS studies. ...

2013
José M. Fraile José A. Mayoral Nicoletta Ravasio Marta Roldán Laura Sordelli Federica Zaccheria

Copper catalysts supported on silica or silica-alumina are used to promote the insertion of carbenes, coming from methyl phenyldiazoacetate and ethyl diazoacetate, into one C-H bond of THF, constituting the first example of this reaction promoted by a purely inorganic catalyst. Cu/SiO2-Al2O3 leads to better results, regarding yield and catalyst recovery, than with Cu/SiO2. With the former catal...

J. Farzanfar R. Rezvani

The present study examined the effect of three methods of preparation on the properties and catalytic performance of Cu-Mn/SiO2 catalysts for the water gas shift reaction (WGSR). Impregnation and coprecipitation and the new approach of thermal decomposition of [Cu(H2O)6][Mn(dipic)2].2H2O/SiO2 inorganic precursor complex were used for the synthesis of the silica-supported copper-manganese mixed ...

2017
Martina Tireli Silvija Maračić Stipe Lukin Marina Juribašić Kulcsár Dijana Žilić Mario Cetina Ivan Halasz Silvana Raić-Malić Krunoslav Užarević

Copper-catalyzed mechanochemical click reactions using Cu(II), Cu(I) and Cu(0) catalysts have been successfully implemented to provide novel 6-phenyl-2-(trifluoromethyl)quinolines with a phenyl-1,2,3-triazole moiety at O-4 of the quinoline core. Milling procedures proved to be significantly more efficient than the corresponding solution reactions, with up to a 15-fold gain in yield. Efficiency ...

Journal: :The journal of physical chemistry. B 2006
Xianqin Wang José A Rodriguez Jonathan C Hanson Daniel Gamarra Arturo Martínez-Arias Marcos Fernández-García

New information about the active sites for the water gas shift (WGS) reaction over Cu-CeO2 systems was obtained using in-situ, time-resolved X-ray diffraction (TR-XRD), X-ray absorption spectroscopy (TR-XAS, Cu K and Ce L3 edges), and infrared spectroscopy (DRIFTS). Cu-CeO2 nanoparticles prepared by a novel reversed microemulsion method (doped Ce1-xCuxO2 sample) and an impregnation method (impr...

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