نتایج جستجو برای: cobalt catalyst

تعداد نتایج: 72536  

2005
Y. Kemmochi M. Hu Y. Murakami M. Ogura S. Maruyama T. Okubo

Vertically oriented single-walled carbon nanotubes (SWNTs) attract considerable attention, because it is expected as an ideal field emitter that can realize lower threshold voltage and higher electric current than microtips of Si or metals. In this study, we aim that SWNTs are vertically oriented using mesoporous silica film as a guide of the growth for SWNTs. For the orientation, the catalyst ...

2003
Enrique Iglesia

Catalyst productivity and selectivity to C5+ hydrocarbons are critical design criteria in the choice of Fischer-Tropsch synthesis (FTS) catalysts and reactors. Cobalt-based catalysts appear to provide the best compromise between performance and cost for the synthesis of hydrocarbons from CO/H2 mixtures. Optimum catalysts with high cobalt concentration and site density can be prepared by control...

2016
Jamie M. Neely Máté J. Bezdek Paul J. Chirik

Among the fundamental transformations that comprise a catalytic cycle for cross coupling, transmetalation from the nucleophile to the metal catalyst is perhaps the least understood. Optimizing this elementary step has enabled the first example of a cobalt-catalyzed Suzuki-Miyaura cross coupling between aryl triflate electrophiles and heteroaryl boron nucleophiles. Key to this discovery was the ...

Journal: :Nanoscale 2015
Camélia Matei Ghimbeu Mihai Sopronyi Felix Sima Luc Delmotte Cyril Vaulot Claudia Zlotea Valérie Paul-Boncour Jean-Marc Le Meins

A novel one-pot laser-assisted approach is reported herein for the synthesis of ordered carbons with embedded cobalt nanoparticles. The process is based on a UV pulsed laser exposure of an ethanolic solution consisting of green carbon precursors, a structure directing agent and a cobalt salt. Very short irradiation times (5 to 30 min) are only required to polymerize and cross-link carbon precur...

An improved rapid one-pot and green synthesis of substituted pyranopyranes by condensing Kojic acid, malononitrile, and different aldehydes and using a catalytic amount of cobalt nanoparticles as green and reusable catalyst is reported for the first time. The reaction proceeds in aqueous media at ambient temperature. Furthermore, the structural and morphological study of the cobalt nanoparticle...

2016
Ana Raquel de la Osa Amaya Romero Fernando Dorado José Luis Valverde Paula Sánchez

β-SiC-supported cobalt catalysts have been prepared from nitrate, acetate, chloride and citrate salts to study the dependence of Fischer–Tropsch synthesis (FTS) on the type of precursor. Com/SiC catalysts were synthetized by vacuum-assisted impregnation while N2 adsorption/desorption, XRD, TEM, TPR, O2 pulses and acid/base titrations were used as characterization techniques. FTS catalytic perfo...

Journal: :iranian journal of catalysis 0
mohammad ali ghasemzadeh department of chemistry, qom branch, islamic azad university, qom, p.o. box 364/37185. i.r. iran. zahra elyasi department of chemistry, qom branch, islamic azad university, qom, p.o. box 364/37185. i.r. iran.

this study introduces a green and efficient method for preparation of biologically-active substituted 4h-pyrans using the one-pot three-component reaction of aromatic aldehydes, dimedone and malononitrile in the presence of cobalt oxide nanoparticles. co3o4 nanoparticles were used as an efficient catalyst for the synthesis of polyhydroquinoline derivatives by the reaction of aromatic aldehydes,...

Journal: : 2023

The E. coli inactivation using hydrogen peroxide (H2O2) and cobalt ferrite granulated catalyst was investigated in a fixed-bed flow reactor. CoFe2O4 synthesized by the co-precipitation method, granulated, annealed at 1150°C. X-ray diffraction analysis used to identify crystal structure of catalyst. demonstrates good catalytic activity for bacteria presence H2O2. An increase concentration increa...

Journal: :Catalysts 2022

In this work, a metal cobalt catalyst was synthesized, and its activity in the hydrogen production process tested. The substrates were water ethanol. Activity tests conducted at temperature range of 350–600 °C, to ethanol molar ratio 3 5, feed flow 0.4 1.2 mol/h. had specific surface area 1.75 m2/g. most active temperatures 500–600 °C. Under favorable conditions, conversion 97%, efficiency 4.9 ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2017
Cyrille Costentin Daniel G Nocera

Principles for designing self-healing water-splitting catalysts are presented together with a formal kinetics model to account for the key chemical steps needed for self-healing. Self-healing may be realized if the catalysts are able to self-assemble at applied potentials less than that needed for catalyst turnover. Solution pH provides a convenient handle for controlling the potential of these...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید