Active sites of vanadium-molybdenum-containing catalyst for allyl alcohol oxidation: ESR study in situ

1997 ◽  
pp. 275-284
Author(s):  
O.V. Krylov ◽  
Nguen Tien Tai ◽  
B.V. Rozentuller
Keyword(s):  
Allyl Alcohol ◽  
Active Sites ◽  
Alcohol Oxidation

scholarly journals Biomimetic Cu/Nitroxyl Catalyst Systems for Selective Alcohol Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 395 ◽  
Author(s):  
Lindie Marais ◽  
Andrew John Swarts
Keyword(s):  
Active Sites ◽  
Alcohol Oxidation ◽  
Galactose Oxidase ◽  
Co Catalyst ◽  
Co Catalysts ◽  
Mechanistic Pathway ◽  
Oxidation Of Alcohols ◽  
Catalyst Systems ◽  
Carbonyl Products

The oxidation of alcohols to the corresponding carbonyl products is an important organic transformation and the products are used in a variety of applications. The development of catalytic methods for selective alcohol oxidation have garnered significant attention in an attempt to find a more sustainable method without any limitations. Copper, in combination with 2,2,6,6-tetramethyl-1-piperidine N-oxyl (TEMPO) and supported by organic ligands, have emerged as the most effective catalysts for selective alcohol oxidation and these catalyst systems are frequently compared to galactose oxidase (GOase). The efficiency of GOase has led to extensive research to mimic the active sites of these enzymes, leading to a variety of Cu/TEMPO· catalyst systems being reported over the years. The mechanistic pathway by which Cu/TEMPO· catalyst systems operate has been investigated by several research groups, which led to partially contradicting mechanistic description. Due to the disadvantages and limitations of employing TEMPO· as co-catalyst, alternative nitroxyl radicals or in situ formed radicals, as co-catalysts, have been successfully evaluated in alcohol oxidation. Herein we discuss the development and mechanistic elucidation of Cu/TEMPO· catalyst systems as biomimetic alcohol oxidation catalysts.

scholarly journals Electrokinetic and in situ spectroscopic investigations of CO electrochemical reduction on copper

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Li ◽  
Xiaoxia Chang ◽  
Haochen Zhang ◽  
Arnav S. Malkani ◽  
Mu-jeng Cheng ◽  
...  
Keyword(s):  
Mass Transport ◽  
Active Sites ◽  
Gas Diffusion ◽  
Reduction Reaction ◽  
Adsorbed Hydrogen ◽  
Diffusion Type ◽  
Proton Coupled Electron Transfer ◽  
Alkaline Electrolytes ◽  
Reaction Orders

AbstractRigorous electrokinetic results are key to understanding the reaction mechanisms in the electrochemical CO reduction reaction (CORR), however, most reported results are compromised by the CO mass transport limitation. In this work, we determined mass transport-free CORR kinetics by employing a gas-diffusion type electrode and identified dependence of catalyst surface speciation on the electrolyte pH using in-situ surface enhanced vibrational spectroscopies. Based on the measured Tafel slopes and reaction orders, we demonstrate that the formation rates of C2+ products are most likely limited by the dimerization of CO adsorbate. CH4 production is limited by the CO hydrogenation step via a proton coupled electron transfer and a chemical hydrogenation step of CO by adsorbed hydrogen atom in weakly (7 < pH < 11) and strongly (pH > 11) alkaline electrolytes, respectively. Further, CH4 and C2+ products are likely formed on distinct types of active sites.

Diffuse Reflectance FT-IR Characterization of Active Sites under Reaction Conditions: The Production of Oxygenates in the CO/H2 Reaction

1994 ◽  
Vol 48 (10) ◽  
pp. 1208-1212 ◽  
Author(s):  
J. J. Benítez ◽  
I. Carrizosa ◽  
J. A. Odriozola
Keyword(s):  
Infrared Spectra ◽  
Active Sites ◽  
Diffuse Reflectance ◽  
Reaction Conditions ◽  
In Situ Drifts ◽  
Ft Ir

The reactivity of a Lu2O3-promoted Rh/Al2O3 catalyst in the CO/H2 reaction is reported. Methane, heavier hydrocarbons, methanol, and ethanol are obtained. In situ DRIFTS has been employed to record the infrared spectra under the actual reaction conditions. The structure of the observed COads DRIFTS bands has been resolved into its components. The production of oxygenates (methanol and ethanol) has been correlated with the results of the deconvolution calculation. Specific sites for the production of methanol and ethanol in the CO/H2 reaction over a Rh,Lu2O3/Al2O3 catalyst are proposed.

Construction of Hierarchical ZnIn2S4/C3N4 Heterojunction for Enhanced Photocatalytic Degradation of Tetracycline

2022 ◽  
Author(s):  
Feng Min ◽  
Zhengqing Wei ◽  
Zhen Yu ◽  
Yu-Ting Xiao ◽  
Shien Guo ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Organic Contaminants ◽  
Charge Separation ◽  
Active Sites ◽  
In Situ Growth ◽  
Efficient Charge

Both efficient charge separation and sufficiently exposed active sites are critical limiting for solar-driven organic contaminants degradation. Herein, we describe a hierarchical heterojunction photocatalyst fabricated by in situ growth of...

Electrochemically controlled in-situ conversion of CO2 to defective carbon nanotubes for enhanced H2O2 production

Nanoscale ◽  
2021 ◽  
Author(s):  
Ao Yu ◽  
Guoming Ma ◽  
Longtao Zhu ◽  
Yajing Hu ◽  
Ruiling Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Active Sites ◽  
Catalytic Reactions ◽  
H2o2 Production

Defects on carbon nanotubes (CNTs) can be used as active sites to promote the occurrence of catalytic reactions and improve the ability of catalysts. Although some progress has been made...

scholarly journals Visualization of Active Sites of Nanoporous Metal Catalyst by in-situ TEM Observation

Materia Japan ◽  
2016 ◽  
Vol 55 (12) ◽  
pp. 589-589
Author(s):  
Takeshi Fujita ◽  
Mingwei Chen ◽  
Tomoharu Tokunaga ◽  
Yuta Yamamoto ◽  
Shigeo Arai ◽  
...  
Keyword(s):  
Active Sites ◽  
Metal Catalyst ◽  
Nanoporous Metal

Photocatalytic reforming of glycerol for H2 evolution on Pt/TiO2: fundamental understanding the effect of co-catalyst Pt and the Pt deposition route

2015 ◽  
Vol 3 (5) ◽  
pp. 2271-2282 ◽  
Author(s):  
Xiaoliang Jiang ◽  
Xianliang Fu ◽  
Li Zhang ◽  
Sugang Meng ◽  
Shifu Chen
Keyword(s):  
Active Sites ◽  
H2 Evolution ◽  
Co Catalyst ◽  
Fundamental Understanding

The effects of deposited Pt and its deposition route on the photocatalytic reforming of glycerol for H2 evolution over Pt/TiO2 were investigated. Intimately loaded Pt(0) particles are the key active sites for the reaction, the formation of which was favored by an in situ photo-deposition route.

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