C2 Alcohol Oxidation Boosted by Trimetallic PtPbBi Hexagonal Nanoplates

2020 ◽  
Vol 12 (47) ◽  
pp. 52731-52740
Author(s):  
Zhiqiang Zhu ◽  
Feng Liu ◽  
Jinchen Fan ◽  
Qiaoxia Li ◽  
Yulin Min ◽  
...  
1982 ◽  
Vol 47 (8) ◽  
pp. 2061-2068 ◽  
Author(s):  
Jan Sýkora ◽  
Mária Jakubcová ◽  
Zuzana Cvengrošová

In the photolysis of copper(II)-chloride-alcohol-acetonitrile systems (cCu = 1 mmol l-1, copper(II)-to-chloride molar ratio 1 : 2 to 1 : 8, 10% (v/v) alcohol), Cu(II) is reduced to Cu(I), and methanol, ethanol, 1-propanol, or 1-butanol is oxidized to the corresponding aldehyde, 2-propanol to acetone. In the case of 1-propanol and 1-butanol, chlorinated aldehydes are formed in addition too. The measured quantum yields of the photoreduction of Cu(II) to Cu(I) lay in the range of ΦCu(I) = 4.5 to 40 mmol einstein-1, the absolute quantum yields of the alcohol oxidation products were 2.3 to 47 mmol einstein-1. The photoactive components are chlorocupric complexes [CuClx](2-x)+ (x = 1-4). The presence of complexes with a higher number of chloroligands in the coordination sphere (x = 3, 4) brings about a decrease in the Cu(II) photoreduction rate. The decrease in the photoreduction rate observed in the presence of dioxygen is explained in terms of re-oxidation of copper(I) by the latter, resulting in an increase in the concentration of the photochemically active cupric complexes. The catalytic aspects of the systems in question are discussed with respect to this effect.


2021 ◽  
Author(s):  
Kadriye Özlem Hamaloğlu ◽  
Rukiye Babacan Tosun ◽  
Serap Ulu ◽  
Hakan Kayi ◽  
Cengiz Kavaklı ◽  
...  

A synergistic catalyst in the form of monodisperse-porous CeO2 microspheres supported Pd nanoparticles (Pd NPs) was synthesized. CeO2 microspheres 4 μm in size were obtained by a newly developed “sol-gel...


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Xiaoyun Qin ◽  
Dongdong Shi ◽  
Bowen Guo ◽  
Cuicui Fu ◽  
Jin Zhang ◽  
...  

Abstract One-dimensional (1D) nanomaterials with specific architectures have received increasing attention for both scientific and technological interests for their applications in catalysis, sensing, and energy conversion, etc. However, the development of an operable and simple method for the fabrication of 1D nanostructures remains a challenge. In this work, we developed an “anion-regulated morphology” strategy, in which anions could regulate the dimensionally-restricted anisotropic growth of ZnO nanomaterials by adjusting the surface energy of different growth facets. ZnO 1D necklace-like nanostructures (NNS) could be prepared through a hydrothermal treatment of zinc acetate and urea mixture together with a subsequent calcination procedure at 400 °C. While replacing the acetate ions to nitrate, sulfate, and chlorion ions produced ZnO nanoflowers, nanosheets and hexagonal nanoplates, respectively. Density functional theory calculations were carried out to explain the mechanism behind the anions-regulating anisotropic crystal growth. The specified ZnO 1D NNS offered improved electron transport while the grain surface could supply enlarged specific surface area, thus providing advanced photocatalytic ability in the following photodegradation of methyl orange (MO). Among the four photocatalysts with different morphologies, ZnO 1D NNS, possessing the highest catalytic activity, degraded 57.29% MO in the photocatalytic reaction, which was 2 times, 10 times and 17 times higher than nanoflowers, nanosheets and hexagonal nanoplates, respectively. Our work provides new ideas for the construction and application of ZnO 1D nanomaterials.


2016 ◽  
Vol 28 ◽  
pp. 178-184 ◽  
Author(s):  
Seunghwan Seok ◽  
Muhammad Asif Hussain ◽  
Kyun Joo Park ◽  
Jung Won Kim ◽  
Do Hyun Kim

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Ivan Bassanini ◽  
Erica Elisa Ferrandi ◽  
Sergio Riva ◽  
Daniela Monti

Laccases are multicopper oxidases, which have been widely investigated in recent decades thanks to their ability to oxidize organic substrates to the corresponding radicals while producing water at the expense of molecular oxygen. Besides their successful (bio)technological applications, for example, in textile, petrochemical, and detoxifications/bioremediations industrial processes, their synthetic potentialities for the mild and green preparation or selective modification of fine chemicals are of outstanding value in biocatalyzed organic synthesis. Accordingly, this review is focused on reporting and rationalizing some of the most recent and interesting synthetic exploitations of laccases. Applications of the so-called laccase-mediator system (LMS) for alcohol oxidation are discussed with a focus on carbohydrate chemistry and natural products modification as well as on bio- and chemo-integrated processes. The laccase-catalyzed Csp2-H bonds activation via monoelectronic oxidation is also discussed by reporting examples of enzymatic C-C and C-O radical homo- and hetero-couplings, as well as of aromatic nucleophilic substitutions of hydroquinones or quinoids. Finally, the laccase-initiated domino/cascade synthesis of valuable aromatic (hetero)cycles, elegant strategies widely documented in the literature across more than three decades, is also presented.


Sign in / Sign up

Export Citation Format

Share Document