Styrene oxidation catalyzed by copper(II) C-scorpionates in homogenous medium and immobilized on sucrose derived hydrochars

2020 ◽  
Vol 357 ◽  
pp. 56-63 ◽  
Author(s):  
Tiago A.G. Duarte ◽  
Ana P. Carvalho ◽  
Luísa M.D.R.S. Martins
Keyword(s):  
Styrene Oxidation ◽  
Homogenous Medium

scholarly journals Controlling Product Selectivity with Nanoparticle Composition in Tandem Chemo-Biocatalytic Styrene Oxidation

2021 ◽  
Author(s):  
Derik Wilbers ◽  
Joseph Brehm ◽  
Richard Lewis ◽  
Jacqueline Van Marwijk ◽  
Thomas Davies ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Product Selectivity ◽  
Styrene Oxidation ◽  
One Pot ◽  
Potential Approach ◽  
Reaction Cascades

The combination of heterogeneous catalysis and biocatalysis into one-pot reaction cascades is a potential approach to integrate enzymatic transformations into existing chemical infrastructure. Peroxygenases, which can achieve clean C-H activation,...

scholarly journals Selective Styrene Oxidation to Benzaldehyde over Recently Developed Heterogeneous Catalysts

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1680
Author(s):  
Marta A. Andrade ◽  
Luísa M. D. R. S. Martins
Keyword(s):  
Heterogeneous Catalysts ◽  
Carbon Materials ◽  
Oxygen Species ◽  
Styrene Oxidation ◽  
Reaction Conditions ◽  
Reactive Metal ◽  
Catalytic Systems ◽  
Tert Butyl Hydroperoxide ◽  
Metal Organic ◽  
Important Intermediate

The selective oxidation of styrene under heterogeneous catalyzed conditions delivers environmentally friendly paths for the production of benzaldehyde, an important intermediate for the synthesis of several products. The present review explores heterogeneous catalysts for styrene oxidation using a variety of metal catalysts over the last decade. The use of several classes of supports is discussed, including metal–organic frameworks, zeolites, carbon materials and silicas, among others. The studied catalytic systems propose as most used oxidants tert-butyl hydroperoxide, and hydrogen peroxide and mild reaction conditions. The reaction mechanism proceeds through the generation of an intermediate reactive metal–oxygen species by catalyst-oxidant interactions. Overall, most of the studies highlight the synergetic effects among the metal and support for the activity and selectivity enhancement.

scholarly journals Sustainable M-MOF-74 (M = Cu, Co, Zn) prepared in methanol as heterogeneous catalysts in the synthesis of benzaldehyde from styrene oxidation

2021 ◽  
pp. 122151
Author(s):  
J. Gabriel Flores ◽  
Manuel Díaz-García ◽  
Ilich A. Ibarra ◽  
Julia Aguilar-Pliego ◽  
Manuel Sánchez-Sánchez
Keyword(s):  
Heterogeneous Catalysts ◽  
Styrene Oxidation

Improvement of catalytic activity in styrene oxidation of carbon-coated titania by formation of porous carbon layer

2012 ◽  
Vol 209 ◽  
pp. 486-493 ◽  
Author(s):  
Surya Lubis ◽  
Leny Yuliati ◽  
Siew Ling Lee ◽  
Imam Sumpono ◽  
Hadi Nur
Keyword(s):  
Catalytic Activity ◽  
Porous Carbon ◽  
Carbon Layer ◽  
Styrene Oxidation ◽  
Carbon Coated

scholarly journals Dynamics of sheared droplets filled with non-Brownian particles

2020 ◽  
Vol 59 (12) ◽  
pp. 935-949
Author(s):  
Helene Van Ammel ◽  
Paula Moldenaers ◽  
Ruth Cardinaels
Keyword(s):  
Bulk Viscosity ◽  
Particle Concentration ◽  
Viscosity Ratio ◽  
Viscous Medium ◽  
Particle Sizes ◽  
Droplet Dynamics ◽  
Brownian Particles ◽  
Homogenous Medium ◽  
Single Droplets ◽  
Good Agreement

AbstractThe dynamics of single droplets containing non-Brownian particles are studied. The particle over droplet size ratio (r/R) is changed by using different particle sizes (r/R = 0.02–0.4). Additionally, the effect of particle concentration (5–20 vol%) is investigated. The dynamics of droplets with r/R = 0.02 show good agreement with the corresponding particle-free reference system which has a comparable viscosity ratio. Hence, this droplet phase can be considered as a homogenous medium characterized by its bulk viscosity which is governed by the particle concentration. However, droplets with r/R ≥ 0.1 show a more suppressed deformation and slower transient dynamics and, therefore, behave as a slightly more viscous medium than expected based on their bulk viscosity. These effects become more pronounced at higher particle concentrations and higher r/R. Moreover, local particle effects like asymmetric droplet shapes, oscillating droplet shapes, and tip streaming start to influence the droplet dynamics at particle concentrations around 15 vol%.

scholarly journals Zn(II)-to-Cu(II) Transmetalation in an Amide Functionalized Complex and Catalytic Applications in Styrene Oxidation and Nitroaldol Coupling

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2644 ◽  
Author(s):  
Anup Paul ◽  
Luísa M. D. R. S. Martins ◽  
Anirban Karmakar ◽  
Maxim L. Kuznetsov ◽  
M. Fátima C. Guedes da Silva ◽  
...  
Keyword(s):  
Density Functional ◽  
Coupling Reaction ◽  
X Ray Diffraction ◽  
Styrene Oxidation ◽  
Aqueous Hydrogen Peroxide ◽  
Functional Theory ◽  
Catalytic Activities ◽  
Eds Analysis ◽  
Carboxylate Groups ◽  
Thermodynamic Feasibility

The mononuclear zinc(II) complex cis-[ZnL2(H2O)2] (1; L = 4-(pyridin-3-ylcarbamoyl)benzoate) was synthesized and characterized. By soaking crystals of 1 in a mixture of DMF-H2O solution containing a slight excess of Cu(NO3)2 × 3H2O a transmetalation reaction occurred affording the related copper(II) complex trans-[CuL2(H2O)2] (2). The structures of the compounds were authenticated by single crystal X-ray diffraction revealing, apart from a change in the isomerism, an alteration in the relative orientation of the chelating carboxylate groups and of the pyridine moieties. H-bond interactions stabilize both geometries and expand them into two-dimensional (2D) networks. The transmetalation was confirmed by SEM–EDS analysis. Moreover, the thermodynamic feasibility of the transmetalation is demonstrated by density-functional theory (DFT) studies. The catalytic activities of 1 and 2 for the oxidation of styrene and for the nitroaldol (Henry) C-C coupling reaction were investigated. The copper(II) compound 2 acts as heterogeneous catalyst for the microwave-assisted oxidation of styrene with aqueous hydrogen peroxide, yielding selectively (>99%) benzaldehyde up to 66% of conversion and with a turnover frequency (TOF) of 132 h−1. The zinc(II) complex 1 is the most active catalyst (up to 87% yield) towards the nitroaldol (Henry) coupling reaction between benzaldehyde and nitro-methane or -ethane to afford the corresponding β-nitro alcohols. The reaction of benzaldehyde with nitroethane in the presence of 1 produced 2-nitro-1-phenylpropanol in the syn and the anti diastereoisomeric forms, with a considerable higher selectivity towards the former (66:34).

scholarly journals Homogenization of a Conductive and Radiative Heat Transfer Problem, Simulation With CAST3M

2005 ◽  
Author(s):  
K. El Ganaoui ◽  
G. Allaire
Keyword(s):  
Boundary Condition ◽  
Radiative Heat ◽  
Transfer Problem ◽  
Computer Code ◽  
Homogenization Theory ◽  
Linear Boundary ◽  
Mathematical Study ◽  
Linear Boundary Condition ◽  
The Core ◽  
Homogenous Medium

We are interested in conductive and radiative transfer of energy in the core of gas cooled reactors. Two scales characterize the problem: macroscopic and microscopic. We want to consider the domain like an equivalent homogenous medium. So we use homogenization theory to compute the effective macroscopic properties which take into account the microscopic structure. We first present a full mathematical study of a simpler conduction problem with non linear boundary condition and its simulation with the CEA’s (French Atomic Energy Commissariat) computer code CAST3M. Then we present the homogenization of the real physical problem (including radiative boundary condition).

Sign in / Sign up

Export Citation Format

Share Document