Silica-Copper Molybdate Catalysts Prepared by Sol-Gel and Impregnation Methods: Reactivity and Spectroscopic Studies

1998 ◽  
Vol 549 ◽  
Author(s):  
C. Canevali ◽  
F. Morazzoni ◽  
R. Scotti ◽  
D. Cauzzi ◽  
G. Predieri ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Catalytic Activity ◽  
Flow Reactor ◽  
Sol Gel ◽  
Structural Features ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Electron Paramagnetic

AbstractSilica-copper molybdates prepared by sol-gel and impregnation methods were tested as catalysts in the oxidation of propene at 400°C, both in a pulse and in a flow reactor. Their catalytic activity is connected to their structural features, as revealed by electron paramagnetic resonance (EPR) and X-ray diffraction (XRD) characterization.

scholarly journals Sol-Gel Synthesis and Characterization of Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
S. Ramesh
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Paramagnetic Resonance ◽  
Optical Absorption ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Electron Paramagnetic ◽  
Scanning Electron

The nanoparticles have been synthesized by sol-gel technique. X-ray diffraction, scanning electron microscopy, optical absorption spectroscopy, and electron paramagnetic resonance spectroscopy were used to characterize the sample. The X-ray diffraction results indicate the formation of nanocrystalline materials in tetragonal lattice with P42/nnm space group. The identical distribution of elements were confirmed by scanning electron microscopy with energy dispersive X-ray spectrometry and X-ray mapping. Electron paramagnetic resonance lineshapes of the samples are obtained at various (13 K, 77 K, and 300 K) temperatures. The isotropic lineshapes of the sample B1 are attributed to dipole-dipole interaction of Ti3+ ions. The incorporation of Al3+ ions into the sample B2–B5 the isotropic nature of the lineshapes are collapsed due to the distraction in crystal field. Optical absorption spectra results reveal the presence of Ag-TiO2 nanoparticles.

scholarly journals Influence of the Substituted Ethylenediamine Ligand on the Structure and Properties of [Cu(diamine)2Zn(NCS)4]∙Solv. Compounds

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 637
Author(s):  
Natalia Tereba ◽  
Tadeusz M. Muzioł ◽  
Robert Podgajny ◽  
Grzegorz Wrzeszcz
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Magnetic Interaction ◽  
Structural Features ◽  
Molecular Formula ◽  
Structure And Properties ◽  
Magnetic Studies ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Ethylenediamine Ligand ◽  
Electron Paramagnetic

In this paper, three new heterometallic compounds were described and compared with the molecular formula [Cu(pn)2Zn(NCS)4] (1), [Cu(N,N-Me2-en)2Zn(NCS)4] (2), [Cu(N-Me-en)2Zn(NCS)4]∙½H2O (3) where pn = 1,2−diaminopropane, N,N-Me2-en = N,N‒dimethylethylenediamine and N-Me-en = N-methylethylenediamine, respectively. The compounds mentioned above were characterized by elemental analysis, infrared (IR), electronic, electron paramagnetic resonance (EPR) spectra, and magnetic studies. Crystal structures for 1 and 2 were determined by X-ray analysis. Copper(II) in these complexes adopts 4 + 2 coordination with two elongated (in 2 very long and considered as semi-coordination) Cu-S bonds. The Cu-N and Cu-S bond lengths depend on substituent position affecting steric hindrance and hence a topology of the chain. Both chains form different zigzag patterns characterized by one or two Cu-Zn distance values. Weak magnetic interaction is observed, ferromagnetic in the case of 1 and antiferromagnetic in the case of 2, due to diversity of the above structural features.

Probing the Structure and Visible Light Photocatalytic Mechanism of LaVO4/TiO2 Composite Using XRD, BET, and EPR

2012 ◽  
Vol 217-219 ◽  
pp. 737-740
Author(s):  
Han Jie Huang
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Visible Light ◽  
Gas Phase ◽  
Spin Trapping ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Photocatalytic Mechanism ◽  
Electron Paramagnetic ◽  
Visible Light Photocatalytic

In this work, a visible light-induced LaVO4/TiO2 composite has been characterized by powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and spin-trapping electron paramagnetic resonance (EPR) to reveal the structure and visible light photocatalytic mechanism for the decompostion of benzene in gas-phase. Based on the experimental results, a visible light-induced photochemical processes on LaVO4/TiO2 are proposed and elucidated.

scholarly journals X-Ray Diffraction, Electron Paramagnetic Resonance and Optical Absorption Study of Bauxite

2014 ◽  
Vol 02 (02) ◽  
pp. 114-120
Author(s):  
Tanguturi Ravindra Reddy ◽  
Krishnan Thyagarajan ◽  
Ovidio Almanza Montero ◽  
Sanapa Reddy Lakshmi Reddy ◽  
Tamio Endo
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Optical Absorption ◽  
Absorption Study ◽  
X Ray Diffraction ◽  
Optical Absorption Study ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Diffraction Electron ◽  
Electron Paramagnetic

Persistent P-Stabilized Boryl Radicals with Bulky Substituents at Boron

Synthesis ◽  
2018 ◽  
Vol 50 (18) ◽  
pp. 3671-3678
Author(s):  
Didier Bourissou ◽  
Amos Rosenthal ◽  
Sonia Mallet-Ladeira ◽  
Ghenwa Bouhadir
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Room Temperature ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Radical Reactivity ◽  
Different Types ◽  
Electron Paramagnetic

Two new P-stabilized boryl radicals [Ph2P(naph)BAr] (Ar = Tip and Ter) have been prepared and characterized by electron paramagnetic resonance spectroscopy. These radicals are persistent for several days in solution at room temperature. The high steric congestion at boron does not prevent radical reactivity. Two different types of dimerization equilibrium have been observed. The structures of the dimers have been unambiguously established by X-ray diffraction crystallography.

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