Novel Fe-Pd/SiO2 catalytic materials for degradation of chlorinated organic compounds in water

2014 ◽  
Vol 86 (7) ◽  
pp. 1141-1158 ◽  
Author(s):  
Leonid M. Kustov ◽  
Souhail R. Al-Abed ◽  
Jurate Virkutyte ◽  
Olga A. Kirichenko ◽  
Elena V. Shuvalova ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Nanoparticles ◽  
Ambient Conditions ◽  
Chlorinated Organic Compounds ◽  
Edge Structure ◽  
X Ray ◽  
Highly Dispersed ◽  
Chlorinated Organic ◽  
X Ray Absorption

AbstractNovel reactive materials for catalytic degradation of chlorinated organic compounds in water at ambient conditions have been prepared on the basis of silica-supported Pd-Fe nanoparticles. Nanoscale Fe-Pd particles were synthesized inside porous silica supports using (NH4)3[Fe(C2O4)3] and [Pd(NH3)4]Cl2 or Pd acetate as reaction precursors. According to temperature programmed reduction (TPR) studies, Pd introduction decreased the reduction temperature of the supported Fen+ species and nearly complete reduction with H2 was observed at 400 °C. The successful surface loading with Pd was confirmed by X-ray photoelectron spectroscopy (XPS) analysis. Characterization of the samples by X-ray diffraction (XRD) and X-ray absorption near-edge structure + extended X-ray absorption fine structure (XANES + EXAFS) verified the presence of highly dispersed Pd0, Pdx Fe1–x and Fe0 phases. Reduction of the supported precursors in hydrogen resulted in materials that were highly active in perchloroethene (PCE) degradation and 2-chlorobiphenyl (2-ClBP) dechlorination. It was found that highly dispersed amorphous Fe-Pd bimetallic nanoparticles on silica support showed superior catalytic activity against PCE dechlorination in comparison to the free-standing Fe-Pd nanoparticles. For the samples with the same Fe content, the conversion of chlorinated organics as well as the stability increased with the Pd loading, e.g., the most effective degradation of PCEs and 2-ClBP was achieved at a Pd loading of 2.3–3.2 wt. %.

Landscape of s-triazine molecule on Si(100) by a theoretical x-ray photoelectron spectroscopy and x-ray absorption near-edge structure spectra study

2018 ◽  
Vol 27 (11) ◽  
pp. 113101
Author(s):  
Jing Hu ◽  
Xiu-Neng Song ◽  
Sheng-Yu Wang ◽  
Juan Lin ◽  
Jun-Rong Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

X-ray absorption near the edge structure and X-ray photoelectron spectroscopy studies on pyrite prepared by thermally sulfurizing iron films

2009 ◽  
Vol 18 (7) ◽  
pp. 2734-2738 ◽  
Author(s):  
Zhang Hui ◽  
Liu Ying-Shu ◽  
Wang Bao-Yi ◽  
Wei Long ◽  
Kui Re-Xi ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Iron Films ◽  
Edge Structure ◽  
X Ray ◽  
Spectroscopy Studies ◽  
X Ray Absorption

scholarly journals The nature and effects of rhodium and antimony dopants on the electronic structure of TiO2: towards design of Z-scheme photocatalysts

2016 ◽  
Vol 4 (18) ◽  
pp. 6946-6954 ◽  
Author(s):  
E. N. K. Glover ◽  
S. G. Ellington ◽  
G. Sankar ◽  
R. G. Palgrave
Keyword(s):  
Fine Structure ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Antimony Doping ◽  
X Ray Absorption

The nature and effects of rhodium and antimony doping in TiO2 have been investigated using X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Extended X-ray Absorption Fine Structure (EXAFS), X-ray Absorption Near Edge Structure (XANES) and diffuse reflectance spectroscopy.

scholarly journals Neural network assisted analysis of bimetallic nanocatalysts using X-ray absorption near edge structure spectroscopy

2020 ◽  
Vol 22 (34) ◽  
pp. 18902-18910 ◽  
Author(s):  
Nicholas Marcella ◽  
Yang Liu ◽  
Janis Timoshenko ◽  
Erjia Guan ◽  
Mathilde Luneau ◽  
...  
Keyword(s):  
Neural Network ◽  
Local Structure ◽  
Bimetallic Nanoparticles ◽  
Edge Structure ◽  
X Ray ◽  
Coordination Numbers ◽  
Rich Information ◽  
Bimetallic Nanocatalysts ◽  
Assisted Analysis ◽  
X Ray Absorption

Trained neural networks are used to extract the first partial coordination numbers from XANES spectra. In bimetallic nanoparticles, the four local structure descriptors provide rich information on structural motifs.

Crystalline Phases and Electronic Structures in Superconducting Bi – Sr – Ca – Cu Oxides

1997 ◽  
Vol 12 (8) ◽  
pp. 2009-2013
Author(s):  
M. D. Giardina ◽  
R. Feduzi ◽  
D. Inzaghi ◽  
A. Manara ◽  
C. Giori ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Photoelectron Spectroscopy ◽  
Electronic Structures ◽  
Theoretical Interpretation ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Quantum Percolation ◽  
X Ray Absorption

Two classes of samples, designated A and B, of layered Bi–Sr–Ca–Cu oxides having the same nominal composition 4 : 3 : 3 : 4, but different thermal histories, were investigated by using field modulated microwave absorption (ESR), powder x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and x-ray absorption near the edge structure (XANES). Previous electrical resistivity measurements showed that the B samples presented only two superconducting phases with midpoints of the transition temperatures at ∼80 K and ∼105 K. The microwave absorption technique indicated instead the presence of islands which became superconducting at the above-mentioned temperatures also in the A samples. The crystalline and electronic structures of the two types of samples are illustrated and discussed. A plausible theoretical interpretation of the experimental results, based on a quantum percolation model with Coulomb interaction, is also given.

Effect of gamma irradiation on X-ray absorption and photoelectron spectroscopy of Nd-doped phosphate glass

2016 ◽  
Vol 23 (6) ◽  
pp. 1424-1432 ◽  
Author(s):  
V. N. Rai ◽  
Parasmani Rajput ◽  
S. N. Jha ◽  
D. Bhattacharyya ◽  
B. N. Raja Shekhar ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Photoelectron Spectroscopy ◽  
Glass Matrix ◽  
Structural Changes ◽  
Phosphate Glasses ◽  
White Line ◽  
Edge Structure ◽  
Xps Spectra ◽  
X Ray ◽  
X Ray Absorption

X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS) of Nd-doped phosphate glasses have been studied before and after gamma irradiation. The intensity and the location of the white line peak of theL3-edge XANES of Nd are found to be dependent on the ratio O/Nd in the glass matrix. Gamma irradiation changes the elemental concentration of atoms in the glass matrix, which affects the peak intensity of the white line due to changes in the covalence of the chemical bonds with Nd atoms in the glass (structural changes). Sharpening of the Nd 3d5/2peak profile in XPS spectra indicates a deficiency of oxygen in the glasses after gamma irradiation, which is supported by energy-dispersive X-ray spectroscopy measurements. The ratio of non-bridging oxygen to total oxygen in the glass after gamma radiation has been found to be correlated to the concentration of defects in the glass samples, which are responsible for its radiation resistance as well as for its coloration.

Investigation of damaged interior walls using synchrotron-based XPS and XANES

2015 ◽  
Vol 22 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Yingyot Poo-arporn ◽  
Surachai Thachepan ◽  
Rungtiva Palangsuntikul
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sulfate Attack ◽  
Field Exposure ◽  
Edge Structure ◽  
X Ray ◽  
Black Layer ◽  
Interior Walls ◽  
X Ray Absorption ◽  
Chemical Integrity ◽  
Internal Sulfate Attack

Evidence of internal sulfate attack in field exposure was demonstrated by the damaged interior wall of a three-year-old house situated in Nakhon Ratchasima Province, Thailand. Partial distension of the mortar was clearly observed together with an expansion of a black substance. Removal of the black substance revealed a dense black layer. This layer was only found in the vicinity of the damaged area, suggesting that this black material is possibly involved in the wall cracking. By employing synchrotron-based X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge structure (XANES) techniques, the unknown sample was chemically identified. The S 2pand O 1sXPS results mutually indicated the existence of sulfate species in the materials collected from the damaged area. The XANES results indicated the presence of ferrous (II) sulfate, confirming sulfate-induced expansion and cracking. The sulfate attack in the present case appeared to physically affect the structure whereas the chemical integrity at the molecular level of the calcium silicate hydrate phase was retained since there was a lack of spectroscopic evidence for calcium sulfate. It was speculated that internal sulfate probably originated from the contaminated aggregates used during the construction. The current findings would be beneficial for understanding the sulfate-attack mechanism as well as for future prevention against sulfate attack during construction.

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