scholarly journals Chemical Degradation of the La0.6Sr0.4Co0.2Fe0.8O3−δ/Ce0.8Sm0.2O2−δ Interface during Sintering and Cell Operation

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3674
Author(s):  
Mélanie François ◽  
Maria Paola Carpanese ◽  
Olivier Heintz ◽  
Victoire Lescure ◽  
Davide Clematis ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Perovskite Phase ◽  
Tape Casting ◽  
Chemical Degradation ◽  
Doped Ceria ◽  
Sintering Process ◽  
X Ray ◽  
Cell Testing ◽  
Complete Cell ◽  
Degradation Of Materials

A complete cell consisting of NiO-Ce0.8Sm0.2O3−δ//Ce0.8Sm0.2O3−δ//(La0.6Sr0.4)0.95Co0.2Fe0.8O3−δ elaborated by a co-tape casting and co-sintering process and tested in operating fuel cell conditions exhibited a strong degradation in performance over time. Study of the cathode–electrolyte interface after cell testing showed, on one hand, the diffusion of lanthanum from (La0.6Sr0.4)0.95Co0.2Fe0.8O3−δ into Sm-doped ceria leading to a La- and Sm-doped ceria phase. On the other hand, Ce and Sm diffused into the perovskite phase of the cathode. The grain boundaries appear to be the preferred pathways of the cation diffusion. Furthermore, a strontium enrichment was clearly observed both in the (La0.6Sr0.4)0.95Co0.2Fe0.8O3−δ layer and at the interface with electrolyte. X-ray photoelectron spectroscopy (XPS) indicates that this Sr-rich phase corresponded to SrCO3. These different phenomena led to a chemical degradation of materials and interfaces, explaining the decrease in electrochemical performance.

Identifying a perovskite phase in rare-earth nickelates using X-ray photoelectron spectroscopy

2020 ◽  
Vol 20 (1) ◽  
pp. 102-105 ◽  
Author(s):  
Jin San Choi ◽  
Chang Won Ahn ◽  
Jong-Seong Bae ◽  
Tae Heon Kim
Keyword(s):  
Rare Earth ◽  
Photoelectron Spectroscopy ◽  
Perovskite Phase ◽  
X Ray

scholarly journals Fabrication of ZnO nanocatalyst as an excellent heterogeneous catalyst applicant for Methyl Orange dye degradation in aqueous medium.

2021 ◽  
Author(s):  
Zaheer Ahmed Mahar ◽  
Ghulam Qadir Shar ◽  
Aamna Balouch
Keyword(s):  
Methyl Orange ◽  
Aqueous Medium ◽  
Photoelectron Spectroscopy ◽  
Dye Degradation ◽  
Catalytic Efficiency ◽  
Chemical Degradation ◽  
X Ray ◽  
Nano Catalyst ◽  
Methyl Orange Dye ◽  
Short Time

Abstract The current paper describes the fabrication of an excellent and economical heterogeneous nanocatalyst for the degradation of methyl orange dye in aqueous medium. ZnO/PVP nanocatalyst has been successfully synthesized by the chemical degradation route, followed by ultrasonication. The size, shape and crystalline structure of synthesized ZnO/PVP nano composite was characterized by UV-visible spectroscopy, X-ray diffractometry, Dynamic Scattering Light, Zeta Potential, Fourier transform infrared spectroscopy, Scanning Electron Microscope, Energy Dispersive X-ray and X-ray photoelectron spectroscopy. To authenticate the catalytic efficiency of nanocatalyst, the fabricated ZnO/PVP nanocompoiste was screened for methyl orange dye degradation. Finally, synthesized nanocatalyst exhibited an admirable catalytic efficiency, above 98% of methyl orange degradation observed just in 90 seconds using least catalyst dose (150μg) in aqueous medium. The engineered ZnO/PVA nanocomposite shows several advantages over traditional methods for the degradation of hazard and toxic dyes, such as high percentage degradation, short time and minimum dose of nano catalyst and excellent reusability. It is suggested that this rare nanocatalyst may be used successfully on commercial level for degradation toxic pollutants.

NANOCOMPOSITE Al2O3–Y2O3 FILMS ON CARBON STEEL

2009 ◽  
Vol 16 (06) ◽  
pp. 797-800 ◽  
Author(s):  
FANG LI ◽  
MINGMING YAO ◽  
XUELEI PENG
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Steel ◽  
Photoelectron Spectroscopy ◽  
Mass Gain ◽  
Electrochemical Process ◽  
Sintering Process ◽  
X Ray ◽  
Gain Measurement ◽  
Scanning Electron

The nanocomposite Al 2 O 3– Y 2 O 3 films were prepared on the surface of carbon steel by an electrochemical process and a sintering process. High-resolution field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the films, indicating that the films have nanostructures and the deposited alumina layers have a composition close to the stoichiometry of Al 2 O 3. SEM and mass gain measurement are adopted to study the oxidation resistance of films on carbon steel. It is proved that this kind of film is effective in protecting the substrate from oxidation. The mechanisms accounting for such effects have been discussed.

scholarly journals Lanthanum based high surface area perovskite-type oxide and application in CO and propane combustion

2018 ◽  
Vol 34 (1) ◽  
pp. 31
Author(s):  
Paulo Roberto Nagipe Da Silva ◽  
Ana Brígida Soares
Keyword(s):  
Catalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Perovskite Phase ◽  
High Surface ◽  
High Surface Area ◽  
Propane Combustion ◽  
Total Oxidation ◽  
X Ray ◽  
Co Precipitation ◽  
Perovskite Type

The perovskite-type oxides using transition metals present a promising potential as catalysts in total oxidation reaction. The present work investigates the effect of synthesis by oxidant co-precipitation on the catalytic activity of perovskite-type oxides LaBO3 (B= Co, Ni, Mn) in total oxidation of propane and CO. The perovskite-type oxides were characterized by means of X-ray diffraction, nitrogen adsorption (BET method), thermo gravimetric and differential thermal analysis (ATG-DTA) and X-ray photoelectron spectroscopy (XPS). Through a method involving the oxidant co-precipitation it’s possible to obtain catalysts with different BET surface areas, of 33-44 m2/g, according the salts of metal used. The characterization results proved that catalysts have a perovskite phase as well as lanthanum oxide, except LaMnO3, that presents a cationic vacancies and generation for known oxygen excess. The results of catalytic test showed that all oxides have a specific catalytic activity for total oxidation of CO and propane even though the temperatures for total conversion change for each transition metal and substance to be oxidized.

Crystallization of BaTiO3 Thin Films Prepared by Metalorganic Decomposition with Hydrothermal Treatment at 140°C

2001 ◽  
Vol 688 ◽  
Author(s):  
Zhiqiang Wei ◽  
Minoru Noda ◽  
Masanori Okuyama
Keyword(s):  
Thin Films ◽  
Hydrothermal Treatment ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Perovskite Phase ◽  
Processing Temperature ◽  
Structural Development ◽  
X Ray ◽  
Inductively Coupled ◽  
Si Substrates

AbstractBaTiO3 (BTO) thin films with perovskite structure have been prepared on Pt/Ti/SiO2/Si substrates using a combined process of a conventional MOD (metal organic decomposition) process and a hydrothermal treatment. The BTO thin films with polycrystalline structure are grown on Pt/Ti/SiO2/Si substrates at a processing temperature of 140°C. The structural development, stoichiometry, spectroscopic, and dielectric properties of the BTO thin films have been systematically investigated. X-ray diffraction patterns show that well-developed crystallites with a pure perovskite phase have been formed. ICP (Inductively coupled plasma) and XPS (x-ray photoelectron spectroscopy) results show that stoichiometric BTO thin films were obtained.

Low-temperature preparation and structural characterization of Pr-doped ceria solid solutions

2002 ◽  
Vol 17 (4) ◽  
pp. 797-804 ◽  
Author(s):  
E. López-Navarrete ◽  
A. Caballero ◽  
A. R. González-Elipe ◽  
M. Ocaña
Keyword(s):  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Heating Temperature ◽  
Doped Ceria ◽  
X Ray ◽  
Ceria Solid Solutions ◽  
Low Temperature Preparation ◽  
Distribution Composition ◽  
X Ray Absorption

We report a method for preparing Pr-doped ceria by pyrolysis at 600 °C of aerosols consisting of aqueous solutions of Ce(III) nitrate and Pr(III) chloride. This procedure involves an important decrease of the temperature of solid solution formation (several hundred degrees) when compared with the ceramic and other previously reported methods, and does not require the addition of fluxes. The prepared samples and their products after thermal treatment were characterized in terms of particle shape and size distribution, composition, and crystalline structure. The color properties of these solid solutions were also evaluated as a function of the heating temperature and composition; the optimum red pigment was obtained for samples with a Pr/Ce mole ratio = 0.063 heated for 3 h at 600 °C. The oxidation state of the Pr cations and their distribution in the CeO2 matrix were investigated by x-ray absorption near-edge spectroscopy and x-ray photoelectron spectroscopy. A mixture of trivalent and tetravalent Pr was detected in all studies samples. The Pr(IV)/Pr(III) ratio increased as the Pr content or the heating temperature increased. These Pr(III) cations were found to be mainly located in the particles' outer layers, in which an enrichment of Pr was detected for all samples heated at 600 °C. The further calcination of the pigments at 1200 °C gave rise to a certain diffusion of the Pr cations toward the particle core, which was more significant for the sample with the highest Pr content (Pr/Ce mole ratio 4 0.091).

Preparation of Perovskite Conductive LaNiO3 Films by Sol-Gel Techniques

2006 ◽  
Vol 933 ◽  
Author(s):  
Pei-Ying Lai ◽  
Jen-Sue Chen
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Metallic Thin Films ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Metallic Oxide ◽  
X Ray

ABSTRACTMetallic thin films of LaNiO3 (LNO) have been prepared by the sol-gel method using lanthanum nitrate [La(NO3)3·6H2O] and nickel acetate [Ni(CH3COO)2·4H2O] as raw materials. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and electrical measurements were used to characterize the multilayer LNO thin films. The perovskite phase appears after annealing at temperatures above 600 °C. LNO thin films are n-type metallic oxide. The lowest resistivity is 621 °Ω-cm after annealing at 600 °C, and the carrier concentration is 6.09×1022/cm3.

scholarly journals In operando x-ray photoelectron spectroscopy studies of H2 oxidation and H2O electrolysis on gadolinia-doped ceria electrodes

2020 ◽  
Vol 3 (1) ◽  
pp. 014004
Author(s):  
Lei Wang ◽  
Yi Yu ◽  
Karen J Gaskell ◽  
Ethan J Crumlin ◽  
Zhi Liu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Doped Ceria ◽  
X Ray ◽  
In Operando ◽  
Spectroscopy Studies ◽  
H2 Oxidation

Phase Transformation of Cu-Mo-C Powder during Mechanical Alloying and Annealing Process

2011 ◽  
Vol 233-235 ◽  
pp. 1678-1683
Author(s):  
Ke Sheng Zuo ◽  
Sheng Qi Xi ◽  
Jing En Zhou
Keyword(s):  
Phase Transformation ◽  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Graphite Powder ◽  
High Energy ◽  
Milling Process ◽  
Carbon Powder ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray

The allotropes of graphite and activated carbon were mixed with Cu and Mo powder, respectively. And the two groups of mixtures were high-energy milled and annealed. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and DSC/TG were used to investigate the phase transformation during the milling and sintering process. For both groups of powder milled, Mo was hard to dissolve in Cu, and C mainly congregated in the surface of Cu powder. When Cu-Mo-graphite powder as milled was annealed, Mo2C was formed. In comparison to Cu-Mo-graphite alloyed powder, Cu-Mo-activated carbon powder partially formed Cu oxide and Mo oxide with higher binding energy during milling process, which caused higher reduction temperature of Cu oxide and reaction temperature of Mo2C.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

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