scholarly journals Microstructural Changes in La0.5Ca0.5Mn0.5Fe0.5O3 Solid Solutions under the Influence of Catalytic Reaction of Methane Combustion

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 563
Author(s):  
Evgeny Yu. Gerasimov ◽  
Vladimir A. Rogov ◽  
Igor P. Prosvirin ◽  
Lyubov A. Isupova ◽  
Sergey V. Tsybulya
Keyword(s):  
Methane Oxidation ◽  
Solid Solutions ◽  
Perovskite Structure ◽  
Oxidation Reaction ◽  
Perovskite Phase ◽  
Reaction Medium ◽  
Methane Combustion ◽  
Planar Defects ◽  
In Situ Xrd

This article attempts to study changes in the microstructure of solid solutions with the perovskite structure La0.5Ca0.5Mn0.5Fe0.5O3 under the action of the methane oxidation reaction medium. By the methods of XRD, XPS and HRTEM the initial condition of the structure and the surface of the perovskite were both investigated. A feature of the structure of this solid solution is the presence of planar defects in the direction of the planes (101). After the methane oxidation reaction, a similar study of perovskite structure was conducted to obtain the changes. It was shown that under the action of the reaction medium, Ca1−xMnxO particles form on the surface of the perovskite phase, while planar defects in La0.5Ca0.5Mn0.5Fe0.5O3 structure remain. In situ XRD experiments on perovskite calcination in helium current up to 750 °C showed the formation of a similar Ca1−xMnxO phase on the perovskite surface.

scholarly journals Structural Insight into La0.5Ca0.5Mn0.5Co0.5O3 Decomposition in the Methane Combustion Process

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2283
Author(s):  
Olga Nikolaeva ◽  
Aleksandr Kapishnikov ◽  
Evgeny Gerasimov
Keyword(s):  
Solid Solution ◽  
Catalyst Deactivation ◽  
Combustion Process ◽  
Methane Combustion ◽  
Large Loss ◽  
In Situ Xrd ◽  
Oxide Particles ◽  
Structural Insight ◽  
Insight Into

Perovskite-like solid solution La0.5Ca0.5Mn0.5Co0.5O3 was tested during the total methane combustion reaction. During the reaction, there is a noticeable decrease in methane conversion, the rate of catalyst deactivation increasing with an increase in temperature. The in situ XRD and HRTEM methods show that the observed deactivation occurs as a result of the segregation of calcite and cobalt oxide particles on the perovskite surface. According to the TGA, the observed drop in catalytic activity is also associated with a large loss of oxygen from the perovskite structure.

In Situ XRD and In Situ IR Spectroscopic Analyses of Structural Change of Goethite in Methane Oxidation

2001 ◽  
Vol 156 (1) ◽  
pp. 225-229 ◽  
Author(s):  
Masahiro Katoh ◽  
Masanao Orihara ◽  
Toshihiro Moriga ◽  
Ichiro Nakabayashi ◽  
Shigeru Sugiyama ◽  
...  
Keyword(s):  
Structural Change ◽  
Methane Oxidation ◽  
In Situ Xrd ◽  
Spectroscopic Analyses ◽  
In Situ Ir ◽  
Ir Spectroscopic

scholarly journals Au Modified F-TiO2 for Efficient Photocatalytic Synthesis of Hydrogen Peroxide

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3844
Author(s):  
Lijuan Li ◽  
Bingdong Li ◽  
Liwei Feng ◽  
Xiaoqiu Zhang ◽  
Yuqian Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction System ◽  
Reaction Medium ◽  
Pure Tio2 ◽  
H2o2 Production ◽  
Tio2 Photocatalyst ◽  
H2o2 Decomposition ◽  
Spin Resonance ◽  
Photocatalytic Synthesis

In this work, Au-modified F-TiO2 is developed as a simple and efficient photocatalyst for H2O2 production under ultraviolet light. The Au/F-TiO2 photocatalyst avoids the necessity of adding fluoride into the reaction medium for enhancing H2O2 synthesis, as in a pure TiO2 reaction system. The F− modification inhibits the H2O2 decomposition through the formation of the ≡Ti–F complex. Au is an active cocatalyst for photocatalytic H2O2 production. We compared the activity of TiO2 with F− modification and without F− modification in the presence of Au, and found that the H2O2 production rate over Au/F-TiO2 reaches four times that of Au/TiO2. In situ electron spin resonance studies have shown that H2O2 is produced by stepwise single-electron oxygen reduction on the Au/F-TiO2 photocatalyst.

Zirconium phase transformations observed by “in-situ” XRD analysis

Vacuum ◽  
2012 ◽  
Vol 86 (6) ◽  
pp. 785-788 ◽  
Author(s):  
Jan Riha ◽  
Pavol Sutta ◽  
Andrej Vincze ◽  
Rostislav Medlin
Keyword(s):  
Phase Transformations ◽  
Xrd Analysis ◽  
In Situ Xrd

In situ mercaptosilane-assisted confinement of Pd nanoparticles in Beta for high-efficient methane oxidation

2021 ◽  
Author(s):  
Liling Zhang ◽  
Junfei Chen ◽  
Haolin Yang ◽  
Xiaohan Wang ◽  
Zebao Rui
Keyword(s):  
Methane Oxidation ◽  
Pd Nanoparticles ◽  
High Efficient

Evolution of Phase Transformation Behavior in Li(Mn1.5Ni0.5)O4 Cathodes Studied By In Situ XRD

2011 ◽  
Vol 158 (8) ◽  
pp. A890 ◽  
Author(s):  
Kevin Rhodes ◽  
Roberta Meisner ◽  
Yoongu Kim ◽  
Nancy Dudney ◽  
Claus Daniel
Keyword(s):  
Phase Transformation ◽  
Transformation Behavior ◽  
Phase Transformation Behavior ◽  
In Situ Xrd

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
Dsc Measurements ◽  
Transmission Window

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

Local decomposition of solid solutions, nanostructures and optical materials with negative refractive index

2016 ◽  
Vol 30 (07) ◽  
pp. 1650088
Author(s):  
Valeriy M. Ishchuk ◽  
Vladimir Sobolev
Keyword(s):  
Refractive Index ◽  
Electric Conductivity ◽  
Solid Solutions ◽  
Lead Zirconate Titanate ◽  
Perovskite Structure ◽  
Optical Materials ◽  
Negative Refractive Index ◽  
Lead Zirconate ◽  
The State ◽  
Interphase Boundaries

In this paper, a possibility of use of the controlled decomposition of solid solutions of oxides with perovskite structure in the state of coexisting domains of the antiferroelectric (AFE) and ferroelectric (FE) phases for manufacturing materials with the negative refractive index is demonstrated. The lead zirconate titanate-based solid solutions are considered as an example of substances suitable for creation of such materials. Manufactured composites constitute a dielectric AFE matrix with a structure of conducting interphase boundaries separating domains of the FE and AFE phases. The electric conductivity of the interphase boundaries occurs as a result of the local decomposition of the solid solutions in the vicinity of these boundaries. The decomposition process and consequently the conductivity of the interphase boundaries can be controlled by means of external influences.

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