scholarly journals Dry Reforming of Methane on Carriers and Oxide Catalysts to Synthesis-Gas

2018 ◽  
Vol 20 (2) ◽  
pp. 131 ◽  
Author(s):  
K. Dossumov ◽  
Y. Yergaziyeva ◽  
L. Myltykbayeva ◽  
M. Telbayeva
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Synthesis Gas ◽  
Space Velocity ◽  
Dry Reforming Of Methane ◽  
Carbon Dioxide Conversion ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Conversion Of Methane ◽  
Al2o3 Catalyst

The catalytic activity of carriers: θ‒Al2O3, γ‒Al2O3, 5A, 4A, 3A and 13X and the oxides of metals of variable valency ‒ NiO, La2O3, CuO, MoO3, MgO, V2O5, WO3, CoO, Cr2O3, ZnO, ZrO2, CeO2, Fe2O3, supported on the effective carrier γ‒Al2O3 by the method of capillary impregnation of the support with solutions of nitric salts of metals were investigated in the process of carbon dioxide conversion of methane (DRM). The optimal technological regimes for the process were: the reaction temperature -800 °C, the space velocity of the initial reactants ‒ 1500 h-1 with a methane to carbon dioxide ratio equal to 1. It was found that among the studied catalysts the highest activity is shown by the NiO/γ‒Al2O3 catalyst, where the yields of hydrogen and carbon monoxide reaches 45.4 and 42.4% by volume, respectively, when methane conversion is 89%. The XRF method showed that the content of alumina and nickel oxide after the reaction remained unchanged at 96.7 and 3.0%, respectively. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), small angle X-ray scattering (XRS) determined that nickel-containing NiO/γ‒Al2O3 catalyst form nickel nanoparticles (6.4‒10 and 50‒150 nm) and a uniform their distribution on the surface of the carrier takes place. These physical chemical characteristics have a positive effect on the activity of NiO/γ‒Al2O3 catalyst in the process of carbon dioxide conversion of methane to synthesis gas.

scholarly journals Preparation of synthesis gas by methane dry reforming on fiberglass catalysts

2018 ◽  
pp. 28-38
Author(s):  
Zhanar Kudyarova ◽  
Anatoly Mironenko ◽  
Asel Kazieva ◽  
V. Аntonuk ◽  
Zulkhair Mansurov
Keyword(s):  
Carbon Dioxide ◽  
Synthesis Gas ◽  
Phase Method ◽  
Carbon Dioxide Conversion ◽  
Active Components ◽  
Solution Combustion ◽  
X Ray ◽  
Co Catalysts ◽  
Lanthanum Phosphate ◽  
Conversion Of Methane

The application field of materials based on lanthanum orthophosphate (LaPO4) including nanomaterials, has been permanently extending recently. The high level of mechanical properties and the compatibility with numerous oxides make it possible to consider the possibility of using lanthanum orthophosphate as a composite material for construction purposes. This application is particularly promising when nanoparticles with quasi-1D morphology (nanorods) are used. The high isomorphic capacity of the LaPO4-based phase for alkaline-earth ions and ions of lanthanides and actinides, high chemical stability, and high radiation hardness make promising the application of this compound as a matrix for immobilization of radioactive wastes. The possibility of obtaining lanthanum phosphate (LaPO4) by the hydrothermal method is considered in the work. Effects of pH, temperature and time of processing of hydrothermal synthesis on the morphology and structure of monostructured lanthanum phosphate are studied. It has been established that, with the increase of pH, the morphology of phosphate changed, the size of the crystallites increased, while the crystal structure changed from hexagonal to monoclinic. The catalytic activity of nanostructured low-percentage Mg-Ni-Co-catalysts based on high-temperature KT-11-TO grade fiberglass obtained by “solution combustion” (SC) method was studied at carbon dioxide conversion of methane (CDCM). The physico-chemical characteristics of samples were studied using X-ray diffraction phase analysis, temperature-programmed reduction (TPR) and transmission electron microscopy (TEM). The X-ray phase method showed the formation of several phases during the synthesis: NiCo2O4, 3CoO·5NiO, MgO, and Co3O4. According to TEM, active catalyst particles have a size of 5-10 nm proving the nanoscale size of the active component. TPR method showed the shift of maximum hydrogen absorption to higher temperatures. Apparently, it occurs due to the interaction of the active components with the carrier till the new phase formation. On the basis of the gas chromatographic analysis the high activity of fiberglass catalysts at the carbon dioxide conversion of methane into synthesis gas with a conversion of the initial components close to ~ 100% was disclosed. The optimal technological conditions for the CDCM process were established – a temperature in the range of 850-900°С, the volumetric rate of initial reactants 4000-10000 h-1 with a ratio of methane to carbon dioxide equal to 1.

Carbon Dioxide – Dilated Block Copolymer Templates for Nanostructured Materials

1999 ◽  
Vol 584 ◽  
Author(s):  
Garth D. Brown ◽  
James J. Watkins
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Transmission Electron Microscopy ◽  
Organometallic Compounds ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Metal Precursors ◽  
Polymer Semiconductor ◽  
Polymer Metal

AbstractPeriodic polymer/metal (Pt or Ag) and polymer/semiconductor (PbS) nanocomposites are prepared using block copolymers dilated with carbon dioxide (CO2) as templates. Specifically, organometallic compounds (metal precursors) are dissolved into supercritical CO2 and infused into polystyrene-block-poly(acrylic acid) or polystyrene-block-poly(vinylpyridine) copolymers. Upon infusion, the acid or pyridine block selectively binds the metal precursor. The excess is removed from the polystyrene phase by subsequent CO2 extraction. Reduction of the bound organometallic with hydrogen or hydrogen sulfide yields the desired metal or semiconductor clusters, which are confined to the precursor-binding domain and remain positioned on the copolymer lattice. The composites are characterized by transmission electron microscopy, x-ray scattering and electron diffraction.

Carbon dioxide and methane adsorption over metal modified mesoporous SBA-15 silica

2017 ◽  
Vol 89 (4) ◽  
pp. 493-500 ◽  
Author(s):  
Vladimír Zeleňák ◽  
Jozef Magura ◽  
Adriána Zeleňáková ◽  
Romana Smolková
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Metal Ion ◽  
Nitrogen Adsorption ◽  
Methane Adsorption ◽  
Carbon Dioxide Adsorption ◽  
Metal Doping ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Adsorption Desorption

Abstract In the present study, mesoporous silica materials doped with metal ions (Al3+, Ti4+, Zr4+) were synthesized and characterized by a combination of various techniques, such as small angle X-ray scattering (SAXS), nitrogen adsorption/desorption at 77 K, elemental analysis, transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). It was shown that the metal ion doped samples retained their porous structure, which was similar to that of parent SBA-15. The synthesized M-SBA-15 samples (M=Al3+, Ti4+, Zr4+) were evaluated in terms of adsorption of carbon dioxide and methane at 303 K. It was observed, that metal doping enhances carbon dioxide adsorption in comparison with purely siliceous sample, while low effect of metal doping on methane adsorption was observed.

scholarly journals Study on Structure, Thermal Behavior, and Viscoelastic Properties of Nanodiamond-Reinforced Poly (vinyl alcohol) Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1426
Author(s):  
Tomáš Remiš ◽  
Petr Bělský ◽  
Tomáš Kovářík ◽  
Jaroslav Kadlec ◽  
Mina Ghafouri Azar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Single Step ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Primary Particles ◽  
Solution Casting Method ◽  
Average Size

In this work, advanced polymer nanocomposites comprising of polyvinyl alcohol (PVA) and nanodiamonds (NDs) were developed using a single-step solution-casting method. The properties of the prepared PVA/NDs nanocomposites were investigated using Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was revealed that the tensile strength improved dramatically with increasing ND content in the PVA matrix, suggesting a strong interaction between the NDs and the PVA. SEM, TEM, and SAXS showed that NDs were present in the form of agglomerates with an average size of ~60 nm with primary particles of diameter ~5 nm. These results showed that NDs could act as a good nanofiller for PVA in terms of improving its stability and mechanical properties.

scholarly journals Alpha helical surfactant-like peptides self-assemble into pH-dependent nanostructures

Soft Matter ◽  
2021 ◽  
Vol 17 (11) ◽  
pp. 3096-3104
Author(s):  
Valeria Castelletto ◽  
Jani Seitsonen ◽  
Janne Ruokolainen ◽  
Ian W. Hamley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Small Angle ◽  
Self Assembly ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Ph Dependent ◽  
Ray Scattering

A designed surfactant-like peptide is shown, using a combination of cryogenic-transmission electron microscopy and small-angle X-ray scattering, to have remarkable pH-dependent self-assembly properties.

Analysis of InGaN/GaN single quantum wells by X-ray scattering and transmission electron microscopy

2003 ◽  
Vol 240 (2) ◽  
pp. 297-300 ◽  
Author(s):  
T. M. Smeeton ◽  
M. J. Kappers ◽  
J. S. Barnard ◽  
M. E. Vickers ◽  
C. J. Humphreys
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Wells ◽  
Single Quantum ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Ray Scattering

Chemical Recovery Processes of CO2

2021 ◽  
Vol 25 (12) ◽  
pp. 30-37
Author(s):  
L.G. Pinaeva ◽  
A.S. Noskov
Keyword(s):  
Carbon Dioxide ◽  
Synthesis Gas ◽  
Methanol Synthesis ◽  
Dimethyl Carbonate ◽  
Chemical Recovery ◽  
Target Product ◽  
Stable Carbon ◽  
Carbon Dioxide Conversion ◽  
Recovery Processes ◽  
Motor Fuels

Existing (production of urea, dimethyl carbonate, polypropylene carbonate) and promising (production of methanol, synthesis gas, monomers dedicated to synthesis of polyurethanes and polycarbonate) chemical technologies which any, time soon, may become CO2 based economy for producing motor fuels and basic chemicals have been overviewed. Based on estimates of CO2 removals in these processes, it has been concluded that there is a potential for developing technologies to produce methanol from CO2 to a competitive cost of the target product. It is expected that interest in this process will decrease if stable carbon dioxide conversion catalysts for methane are introduced into the market.

Effect of MoO3 on the Catalytic Properties of NiO/Al2O3 in the Carbon Dioxide Conversion of Methane

2019 ◽  
Vol 55 (2) ◽  
pp. 137-142 ◽  
Author(s):  
K. Dossumov ◽  
G. E. Ergazieva ◽  
L. K. Myltykbaeva ◽  
M. M. Telbaeva ◽  
A. T. Batyrbaev
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Properties ◽  
Carbon Dioxide Conversion ◽  
Conversion Of Methane
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