scholarly journals The Influence Of NO/O2 On The NOx Storage Properties Over A Pt-Ba-Ce/γ-Al2O3 Catalyst

2019 ◽  
Vol 17 (1) ◽  
pp. 1459-1465
Author(s):  
Xuedong Feng ◽  
Jing Yi ◽  
Peng Luo
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
No Oxidation ◽  
Test Results ◽  
X Ray Diffraction ◽  
Storage Performance ◽  
Transmission Electron ◽  
Temperature Programmed ◽  
Physical And Chemical ◽  
Al2o3 Catalyst

AbstractWith the purpose of studying the influence of NO/O2 on the NOx storage activity, a Pt-Ba-Ce/γ-Al2O3 catalyst was synthesized by an acid-aided sol-gel method. The physical and chemical properties of the catalyst were characterized by X-ray diffraction (XRD) and Transmission Electron Microscope (TEM) methods. The results showed that the composition of the catalyst was well-crystallized and the crystalline size of CeO2 (111) was about 5.7 nm. The mechanism of NO and NO2 storage and NOx temperature programmed desorption (NO-TPD) experiments were investigated to evaluate the NOx storage capacity of the catalyst. Pt-Ba-Ce/γ-Al2O3 catalyst presented the supreme NOx storage performance at 350℃, and the maximum value reached to 668.8 μmol / gcat. Compared with O2-free condition, NO oxidation to NO2 by O2 had a beneficial effect on the storage performance of NOx. NO-TPD test results showed that the NOx species stored on the catalyst surface still kept relatively stable even below 350℃.

Influence of tungsten sources on the synthesis and properties of ammonium dioxothiotungstate

2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Yunfei Bi ◽  
Shuangqin Zeng ◽  
Dadong Li ◽  
Hong Nie
Keyword(s):  
Tungsten Oxide ◽  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Detailed Characteristic ◽  
Temperature Programmed ◽  
Physical And Chemical ◽  
And Chemical Properties

AbstractAmmonium dioxothiotungstate was synthesized using different tungsten sources and characterized in detail by powder X-ray diffraction, energy dispersive X-ray spectrometry, transmission electron microscopy, nitrogen adsorption, and temperature-programmed sulfidation. It was found that tungsten oxide nanobelts are superior to ammonium metatungstate as tungsten source for the synthesis of ammonium dioxothiotungstate due to a time-consuming aging step being excluded from the synthesis route. Moreover, detailed characteristic data reveal that, when tungsten oxide nanobelts are used, the physical and chemical properties of the resulting ammonium dioxothiotungstate including particles size, specific surface area, and sulfidation pattern were improved. Also, the hydrodesulfurization measurements showed higher catalytic activity and balanced selectivity of the resulting ammonium dioxothiotungstate.

Synthesis and Characterization of Zn doped Li(Li0.21Mn0.54Ni0.125Co0.125)O2 as the Layer Materials For Battery Applications

2018 ◽  
Vol 21 (2) ◽  
pp. 127-131
Author(s):  
S. Rumh. Kadhim ◽  
Reihan Etefagh ◽  
H. Arabi
Keyword(s):  
Infrared Spectroscopy ◽  
Chemical Elements ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Physical And Chemical ◽  
And Chemical Properties

In this paper, pure and impure nanopowders of Li(Li0.021Mn0.54Ni0.125Co0.125)O2 were prepared with different percentages (x=0.02%, 0.05%, 0.075%, 0.10%) of Zn impurity by sol-gel method, and the effect of different percentages were investigated on the structural, physical and chemical properties of the samples. These properties of samples characterized by X-ray diffraction (XRD), field-scattering microscopy (FESEM), X-ray energy spectroscopy (EDS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), infrared spectroscopy (FTIR), and the results of characterization were investigation. All the reflection peaks indicate that the samples have standard α-NaFeO2 layered structure with the space group R3m, except for the super lattice ordering between 22°-25°.The FESEM images have shown that these nanoparticles have Hexagonal structures for doped and undoped nanopowders. The particle size of nanopowders in the range of 30-80 nm the chemical analysis of EDS has proven the presence of Zn in the samples. TG /DTA measurements showed weight loss in pure and impure of nanopowders. In infrared spectroscopy (FTIR), the connection bonds and chemical elements used in these nanopowders have been investigated.

scholarly journals Evaluation of NO Oxidation Properties over a Mn-Ce/γ-Al2O3Catalyst

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Pan Wang ◽  
Peng Luo ◽  
Junchen Yin ◽  
Lili Lei
Keyword(s):  
Electron Microscope ◽  
Sol Gel ◽  
Diesel Oxidation Catalyst ◽  
No Oxidation ◽  
Oxidation Catalyst ◽  
X Ray Diffraction ◽  
Oxidation Activity ◽  
Transmission Electron ◽  
Diesel Oxidation ◽  
Oxidation Properties

With the purpose of studying the effect of diesel oxidation catalyst (DOC) on the NO oxidation activity, a series ofxMn10Ce/γ-Al2O3(x= 4, 6, 8, and 10) catalysts were synthesized by acid-aided sol-gel method. The physicochemical properties of the catalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and Transmission Electron Microscope (TEM). Result showed that the crystalline size of MnOxand CeO2ranges from 5 nm to 30 nm and manganese existed mainly in the catalysts in the form of manganese dioxide. Moreover, NO oxidation experiments were carried out to evaluate the activity of the catalysts; according to the results, 6Mn10Ce/γ-Al2O3catalyst showed the supreme NO oxidation activity with a NO to NO2conversion rate of 83.5% at 300°C. Compared to 500 ppm NO inlet concentration, the NO conversion was higher than that of 750 and 1000 ppm NO over 6Mn10Ce/γ-Al2O3catalyst in the temperature range of 150–300°C.

Investigating the properties and performance of 3A molecular sieves as an adsorbent to prevent coke formation in olefin dehydration process

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zoya Moslempour ◽  
Sepehr Sadighi ◽  
Ali Dashti ◽  
Ali Ahmadpour
Keyword(s):  
Molecular Sieves ◽  
Molecular Sieve ◽  
Coke Formation ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Na Ions ◽  
Temperature Programmed ◽  
And Performance ◽  
Physical And Chemical

Abstract To study the affinity of 3A aluminosilicate adsorbents to prevent oligomerization of olefin molecules and forming green oil, physical and chemical properties of 3A molecular sieves are measured by using characterization techniques such as temperature-programmed desorption (TPD), nitrogen (N2) and water adsorptions, X-ray diffraction (XRD), X-ray fluorescence (XRF), crushing strength, and carbon dioxide (CO2) adsorption. Moreover, coke formation affinities of the understudy adsorbents are evaluated in a bench-scale system using 1-butene and 1,3-butadiene at temperatures of 220 and 260 °C, and outcomes are validated against the actual data gathered from an industrial scale olefin dehydration plant. Results confirm that the type of binder and the amount of ion exchange affect the performance of a 3A molecular sieve nominated for dehydrating olefinic streams. The binder with the least amount of acidity is preferred, and at least 35% of Na ions of the 4A zeolite should be exchanged with K ions to make it applicable for synthesizing an appropriate 3A molecular sieve. Furthermore, to control the oligomerization and inhibit green oil formation, the CO2 adsorption and acidity of Trisiv shape molecular sieves with the sizes of 1/4 inch should be less than 0.5 wt % and 1.7 mmol NH3/g, respectively. For extrudate shape with the sizes of 1/16 inch CO2 adsorption and acidity should be less than 0.2 wt % and 2.2 mmol NH3/g, respectively.

Synthesis and Characterization of Cassava Starch Nanocrystals by Hydrolysis Method

2015 ◽  
Vol 1113 ◽  
pp. 446-452 ◽  
Author(s):  
Nur Shazrynda Md Shahrodin ◽  
Abdul Razak Rahmat ◽  
Agus Arsad
Keyword(s):  
Chemical Properties ◽  
Cassava Starch ◽  
High Yield ◽  
X Ray Diffraction ◽  
Hydrolysis Method ◽  
Transmission Electron ◽  
Hydrolysis Process ◽  
20 Nm ◽  
Physical And Chemical ◽  
Starch Nanocrystals

Cassava starch nanocrystals (CSN) has not been reported in open literature, although other starches such as rice, corn, potato and bean were widely used as the main material. Thus, the objective of this research was to investigate the possibility of synthesizing high yield of CSN at different concentration of sulphuric acid (H2SO4). The physical and chemical properties of synthesize CSN was also investigated. Synthesized CSN was prepared by hydrolysing native cassava starch (NCS) with several concentration of H2SO4 (2.8 M, 3.0 M, 3.2 M and 3.4 M). The acid hydrolysis process took five days with continuous stirring speed of 300 to 400 rpm, with constant temperature of 37 °C. The hydrolysed solution of CSN underwent centrifuging process with distilled water until neutral to make sure that no acid residues remain in the CSN solution. The CSN precipitate was dried in an oven over night at 60 °C. The highest yield (1.1 %) produced was from 3.4 M CSN. Morphology test by Transmission Electron Microscopy indicated that the samples have been destructed and degraded to be nanocrystals with a size range of 5 - 20 nm. X-ray Diffraction (XRD) and 13C Nuclear Magnetic Resonance (NMR) were used to indicate the type of crystallinity for both NCS and CSN.

Preparation of Pd/γ-Al2O3 Nanocatalyst and Characterization by X-Ray Diffraction and Transmission Electron Microscope

2013 ◽  
Vol 685 ◽  
pp. 312-315
Author(s):  
Karim. H. Hassan
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Selective Hydrogenation ◽  
Chemical Properties ◽  
Impregnation Method ◽  
Activated Alumina ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Physical And Chemical

In petrochemical industry, and mainly in ethylene production plants, acetylene presents in trace amount in ethylene gas and causes a serous problems owing to it is higher activity and being explosive at certain concentration limits with air, so it has to be converted to ethylene in selective hydrogenation. Three selective hydrogenation nanocatalysts Pd/γ-Al2O3 that contain 0.03 %, 0.05% and 0.07 wt % of palladium loaded on activated alumina were prepared by impregnation method. They were characterized for physical and chemical properties and structurally by X-ray diffraction, metal dispersion, and transmission electron microscope.

Mineralogy of volcanically derived alluvial soils at Moshi, Tanzania

Soil Research ◽  
2016 ◽  
Vol 54 (8) ◽  
pp. 926
Author(s):  
T. S. Taylor ◽  
J. C. Hughes ◽  
L. W. Titshall
Keyword(s):  
Electron Microscopy ◽  
Clay Fraction ◽  
Chemical Properties ◽  
Volcanic Glass ◽  
X Ray Diffraction ◽  
Surface Areas ◽  
Transmission Electron ◽  
Physical And Chemical ◽  
Extractable Iron ◽  
And Chemical Properties

Despite intensive commercial agriculture in the rift zone of Tanzania, mineralogical studies on the soils influenced by volcanic parent materials are scarce. A mineralogical investigation of the soils and two buried ash layers from an irrigated sugar estate was undertaken using X-ray diffraction, transmission electron microscopy and measurements of extractable iron, aluminium and silicon and the specific surface area (SSA) of the clay fraction. The dominant mineral in the sand and silt fractions was sanidine. The clay fractions contained mainly high-defect kaolin, illite and K-feldspar, with small amounts of calcite, talc and gibbsite in some samples. Electron microscopy revealed the presence of tubular and spheroidal halloysite and <0.5µm kaolinite crystals, as well as nanocrystalline material, probably allophane, and volcanic glass. The amounts of ferrihydrite (0.34–1.84%) and allophane (0.52–6.84%) were low in the soils but higher in the buried ash layers. The surface areas of the clay fractions were high (up to 145m2g–1) and it was calculated that 5% allophane constituted 22% of the total SSA. Although all soils were dominated by halloysite and small kaolinite particles, it is likely that the small amounts of allophane with high SSA has a strong effect on their physical and chemical properties.

Characterization of Y/TiO2 Nanoparticles and their Reactivity for CO2 Photoreduction

2011 ◽  
Vol 55-57 ◽  
pp. 1506-1510 ◽  
Author(s):  
Jing Wei ◽  
Xin Tan ◽  
Tao Yu ◽  
Lin Zhao
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Illumination ◽  
Transmission Electron ◽  
And Chemical Properties

A series of Y/TiO2nanoparticles (NPs) were synthesized via sol-gel method. The crystal structures, morphologies and chemical properties were characterized using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). We investigated the effects of different doping amounts of Y on the reaction of CO2photoreduction. The results shown that 0.1 wt.%Y/TiO2(0.1YT) performed the highest photocatalytic activity, which yielded 384.62 µmol/g∙cat. formaldehyde after 6 h of UV illumination.

CHARACTERISTICS OF THIN FILMS SYNTHESIZED FROM NANO BOEHMITE AND ORGANOALKOXYSILANE

2010 ◽  
Vol 17 (03) ◽  
pp. 277-281 ◽  
Author(s):  
HOYYUL PARK ◽  
MYEONGSANG AHN ◽  
MOONKYONG NA
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Reaction Times ◽  
Chemical Properties ◽  
Surface Hydrophobicity ◽  
Organic Hybrid ◽  
Transmission Electron ◽  
Hybrid Thin Films ◽  
Physical And Chemical ◽  
Nano Sol

We investigated the properties of inorganic–organic hybrid thin films prepared by sol–gel reaction. Sol solutions were synthesized by using two kinds of nanosized boehmite and methyltrimethoxysilane (MTMS) in variation with the amount of MTMS at different reaction times. Boehmite nano sol of spherical and fibrous shapes was used as inorganic material, and MTMS was used as organic material. The morphology of boehmite nano sol powder was observed by transmission electron microscopy. Coating sols were prepared from boehmite sol and MTMS by sol–gel reaction. Physical and chemical properties of thin films prepared from boehmite and MTMS sols were investigated. Surface hydrophobicity, roughness, thickness, thermal resistance and electrical resistivity of boehmite/MTMS thin films were investigated.

scholarly journals Sol-Gel Synthesized Semiconductor Oxides in Photocatalytic Degradation of Phenol

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Maria K. Cherepivska ◽  
Roman V. Prihod’ko
Keyword(s):  
Photocatalytic Degradation ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Semiconductor Oxides ◽  
Titanium Dioxide Sample ◽  
Vis Spectroscopy ◽  
Physical And Chemical ◽  
And Chemical Properties

Effectiveness of photocatalytic degradation of phenol in aqueous solution using semiconductor oxides (SO) prepared by a sol-gel method was examined. The physical and chemical properties of synthesized catalysts were investigated by X-ray diffraction (XRD), diffuse reflectance UV-Vis spectroscopy (DRS), and N2-adsorption measurements. The optimal conditions of the photocatalytic degradation of phenol using prepared titanium dioxide sample were defined.

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