Decomposition of Nickel(Ⅱ)−Ethylenediaminetetraacetic acid by Fenton−Like reaction over oxygen vacancies-based Cu−Doped Fe3O4@γ−Al2O3 catalyst: A synergy of oxidation and adsorption

Chemosphere ◽  
2019 ◽  
Vol 221 ◽  
pp. 563-572 ◽  
Author(s):  
Wuming Xie ◽  
Fengping Zhou ◽  
Xiaolin Bi ◽  
Dongdong Chen ◽  
Zijun Huang ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Ethylenediaminetetraacetic Acid ◽  
Al2o3 Catalyst

The Influence of Boria and EDTA on the Hydrodesulfurization Activity on CoMoS Supported Catalysts

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Matin Parvari ◽  
Peyman Moradi
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Supported Catalysts ◽  
Batch Reactor ◽  
Kinetic Constant ◽  
Order Kinetic ◽  
First Order ◽  
Pseudo First Order ◽  
Xrd Studies ◽  
Al2o3 Catalyst ◽  
Hydrodesulfurization Activity

The hydrodesulfurization of dibenzothiophene (HDS of DBT) in a high pressure batch reactor at 320°C was carried out over CoMo/Al2O3-B2O3 catalysts with different B2O3 contents (4, 10, and 16 wt%). Ethylenediaminetetraacetic acid (EDTA) with different EDTA/Co mole ratios (0.6, 1.2 and 1.8) was used as a chelating ligand during the preparation of CoMo/Al2O3-B2O3. XRD studies, FTIR, TPD of NH3, and BET experiments were used to investigate the catalyst samples. The results showed that the catalyst using the support with 4 wt% B2O3 and an EDTA/Co mole ratio of 1.2 had a hydrodesulfurization activity (in pseudo first order kinetic constant basis) value of ~2.96 times higher than that of the simple CoMo/Al2O3 catalyst.

scholarly journals Removal of VOCs by Ozone: n-Alkane Oxidation under Mild Conditions

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 506
Author(s):  
Alina I. Mytareva ◽  
Igor S. Mashkovsky ◽  
Sergey A. Kanaev ◽  
Dmitriy A. Bokarev ◽  
Galina N. Baeva ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Oxygen Vacancies ◽  
Oxide Catalyst ◽  
Catalytic Performance ◽  
High Concentration ◽  
Volatile Organic ◽  
Negative Effect ◽  
Manganese Oxide Catalyst ◽  
Conventional Solution ◽  
Al2o3 Catalyst

Volatile organic compounds (VOCs) have a negative effect on both humans and the environment; therefore, it is crucial to minimize their emission. The conventional solution is the catalytic oxidation of VOCs by air; however, in some cases this method requires relatively high temperatures. Thus, the oxidation of short-chain alkanes, which demonstrate the lowest reactivity among VOCs, starts at 250–350 °C. This research deals with the ozone catalytic oxidation (OZCO) of alkanes at temperatures as low as 25–200 °C using an alumina-supported manganese oxide catalyst. Our data demonstrate that oxidation can be significantly accelerated in the presence of a small amount of O3. In particular, it was found that n-C4H10 can be readily oxidized by an air/O3 mixture over the Mn/Al2O3 catalyst at temperatures as low as 25 °C. According to the characterization data (SEM-EDX, XRD, H2-TPR, and XPS) the superior catalytic performance of the Mn/Al2O3 catalyst in OZCO stems from a high concentration of Mn2O3 species and oxygen vacancies.

scholarly journals In-plasma-catalysis for NOx degradation by Ti3+ self-doped TiO2−x/γ-Al2O3 catalyst and nonthermal plasma

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24144-24155
Author(s):  
Xingdong Yang ◽  
Jiyan Qu ◽  
Linxi Wang ◽  
Jianhong Luo
Keyword(s):  
Oxygen Vacancies ◽  
Nonthermal Plasma ◽  
Band Width ◽  
Plasma Catalysis ◽  
Doped Tio2 ◽  
Degradation Effect ◽  
Al2o3 Catalyst ◽  
Catalysis Process

TiO2−x has a smaller forbidden band width, more abundant Ti3+ and oxygen vacancies, so as to obtain a better and more stable degradation effect of NOx in plasma-catalysis process.

scholarly journals Catalytic Combustion of Toluene over Highly Dispersed Cu-CeOx Derived from Cu-Ce-MOF by EDTA Grafting Method

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 519
Author(s):  
Wenjie Sun ◽  
Yijia Huang ◽  
Xiaomin Li ◽  
Zhen Huang ◽  
Hualong Xu ◽  
...  
Keyword(s):  
Catalytic Combustion ◽  
Oxygen Vacancies ◽  
Diffuse Reflectance ◽  
Ethylenediaminetetraacetic Acid ◽  
Deep Oxidation ◽  
In Situ Drifts ◽  
Metal Organic ◽  
Diffuse Reflectance Infrared ◽  
Key Steps

In this work, Cu-CeOx-MOF catalysts with well-dispersed Cu in different contents were synthesized via the ethylenediaminetetraacetic acid (EDTA) grafting method. EDTA was grafted in Ce-MOF-808 to anchor Cu and then the metal-organic frameworks (MOFs) were utilized as sacrificial template to form highly performed Cu-CeOx-MOF for toluene catalytic combustion. In this series of samples, Cu-CeOx-MOF-0.2 had a higher ratio of Oα/(Oα+Oβ), more oxygen vacancies and performed better low-temperature reducibility. Cu-CeOx-MOF-0.2 showed outstanding catalytic activity and stability. The T90 (temperature when toluene conversion achieved 90%) of Cu-CeOx-MOF-0.2 was 226 °C at 60,000 mL/(gcat∙h). In situ diffuse reflectance infrared transform spectroscopy (in situ DRIFTS) results revealed that the opening of aromatic ring and the deep oxidation of carboxylate were key steps for toluene catalytic combustion over Cu-CeOx-MOF-0.2.

scholarly journals Structure of LaSrMO4(M = Mn, Fe, Co, Ni, Cu) and their catalytic properties in the total oxidation of hexane

2006 ◽  
Vol 71 (10) ◽  
pp. 1049-1059 ◽  
Author(s):  
H. Zhong ◽  
R. Zeng
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
Oxygen Vacancies ◽  
Mixed Oxides ◽  
Ethylenediaminetetraacetic Acid ◽  
Catalytic Properties ◽  
Bet Surface Area ◽  
Total Oxidation ◽  
Catalytic Behavior ◽  
Perovskite Type

Perovskite-type LaSrMO4 (M = Mn, Fe, Co, Ni, Cu) mixed oxides were prepared by the decomposition of amorphous citric and ethylenediaminetetraacetic acid complexes and investigated by the XRD, FTIR, BET, TPR, TPD and XPSmethods. Their catalytic behavior in the total oxidation of hexane was examined. The following activity order was found LaSrCoO4 > LaSrNiO4 > LaSrCuO4 > LaSrFeO4 > LaSrMnO4. This is explained in terms of oxygen vacancies and mobile lattice oxygen, particle size and BET surface area. .

Conditions for atomic imaging of mullite

1989 ◽  
Vol 47 ◽  
pp. 418-419
Author(s):  
T. A. Epicier ◽  
G. Thomas
Keyword(s):  
Oxygen Vacancies ◽  
High Resolution Electron Microscopy ◽  
Ceramic Materials ◽  
Work Conditions ◽  
Real Space ◽  
Potential Candidate ◽  
Silicate Mineral ◽  
Resolution Electron ◽  
The Subject ◽  
Aluminium Silicate

Mullite is an aluminium-silicate mineral of current interest since it is a potential candidate for high temperature applications in the ceramic materials field.In the present work, conditions under which the structure of mullite can be optimally imaged by means of High Resolution Electron Microscopy (HREM) have been investigated. Special reference is made to the Atomic Resolution Microscope at Berkeley which allows real space information up to ≈ 0.17 nm to be directly transferred; numerous multislice calculations (conducted with the CEMPAS programs) as well as extensive experimental through-focus series taken from a commercial “3:2” mullite at 800 kV clearly show that a resolution of at least 0.19 nm is required if one wants to get a straightforward confirmation of atomic models of mullite, which is known to undergo non-stoichiometry associated with the presence of oxygen vacancies.Indeed the composition of mullite ranges from approximatively 3Al2O3-2SiO2 (referred here as 3:2-mullite) to 2Al2O3-1SiO2, and its structure is still the subject of refinements (see, for example, refs. 4, 5, 6).

Conversion of fructose into methyl lactate over SnO2/Al2O3 catalystin flow regime

2020 ◽  
pp. 43-47
Author(s):  
S.V. Prudius ◽  
◽  
N.L. Hes ◽  
A.M. Mylin ◽  
V.V. Brei ◽  
...  
Keyword(s):  
Flow Reactor ◽  
Practical Interest ◽  
Dimethyl Acetal ◽  
Racemic Mixture ◽  
Process Conditions ◽  
Impregnation Method ◽  
Aqueous Methanol ◽  
Methyl Lactate ◽  
Al2o3 Catalyst ◽  
Target Reaction

In recent years, numerous researchers have focused on the development of catalytic methods for processing of biomass-derived sugars into alkyl lactates, which are widely used as non-toxic solvents and are the starting material for obtaining monomeric lactide. In this work, the transformation of fructose into methyl lactate on Sn-containing catalyst in the flow reactor that may be of practical interest was studied. The supported Sn-containing catalyst was ob-tained by a simple impregnation method of granular γ-Al2O3. The catalytic ex-periments were performed in a flow reactor at temperatures of 160-190 °C and pressure of 3.0 MPa. The 1.6-9.5 wt.% fructose solutions in 80% aqueous methanol were used as a reaction mixture. It was found that addition to a reac-tion mixture of 0.03 wt.% potassium carbonate leads to the increase in selec-tivity towards methyl lactate on 15% at 100% conversion of fructose. Prod-ucts of the target reaction С6Н12О6 + 2СН3ОН = 2С4Н8О3 + 2Н2О were ana-lyzed using 13C NMR method. The following process conditions for obtaining of 65 mol% methyl lactate yield at 100% fructose conversion were found: use of 4.8 wt.% fructose solution in 80% methanol, 180 °С, 3.0 МПа and a load on catalyst 1.5 mmol C6H12O6/mlcat/h at contact time of 11 minutes. The cata-lyst productivity is 2.0 mmol C4H8O3/mlcat/h and the by-productі are 1,3-dihydroxyacetone dimethyl acetal (20%) and 5-hydroxymethylfurfural (10%). It should be noted that a racemic mixture of L- and D-methyl lactates has been obtained by conversion of D-fructose on the SnO2/Al2O3 catalyst. The SnO2/Al2O3 catalyst was found to be stable for 6 h while maintaining full fruc-tose conversion at 55–70% methyl lactate selectivity. After regeneration the catalyst completely restores the initial activity.

Investigation of Some Characterizations of Black TiO\(_2\) Nanotubes Via Spectroscopic Methods

2019 ◽  
Vol 29 (2) ◽  
pp. 189 ◽  
Author(s):  
Tho Truong Nguyen ◽  
Thi Minh Cao ◽  
Hieu Van Le ◽  
Viet Van Pham
Keyword(s):  
Water Splitting ◽  
Oxygen Vacancies ◽  
Light Response ◽  
Nanotube Arrays ◽  
Spectroscopic Methods ◽  
Visible Light Response ◽  
Uv Visible ◽  
Visible Reflectance ◽  
Splitting Effect ◽  
Anodization Method

The black TiO\(_2\) with substantial Ti\(^3+\) and oxygen vacancies exhibit an excellent photoelectrochemical water-splitting performance due to the improved charge transport the extended visible light response. In this study, black TiO\(_2\) nanotube arrays synthesized by the anodization method, and then, they have been investigated some characterizations by spectroscopic methods such as UV-visible reflectance (UV-vis DRS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and photoluminescence spectrum. The results showed that some highlighted properties of the black TiO2 nanotube arrays and they could apply for water-splitting effect.

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