scholarly journals Influence of Structure on Catalytic Properties of La0.7Sr0.3BO3 (B = Mn, Fe, Ni) Perovskite Catalysts in Total Oxidation Reaction of M-Xylene 

2021 ◽  
Vol 31 (3) ◽  
pp. 31-36
Keyword(s):  
Catalytic Activity ◽  
Structural Properties ◽  
Oxidation Reaction ◽  
Catalytic Properties ◽  
Sol Gel ◽  
Diffraction Method ◽  
Nitrogen Adsorption ◽  
Structural Features ◽  
Total Oxidation ◽  
Perovskite Catalysts

In this study, the influence of structure on catalytic properties of La0.7Sr0.3BO3 (B = Mn, Fe, Ni) perovskite catalysts in total oxidation reaction of m-xylene was studied. Perovskite oxides of La0.7Sr0.3BO3 (B = Mn, Fe, Ni) were prepared by sol-gel citrate method. Structural properties of these materials were determined by various physico-chemical methods such as X-ray diffraction method (XRD) with Rietveld analytical method using Fullprof program, infra - red spectroscopy method (IR), temperature - programmed desorption of oxygen (TPDO) method and nitrogen adsorption and desorption isotherms method (BET). Obtained results show that there is a close relationship between the structural properties and catalytic activity of these materials: the catalyst that has the more of structural distortion, the larger of specific surface area, the greater of the amount of chemically adsorbed oxygen on the catalyst and the less durable of B-O link that has the higher of catalytic activity in total oxidation recation of m-xylene. Perovskite of La0.7Sr0.3MnO3 has structural features the best, so it has the highest of catalytic activity in total oxidation recation of m-xylene.

scholarly journals The Study on the Reaction Order and Kinetics of Total Oxidation Reaction of m-xylene over LaMnO3 Perovskite Catalyst

2018 ◽  
Vol 34 (3) ◽  
Author(s):  
Tran Thi Thu Huyen ◽  
Dang Thi Minh Hue ◽  
Nguyen Thi Tuyet Mai ◽  
Tran Thi Luyen ◽  
Nguyen Thi Lan
Keyword(s):  
Catalytic Activity ◽  
Reaction Order ◽  
Catalytic Properties ◽  
Sol Gel ◽  
Deep Oxidation ◽  
Perovskite Oxide ◽  
Mixed Metal Oxide ◽  
Total Oxidation ◽  
Kinetics Of ◽  
Perovskite Type

Gases of m-xylene is one of the popurlar toxic pollutants in the exhaust gases, it is emitted into the environment from factories and engines because the fuel in the engine does not burn completely. The best solution in order to remove this toxic gases of m-xylene to protect the environment is transforming them completely into CO2 and H2O by catalysts. Perovskite of LaMnO3 is one of the catalysts that was synthesized and studied the catalytic properties in total oxidation of m-xylene in our previous report. Obtained results showed that the LaMnO3 perovskite has good catalytic characterizations such as large surface area and the amount of α-oxygen adsorbed on the catalyst is large too. So, it exhibits a good catalytic activity in total oxidation of m-xylene at relatively low reaction temperature. In present work, the reaction order  and kinetics of this reaction are determined. The obtained results demonstrated that the reaction order value with respect to m-xylene is equal to about 1, to oxygene is proximately equal to 0 and the order of reaction is equal to about 1. Based on reaction order data, it was thought that the pathway of m-xylene oxidation by air oxygen  over LaMnO3 may be followed through which the Langmuir - Hinshelwood mechanism. Keywords Catalyst, perovskite, oxidation, m-xylene, kinetics References [1] Penã M.A and Fierro J.L.G (2001), << Chemical Stuctures and Performance of Perovskite Oxide>>, Chem. Rev, 101, pp 1981-2018. [2] Seiyama T., Yamazoe N. and Eguchi K. (1985), <<Characterization and Activity of some Mixed Metal Oxide Catalysts>>, Ind. Eng. Chem. Prod. Res. Dev., 24, pp. 19-27.[3] [3] Van Santen R. A., Neurock M. (2006), Molecular Heterogeneous catalysis, Wiley – VCH, pp.62-244. [4] Petrovics, Terlecki - Baricevic A., Karanovic Lj., Kirilov - Stefanov P. , Zdujic M., Dondur V., Paneva D., Mitov I., Rakic V. (2008), <<LaMO3 (M = Mg, Ti, Fe) perovskite type oxides : Preparation, Characterization and Catalytic Properties in Methane deep Oxidation>>, Appl. Catal. B, Env., 79, pp. 186-198. [5] Spinicci R., Tofanari A., Faticanti M., Pettiti I. and Porta P. (2001), <<Hexane Total Oxidation on LaMO3 (M = Mn, Co, Fe) perovskite-type oxides>>, J. Mole. Catal., 176, pp. 247-252. [6] Trần Thị Thu Huyền, Nguyễn Thị Minh Hiền, Nguyễn Hữu Phú (2006), <<Study on the preparation of perovskite oxides La1-xSrxMnO3 (x = 0; 0,3; 0,5) by sol - gel citrate method and their catalytic activity for m-xylene toltal oxidation>>, Hội nghị xúc tác và hấp phụ toàn quốc lần thứ IV, Tp. Hồ Chí Minh, Tr. 477-482.[7] Trần Thị Thu Huyền, Nguyễn Thị Minh Hiền, Nguyễn Hữu Phú (2009), <<Nghiên cứu động học của phản ứng oxi hóa hoàn toàn m-xylen trên các xúc tác perovskit LaMnO3 và La0,7A0,3MnO3 (A = Sr, Ca, Mg)>>, Tạp chí Hóa học, T.47 (6A), Tr 132-136.[8] Geoffrey C. Bond, Catherine Louis, David T. Thompson (2006), <<Catalysis by Gold>>, Catalytic Science Series-Vol.6.

scholarly journals The Determing Activation Energy of Total Oxidation Reaction of m-xylene over La0,7Sr0,3BO3 (B = Mn, Fe, Ni) Perovskite Catalysts

2017 ◽  
Vol 33 (4) ◽  
Author(s):  
Tran Thi Thu Huyen ◽  
Tran Thi Luyen ◽  
Nguyen Thi Tuyet Mai
Keyword(s):  
Activation Energy ◽  
Catalytic Activity ◽  
Oxidation Reaction ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Rare Earth Ions ◽  
Exhaust Emission ◽  
Total Oxidation ◽  
Low Reaction Temperature ◽  
Good Catalytic Activity

Perovskite-type oxides containing rare earth ions and transition metals are of interest for catalytic oxidation and reduction reactions associated with automotive exhaust emission control. They are known to exhibit a good catalytic activity in the total oxidation reaction of carbon monoxide or hydrocarbon and removal of nitrogen oxides. By partially substitution of A and B ions of the perovskite with others, a wide variety of mixed oxides A1-xA’xB1-yB’yO3 can be obtained, allowing the systematic modification of the catalytic properties. We presented the preparation and the catalytic properties of and La0.7Sr0.3BO3 (B = Mn, Fe, Ni) perovskites in total oxidation of m-xylene in previous report. Obtained results showed that they exhibit a good catalytic activity in total oxidation of  m-xylene at relatively low reaction temperature. In present work, the activation energy of total oxidation reaction of m-xylene over these catalysts are determined. The results show that the activation energy of studied catalyst is ranging about from 11.5 to 13.4 kcal/mol. The replacement of Mn by Fe and Ni in La0.7Sr0.3MnO3  perovskite catalyst reduces the catalytic property of  La0.7Sr0.3MnO3 catalyst and increases the activation energy of the total oxidation reaction of m-xylene. 

Study of Structural and Catalytic Properties of Pt/WOх/ZrO₂, Modified by Lanthanum Cations

2020 ◽  
pp. 133-141
Author(s):  
Svetlana A. Naumova ◽  
Anastasia V. Obukhova ◽  
Ludmila I. Kuznetsova
Keyword(s):  
Solid Solution ◽  
Catalytic Activity ◽  
Phase Composition ◽  
Structural Properties ◽  
Catalytic Properties ◽  
Surface Layers ◽  
Tetragonal Modification ◽  
Nanocrystalline Zirconia ◽  
Positive Effect

The effect of the addition of La3+ cations on the structural properties of Pt/WOх/ZrO₂ catalysts and the characteristics of catalytic activity in the process of hydroisomerization of n-heptane and benzene mixture was studied. The phase composition of the catalysts is represented by a solid solution of lanthanum cations in nanocrystalline zirconia of tetragonal modification with localization of lanthanum in the surface layers predominantly. The positive effect of La3+ additives on the selectivity and yield of isomerized products was shown

Investigation of ZnO/CuO/Nanographene Platelets Composites Catalyst for the Degradation of Methylene Blue from Aqueous Solution

2016 ◽  
Vol 864 ◽  
pp. 117-122 ◽  
Author(s):  
Hesni Shabrany ◽  
Hendry Tju ◽  
Ardiansyah Taufik ◽  
Rosari Saleh
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Catalytic Activity ◽  
Visible Light ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Ultrasound Irradiation ◽  
X Ray Diffraction ◽  
X Ray

This paper discusses the catalytic activity of ZnO/CuO/nanographene platelets composites under visible light and ultrasound irradiation separately. The ZnO/CuO/nanographene platelets composites were synthesized using a sol-gel method. X-ray diffraction and nitrogen adsorption spectroscopy were employed to investigate the structural and surface area of the catalyst. The catalytic activity results showed that the presence of nanographene platelets in ZnO/CuO nanocomposites improved its efficiency in degrading methylene blue. A scavenger method was also used to understand the role of charged carriers and the active radical involved in the catalytic activity.

Article

1998 ◽  
Vol 76 (4) ◽  
pp. 382-388 ◽  
Author(s):  
Jack M Miller ◽  
David Wails ◽  
J Stephen Hartman ◽  
Karla Schebesh ◽  
Jennifer L Belelie
Keyword(s):  
Catalytic Activity ◽  
Pore Size ◽  
Zinc Chloride ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Potassium Fluoride ◽  
Physical Structure ◽  
Alkylation Reaction ◽  
Size Distributions ◽  
Pore Size Distributions

Novel mesoporous silicas have been prepared via a sol-gel route involving fluoride-catalyzed hydrolysis of tetraethylorthosilicate (TEOS). Incorporation of zinc chloride by sol-gel synthesis gives a range of mesoporous materials with significantly higher catalytic activity than the commercially available catalyst, Clayzic, in a model Friedel-Crafts alkylation reaction. The dependence of catalytic activity and physical structure on the amounts of solvent, water, zinc chloride, and potassium fluoride used in the preparation are explored, and the materials have been further characterized by nitrogen adsorption to determine surface areas, total pore volumes, and pore-size distributions and by 29Si and 19F MAS NMR spectroscopy. The most active catalysts generally have the highest total pore volumes, with pore-size distributions larger than 8 nm.Key words: sol-gel, Friedel-Crafts, Clayzic, silica.

scholarly journals Ni–Cu High-Loaded Sol–Gel Catalysts for Dehydrogenation of Liquid Organic Hydrides: Insights into Structural Features and Relationship with Catalytic Activity

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2017
Author(s):  
Yuliya Gulyaeva ◽  
Maria Alekseeva (Bykova) ◽  
Olga Bulavchenko ◽  
Anna Kremneva ◽  
Andrey Saraev ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Sol Gel ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Structural Features ◽  
Atomic Ratio ◽  
Fixed Bed Reactor ◽  
High Catalytic Activity ◽  
Wide Range ◽  
Structure Reactivity Relationship

The heightened interest in liquid organic hydrogen carriers encourages the development of catalysts suitable for multicycle use. To ensure high catalytic activity and selectivity, the structure–reactivity relationship must be extensively investigated. In this study, high-loaded Ni–Cu catalysts were considered for the dehydrogenation of methylcyclohexane. The highest conversion of 85% and toluene selectivity of 70% were achieved at 325 °C in a fixed-bed reactor using a catalyst with a Cu/Ni atomic ratio of 0.23. To shed light on the relationship between the structural features and catalytic performance, the catalysts were thoroughly studied using a wide range of advanced physicochemical tools. The activity and selectivity of the proposed catalysts are related to the uniformity of Cu distribution and its interaction with Ni via the formation of metallic solid solutions. The method of introduction of copper in the catalyst plays a crucial role in the effectiveness of the interaction between the two metals.

Facile surface improvement method for LaCoO3 for toluene oxidation

2018 ◽  
Vol 8 (12) ◽  
pp. 3166-3173 ◽  
Author(s):  
Qilei Yang ◽  
Dong Wang ◽  
Chizhong Wang ◽  
Xianfeng Li ◽  
Kezhi Li ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Catalytic Activity ◽  
Sol Gel ◽  
Toluene Oxidation ◽  
Gel Method ◽  
Sol Gel Method ◽  
Improvement Method ◽  
Perovskite Catalysts ◽  
Surface Improvement

LaCoO3 (LCO-0) perovskite catalysts were synthesized by the traditional citrate sol-gel method for toluene oxidation. The catalytic activity of the modified LaCoO3 (LCO-1) by acetic acid significantly increased.

CO Catalytic Oxidation Performances of Pd-Doped BaCeO3

2020 ◽  
Vol 12 (11) ◽  
pp. 1293-1300
Author(s):  
Xihan Tan ◽  
Ying Li ◽  
Pengpeng Wu
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Crystal Size ◽  
Catalytic Properties ◽  
Sol Gel ◽  
Co Catalytic Oxidation ◽  
Pd Doping ◽  
Catalyst Powder ◽  
Doping Ratio ◽  
Oxidation Of Carbon Monoxide

A series of palladium doped barium-based cerium (BaCe1-xPdxO3-δ) catalysts were prepared by the sol–gel method. The catalytic properties of BaCe1-xPdxO3-δ for the oxidation of carbon monoxide were studied. The results show that Pd doping can effectively inhibit the crystal size of catalyst powder, and the specific surface area of the catalyst increases with the increase of doping ratio. Palladium doping significantly improved the catalytic activity of barium ceric acid-based catalyst for CO oxidation. BaCe0.96Pd0.04O3-δ had the best catalytic activity for CO oxidation. After calcination at high temperature, the BaCeO3 perovskite is stable.

Preparation, Characterization and Catalytic Properties of Nanostructured Mesoporous Au/CeO2

2015 ◽  
Vol 778 ◽  
pp. 144-147
Author(s):  
Si Qin Deligen ◽  
Bao Agula
Keyword(s):  
Catalytic Activity ◽  
Reduction Method ◽  
Catalytic Properties ◽  
Chemical Reduction ◽  
Nanoparticle Assembly ◽  
Complete Oxidation ◽  
Chemical Reduction Method ◽  
Total Oxidation ◽  
Catalytic Activities ◽  
Surfactant Assisted

The mesoporous CeO2were prepared via a surfactant-assisted method of nanoparticle assembly, CTAB was used as surfactant. The mesoporous CeO2were used as the supports for preparingxAu/CeO2catalysts by the chemical reduction method, and the catalytic activities of the total oxidation of propane were studied. The prepared catalysts were characterized by XRD, TEM and N2adsorption techniques. The content of Au can affect the catalytic properties of thexAu/CeO2catalysts. 4Au/CeO2exhibited the highest catalytic activity in propane complete oxidation with theT100of 420 °C.

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