Solid defect structure and catalytic activity of perovskite-type catalysts La1–xSrxNiO3–λand La1–1.333xThxNiO3–λ

1992 ◽  
Vol 88 (21) ◽  
pp. 3245-3249 ◽  
Author(s):  
Zuolong Yu ◽  
Lizhen Gao ◽  
Songyue Yuan ◽  
Yue Wu
Keyword(s):  
Catalytic Activity ◽  
Defect Structure ◽  
Perovskite Type

Electron Donating, Acid-Base and Catalytic Properties of Perovskite-Type Mixed Oxides of Rare Earths

1995 ◽  
Vol 60 (6) ◽  
pp. 977-982
Author(s):  
S. Sugunan ◽  
V. Meera
Keyword(s):  
Catalytic Activity ◽  
Electron Donor ◽  
Rare Earths ◽  
Electron Affinity ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Surface Acidity ◽  
Electron Acceptors ◽  
Acid Base ◽  
Perovskite Type

The electron donor properties of perovskite-type mixed oxides (LaFeO3, PrFeO3, SmFeO3, LaCoO3, PrCoO3, SmCoO3, LaNiO3, PrNiO3 and SmNiO3) were studied based on the adsorption of electron acceptors exhibiting different electron affinity viz. 7,7,8,8-tetracyanoquinodimethane, 2,3,5,6-tetrachloro-1,4-benzoquinone, p-dinitrobenzene, and m-dinitrobenzene. The surface acidity/basicity of the oxides was determined using a set of Hammett indicators. The data were correlated with the catalytic activity of the oxides for the reduction of cyclohexanone with 2-propanol.

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.

ChemInform Abstract: LaAl1-xCrxO3 Perovskite-Type Solid Solutions: Structural, Electronic, Magnetic Properties and Catalytic Activity Towards CO Oxidation.

ChemInform ◽  
2010 ◽  
Vol 33 (41) ◽  
pp. no-no
Author(s):  
Dante Cordischi ◽  
Sergio De Rossi ◽  
Marco Faticanti ◽  
Giuliano Minelli ◽  
Piero Porta
Keyword(s):  
Magnetic Properties ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Solid Solutions ◽  
Perovskite Type

The catalytic activity and defect structure of zinc chromate

1991 ◽  
Vol 8 (5-6) ◽  
pp. 385-389 ◽  
Author(s):  
R. A. Jackson ◽  
C. R. A. Catlow ◽  
J. M. Thomas
Keyword(s):  
Catalytic Activity ◽  
Defect Structure ◽  
Zinc Chromate

scholarly journals Lanthanum-Based Perovskite-Type Oxides La1−xCexBO3(B = Mn and Co) as Catalysts: Synthesis and Characterization

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Nyamdavaa Erdenee ◽  
Uyanga Enkhnaran ◽  
Sevjidsuren Galsan ◽  
Altantsog Pagvajav
Keyword(s):  
Catalytic Activity ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Reduction Behavior ◽  
Process Characterization ◽  
Lattice Geometry ◽  
Sol Gel Process ◽  
Ce Substitution ◽  
Crystallite Sizes ◽  
Perovskite Type

La1−xCexCoO3(x= 0, 0.2, 0.4) and La1−xCexMnO3(x= 0, 0.2) perovskite-type oxides were prepared by sol-gel process. Characterization techniques EDS, FTIR, XRD, BET, and XPS experiments were performed to survey the composition, bulk structure, and the surface properties of perovskites. The reduction behavior, thermal stability, and catalytic activity were studied by H2-TPR and catalytic performance. All synthesized samples showed well crystalline perovskite structure, 8–22 nm crystallite sizes, and SSA with 2–27 m2 g−1. The XRD results showed that the Ce substitution promoted the structural transformation for LaCoO3from rhombohedral into cubic and for LaMnO3no change in lattice geometry. Substitution with cerium (x= 0.2) showed smaller crystallite size, higher SSA, and the highest reducibility and catalytic activity for LaCoO3.

Point Defects and Protonic Conduction in A3B'B”2O9 Compounds

1994 ◽  
Vol 369 ◽  
Author(s):  
Yang Du ◽  
A.S. Nowick
Keyword(s):  
Electrical Conductivity ◽  
Ir Spectra ◽  
Point Defects ◽  
Defect Structure ◽  
Complex Perovskite ◽  
Divalent Ions ◽  
Protonic Conduction ◽  
Protonic Conductors ◽  
Lower Activation ◽  
Perovskite Type

AbstractWe have investigated the defect structure and protonic transport properties of nonstoichiometric complex perovskite-type compounds of the type A3B'1+xNb2-xO9-δ. where A and B' are both divalent ions. Protons are incorporated by treatment in H2O vapor and their presence is manifested by the appearance of an OH band in the IR spectra, as well as by the large increase in electrical conductivity to produce excellent protonic conductors, with lower activation energies. A non-classical isotope effect, in which the Arrhenius plots for D+ and H+ cross over, can be explained by a modification of the classical ART hopping theory.

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