Structures and Catalytic Activities of LaSrCoO4 and LaSrCoO3.6F0.4 Mixed Oxides

2011 ◽  
Vol 55-57 ◽  
pp. 1957-1961
Author(s):  
Xiao Mao Yang
Keyword(s):  
Particle Size ◽  
Catalytic Activity ◽  
Oxygen Vacancies ◽  
Mixed Oxides ◽  
Lattice Oxygen ◽  
Gel Method ◽  
Catalytic Activities ◽  
Surface Areas ◽  
Better Than

The perovskite-like LaSrCoO4and LaSrCoO3.6F0.4mixed oxides were prepared by the polyglycol gel method, investigated by using the XRD, TEM, BET, O2-TPD and XPS methods, and used successfully for CO and C3H8oxidization. The results indicate that LaSrCoO4and LaSrCoO3.6F0.4mixed oxides have K2NiF4structure. The catalytic activity of LaSrCoO4is better than that of LaSrCoO3.6F0.4, this is explained in terms of more mobile lattice oxygen, higher content of Co3+, more oxygen vacancies, smaller particle size and larger BET surface areas of LaSrCoO4.

Controlled synthesis and enhanced photoelectro-catalytic activity of a 3D TiO2 nanotube array/TiO2 nanoparticle heterojunction using a combined dielectrophoresis/sol–gel method

2019 ◽  
Vol 7 (17) ◽  
pp. 4981-4987 ◽  
Author(s):  
Ruiyu Bao ◽  
Chen Chen ◽  
Jianxin Xia ◽  
Huiying Chen ◽  
Hua Li
Keyword(s):  
Particle Size ◽  
Catalytic Activity ◽  
Surface Morphology ◽  
Sol Gel ◽  
Tio2 Nanoparticle ◽  
Controlled Synthesis ◽  
Tio2 Nanotube Array ◽  
Nanotube Array ◽  
Gel Method ◽  
Sol Gel Method

The surface morphology and particle size of materials can be controlled using DEP technology.

CATALYTIC ACTIVITY FOR METHANE OXIDATION OF GOETHITE SUPPORTED ON ALUMINA

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4249-4254 ◽  
Author(s):  
KEI-ICHIRO MURAI ◽  
KOHEI TOMITA ◽  
SUGURU TOJO ◽  
TOSHIHIRO MORIGA ◽  
ICHIRO NAKABAYASHI
Keyword(s):  
Catalytic Activity ◽  
Specific Surface ◽  
Methane Oxidation ◽  
Model Experiment ◽  
The Other ◽  
Catalytic Activities ◽  
Surface Areas ◽  
Oxidation Of Methane ◽  
Other Hand ◽  
Specific Surface Areas

Two kinds of α- Fe 2 O 3 catalysts supported on χ- Al 2 O 3 and γ- Al 2 O 3 were synthesized. α- Fe 2 O 3 was prepared from α- FeOOH . As a model experiment, an investigation was made with the oxidation of methane. As all catalysts with various Fe contents supported on χ- Al 2 O 3 with various Fe contents had higher specific surface areas than those supported on γ- Al 2 O 3, α- Fe 2 O 3/χ- Al 2 O 3 catalyst has higher catalytic activities than α- Fe 2 O 3/γ- Al 2 O 3 catalyst. From SEM-EDS analyses, it is concluded that in α- Fe 2 O 3/χ- Al 2 O 3 catalyst, α- Fe 2 O 3 exists mainly on the surface of the support, because of flatness of the surface of χ- Al 2 O 3. On the other hand, in the case of α- Fe 2 O 3/γ- Al 2 O 3 catalyst, as the surface of support, γ- Al 2 O 3, is uneven, α- Fe 2 O 3 do not partially exist on the surface but in the pores.

Preparation of Cu/Co/Fe Mixed Oxides and their Catalytic Behavior on HC-SCR DeNOx

2014 ◽  
Vol 1033-1034 ◽  
pp. 1058-1062 ◽  
Author(s):  
Hong Bo Liu ◽  
Zhi Yong Huang ◽  
Lin Jie Li ◽  
Jun Ting Huang ◽  
Zhi Cong He ◽  
...  
Keyword(s):  
Mixed Oxides ◽  
Catalytic Reduction ◽  
Homogeneous Distribution ◽  
Catalytic Behavior ◽  
Reduction Of No ◽  
Catalytic Activities ◽  
Structure And Morphology ◽  
Surface Areas ◽  
Nox Conversion ◽  
Specific Surface Areas

Co/Cu/Fe mixed oxides (Co/Cu/Fe-MOs) were prepared by calcination of Cu/Co/Fe hydrotalcites (Co/Cu/Fe-HTs) precursors. Their structure and morphology were characterized by XRD, TGA, IR and SEM. Co/Cu/Fe-MOs were used for selective catalytic reduction of NO by hydrocarbon. Their catalytic activities were studied by NOx analyzer. The results show that Co/Cu/Fe-MOs have homogeneous distribution of hexagon with particles size around 30~50nm and the specific surface areas are around 70~110 m2∙g–1. Cu2Co8Fe5-MOs sample exhibits the highest NOx conversion of 32%. Co/Cu/Fe-MOs with lower calcination temperature have higher catalytic activities.

Effect of Different Silicate Supports on the Catalytic Performance of MoVTeO Mixed Oxides in Partial Oxidation of Isobutane

2014 ◽  
Vol 12 (1) ◽  
pp. 623-628
Author(s):  
Jing Hu ◽  
Zhifang Li ◽  
Xiaoyuan Yang ◽  
Wenli Ding ◽  
Jingqi Guan
Keyword(s):  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Partial Oxidation ◽  
Mixed Oxides ◽  
Supported Catalysts ◽  
Catalytic Performance ◽  
Surface Areas ◽  
Specific Surface Areas ◽  
Mcm 41

Abstract A series of 5% MoV0.3Te0.25 supported on different silicates (i.e. SiO2, HMS, MCM-41, and MCM-48) have been prepared, characterized, and tested as catalysts in the partial oxidation of isobutane to methacrolein. Characterization results showed that the supports almost kept intact structures after supporting 5 wt.% MoV0.3Te0.25 and the supported catalysts had large specific surface areas. Catalytic tests showed that the specific surface area played a key role in the catalytic activity for the supported catalysts.

scholarly journals Catalytic Combustion of Diesel Soot on Ce/Zr Series Catalysts Prepared by Sol-Gel Method

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 646 ◽  
Author(s):  
Chaoqian Ai ◽  
Yaoyao Zhang ◽  
Pan Wang ◽  
Wei Wang
Keyword(s):  
Solid Solution ◽  
Catalytic Activity ◽  
Ignition Temperature ◽  
Catalytic Combustion ◽  
Sol Gel ◽  
Diesel Soot ◽  
Lattice Oxygen ◽  
Gel Method ◽  
X Ray ◽  
Test Platform

Cerium-zirconium (Ce-Zr) solid solutions have been extensively used in a wide variety of catalytic processes due to their unique catalytic features in conjunction with lower cost compared to noble metal-based systems. A series of Ce-Zr-based catalysts was prepared by the sol-gel method. The structure and morphology of these catalysts were characterized by X-ray diffraction, thermogravimetric-differential scanning calorimetry, scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. Furthermore, investigation on catalytic performance was carried out by constructing a test platform, and the result indicated that the catalysts apparently decreased the soot ignition temperature. These catalysts exhibited higher catalytic activity for soot oxidation under narrow contact conditions. The results revealed that some soot particles could react with adsorbed oxygen, and other part of diesel soot reacted with lattice oxygen. The activity of these catalysts was attributed to synergistic effect arising from the combination of K/Co/Zr and Ce-Zr solid solution, which led to the decrease in the ignition temperature to 294 °C (data from the test platform). The catalyst still keeps good stability and catalytic activity after the cycle oxidation experiment. A reaction pathway was proposed to explain catalytic combustion process of soot, i.e., combination of K/Co/Zr with Ce-Zr solid solution reduced the binding energy of Ce-Zr solid solution, which was conducive to provide more active sites to release the active oxygen (O2−) or lattice oxygen (O2−).

Oxidation of carbon monoxide by oxygen over pure and platinum-doped LaMnO3 perovskites

1990 ◽  
Vol 55 (8) ◽  
pp. 1928-1934 ◽  
Author(s):  
Jaroslav Bartoň ◽  
Vladimír Pour
Keyword(s):  
Activation Energy ◽  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Apparent Activation Energy ◽  
Co Oxidation ◽  
Reaction Kinetics ◽  
Empirical Equation ◽  
Catalytic Activities ◽  
Surface Areas ◽  
Oxidation Of Carbon Monoxide

The properties of pure and platinum-doped LaMnO3 perovskites, including their catalytic activities for the reaction of CO with oxygen, have been determined. Perovskite samples were prepared by decomposition of lanthanum and manganese citrates. The surface areas were 12.2 m2/g for pure LaMnO3 and 9.8 m2/g for the platinum-doped sample. The doping with a small amount of platinum markedly enhances the catalytic activity of LaMnO3 perovskite. The (CO + O2) reaction starts at 200 °C over LaMnO3 and at temperatures below 100 °C over a sample doped with Pt. The reaction kinetics for both the pure and platinum-doped LaMnO3 can be described by empirical equation (4). When Pt-doped perovskite is used, an increase in the apparent activation energy occurs at about 150 °C. This fact is attributed to a change in the mechanism of CO oxidation.

scholarly journals Preparation of Ce–Mn Composite Oxides with Enhanced Catalytic Activity for Removal of Benzene through Oxalate Method

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 197 ◽  
Author(s):  
Min Yang ◽  
Genli Shen ◽  
Mi Liu ◽  
Yunfa Chen ◽  
Zhen Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Property ◽  
Catalytic Properties ◽  
Synergistic Interaction ◽  
Benzene Oxidation ◽  
Oxygen Species ◽  
Pure Ceo2 ◽  
Catalytic Activities ◽  
Composite Oxides ◽  
Better Than

The catalytic activities of CeO2-MnOx composite oxides synthesized through oxalate method were researched. The results exhibited that the catalytic properties of CeO2-MnOx composite oxides were higher than pure CeO2 or MnOx. When the Ceat/Mnat ratio was 3:7, the catalytic activity reached the best. In addition, the activities of CeO2-MnOx synthesized through different routes over benzene oxidation were also comparative researched. The result indicated that the catalytic property of sample prepared by oxalate method was better than others, which maybe closely related with their meso-structures. Meanwhile, the effects of synergistic interaction and oxygen species in the samples on the catalytic ability can’t be ignored.

Ambient temperature NO oxidation over Cr-based amorphous mixed oxide catalysts: effects from the second oxide components

2017 ◽  
Vol 7 (11) ◽  
pp. 2362-2370 ◽  
Author(s):  
Aiyong Wang ◽  
Bo Lin ◽  
Hanlei Zhang ◽  
Mark H. Engelhard ◽  
Yanglong Guo ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Specific Surface ◽  
Mixed Oxide ◽  
Mixed Oxides ◽  
Sol Gel ◽  
No Oxidation ◽  
Gel Method ◽  
Mixed Oxide Catalysts ◽  
Surface Areas ◽  
Specific Surface Areas

Three series of Cr-based mixed oxides (Cr–Co, Cr–Fe, and Cr–Ni oxides) with high specific surface areas and amorphous textures were synthesized using a novel sol–gel method.

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