Synthesis, Characterization and Catalytic Properties of La4BaCu5-xNixO13+δ (x=0, 1, 2, 3, 4, 5)

2009 ◽  
Vol 66 ◽  
pp. 57-60 ◽  
Author(s):  
Xue Hui Huang ◽  
Hao Chen ◽  
Ting Ting Wu
Keyword(s):  
Catalytic Activity ◽  
Catalytic Properties ◽  
Defect Structures ◽  
Ch4 Oxidation ◽  
Citrate Method ◽  
Catalytic Activities

A series of perovskite-like catalusts La4BaCu5-xNixO13＋δ (x=0,1,2,3,4,5) were prepared by the citrate method, the structures, forms, properties, and defect structures were studied by means of XRD, SEM, BET and TPD measurements. Meanwhile, their catalytic activities were evaluated by the studying of CO, CH4 oxidation. La4BaCu2Ni3O13+δ shows the highest catalytic activity.

Controllable synthesis of Ni nanotube arrays and their structure-dependent catalytic activity toward dye degradation

CrystEngComm ◽  
2014 ◽  
Vol 16 (21) ◽  
pp. 4406-4413 ◽  
Author(s):  
Xiang-Zi Li ◽  
Kong-Lin Wu ◽  
Yin Ye ◽  
Xian-Wen Wei
Keyword(s):  
Catalytic Activity ◽  
Catalytic Properties ◽  
Dye Degradation ◽  
Nanotube Arrays ◽  
Nanorod Arrays ◽  
Growth Mechanisms ◽  
Controllable Synthesis ◽  
Catalytic Activities ◽  
One Step ◽  
The Relationship

Ni nanotube (nanorod) arrays are controllably fabricated by a one-step approach, the GDDATG and DDCG growth mechanisms are introduced. The Ni nanostructures present higher catalytic activities for dye degradation, the relationship between structures and catalytic properties is also studied.

FEATURES AND CATALYTIC PROPERTIES OF RhCu: A REVIEW

2010 ◽  
Vol 24 (25n26) ◽  
pp. 5128-5138 ◽  
Author(s):  
SILVIA GONZALEZ ◽  
CARMEN SOUSA ◽  
FRANCESC ILLAS
Keyword(s):  
Catalytic Activity ◽  
Bimetallic Catalysts ◽  
Catalytic Properties ◽  
Catalytic Activities ◽  
Cu Content ◽  
Bimetallic System

The study of bimetallic catalysts has scientific and technologic importance because of special catalytic activity towards several reactions. RhCu is an interesting bimetallic system due to combination of the very different catalytic activities of Rh and Cu. The catalytic activity of this bimetallic does not result from simple interpolation of the constituents. In fact, at low Cu content, the catalytic activity of RhCu is superior to that of Rh but when the Cu content is higher the activity decays. This is a curious trend which theoretical works had attempted to explain. This paper reports an overview of the most recent research works about this bimetallic system with emphasis in its especial characteristics.

scholarly journals Effect of Na2O Doping on the Surface and Catalytic Properties of the Mn2O3/Al2O3 System

1995 ◽  
Vol 12 (2) ◽  
pp. 119-128 ◽  
Author(s):  
G.A. El-Shobaky ◽  
A.M. Ghozza ◽  
S. Hammad
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Catalytic Properties ◽  
Xrd Analysis ◽  
Manganese Carbonate ◽  
Oxidation Of Co ◽  
Mechanical Mixing ◽  
Catalytic Activities ◽  
Specific Catalytic Activity ◽  
Catalytically Active

Manganese/aluminium mixed oxide solids having the formula 0.2MnCO3/Al2O3 were prepared by mechanical mixing of a known weight of finely powdered manganese carbonate and aluminium hydroxide. The solids obtained were treated with NaNO3 (0.75–6 mol%) solution and dried at 110°C, then calcined in air at 500°C and 800°C for 6 h. The phases produced were identified by XRD analysis. The surface properties (SBET, Vp and r̄) of the pure and doped solids were studied by using N2 adsorption at – 196°C and their catalytic activities were determined by studying the oxidation of CO by O2at 125–300°C. The results obtained reveal that pure and doped mixed solids preheated in air at 500°C and 800°C consist of Mn2O3 (partridgite) and a poorly crystalline γ-alumina. Doping with sodium oxide at 500°C and 800°C resulted in a small decrease (14–19%) in the SBET value of the treated solids. However, this treatment brought about a significant modification in the catalytic activity of the doped solids. Doping with 0.75% Na2O at 500°C led to an increase of about 30–50% in the specific catalytic activity which was found to decrease on increasing the percentage of Na2O above this limit, falling to values smaller than that measured for the undoped catalyst. Doping at 800°C led to a progressive decrease in the activity of the treated solid to an extent proportional to the amount of dopant present. The doping process at 500°C and 800°C did not modify the mechanism of the catalytic reaction but altered the number of catalytically-active sites contributing in the catalysis of CO oxidation by O2 without changing their energetic nature.

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.

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.

Effect of Templates on Catalytic Activity of Ordered Mesoporous Ceria for CO Oxidation

2014 ◽  
Vol 1033-1034 ◽  
pp. 95-98
Author(s):  
Peng Yang ◽  
Shi Yu Zhou ◽  
Jia Heng Lei
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Mesoporous Carbon ◽  
Catalytic Properties ◽  
X Ray ◽  
Catalytic Activities ◽  
Ordered Mesoporous ◽  
Ceria Catalysts ◽  
Fluorescence Spectrometer ◽  
The Relationship

Mesoporous ceria catalysts were prepared by nanocasting of a mesoporous carbon and KIT-6. The prepared mesoporous ceria catalysts were used to catalyze CO oxidation. The various characterization techniques were employed to study the relationship between catalyst nature and catalytic properties. The results indicate that ceria prepared by using mesoporous carbon as template possess an ordered mesoporous architecture and exhibit much better catalytic activity compared with those prepared by using KIT-6 as template. The residual SiO2from KIT-6 was demonstrated to be the main reason for the much worse catalytic activities by the characterization results of X-ray Fluorescence Spectrometer and FTIR spectra.

Decomposition of hydrogen peroxide on a two-component NiO-CdO catalyst and the effect of ionizing radiation on its catalytic properties

1979 ◽  
Vol 44 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
Viliam Múčka
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Nickel Oxide ◽  
Catalytic Properties ◽  
Cadmium Oxide ◽  
Chemisorb Oxygen ◽  
Composition Region ◽  
Chemisorbed Oxygen ◽  
Two Component

The catalytic properties of two-component catalyst nickel oxide-cadmium oxide with the proportions of the components covering the whole composition region 0-100% were examined by studying the decomposition of hydrogen peroxide in aqueous solution on it. In the range 0-25 mol.% CdO, cadmium oxide is found to affect infavourably the ability of nickel oxide to chemisorb oxygen. The amount of the chemisorbed oxygen increases several times on gamma irradiation of the samples. The effect of cadmium oxide on the catalytic activity of the system shows up in fresh samples only indirectly via the changed amount of the oxygen chemisorbed. In older samples the initial catalytic activity of the system is changed, which can be explained based on the concept of bivalent catalytic centres in terms of the co-action of the catalytic centres of the two oxides, which are in equilibrium. The irradiation of the system under study speeds up the processes leading to the establishing of this equilibrium which is thermally very stable, and results in a substantial increase of the catalytic activity of the samples investigated.

Hydrogen peroxide decomposition on a two-component CuO-Cr2O3 catalyst

1988 ◽  
Vol 53 (8) ◽  
pp. 1636-1646 ◽  
Author(s):  
Viliam Múčka ◽  
Kamil Lang
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Extreme Values ◽  
Catalytic Properties ◽  
Active Components ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Peroxide Decomposition ◽  
Two Component ◽  
Catalytically Active

Some physical and catalytic properties of the two-component copper(II)oxide-chromium(III)oxide catalyst with different content of both components were studied using the decomposition of the aqueous solution of hydrogen peroxide as a testing reaction. It has been found that along to both basic components, the system under study contains also the spinel structure CuCr2O4, chromate washable by water and hexavalent ions of chromium unwashable by water. The soluble chromate is catalytically active. During the first period of the reaction the equilibrium is being established in both homogeneous and heterogeneous catalytic systems. The catalytic activity as well as the specific surface area of the washed solid is a non-monotonous function of its composition. It seems highly probable that the extreme values of both these quantities are not connected with the detected admixtures in the catalytic system. The system under study is very insensitive with regard to the applied doses of gamma radiation. Its catalytic properties are changed rather significantly after the thermal treatment and particularly after the partial reduction to low degree by hydrogen. The observed changes of the catalytic activity of the system under study are very probably in connection with the changes of the valence state of the catalytically active components of the catalyst.

scholarly journals Influence of the Reduction Temperature and the Nature of the Support on the Performance of Zirconia and Alumina-Supported Pt Catalysts for n-Dodecane Hydroisomerization

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 88
Author(s):  
Diana García-Pérez ◽  
Maria Consuelo Alvarez-Galvan ◽  
Jose M. Campos-Martin ◽  
Jose L. G. Fierro
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Catalytic Properties ◽  
Catalytic Performance ◽  
Major Influence ◽  
Pt Catalysts ◽  
Reduction Temperature ◽  
Metal Dispersion ◽  
Tungsten Oxides ◽  
Supported Pt Catalysts

Catalysts based on zirconia- and alumina-supported tungsten oxides (15 wt % W) with a small loading of platinum (0.3 wt % Pt) were selected to study the influence of the reduction temperature and the nature of the support on the hydroisomerization of n-dodecane. The reduction temperature has a major influence on metal dispersion, which impacts the catalytic activity. In addition, alumina and zirconia supports show different catalytic properties (mainly acid site strength and surface area), which play an important role in the conversion. The NH3-TPD profiles indicate that the acidity in alumina-based catalysts is clearly higher than that in their zirconia counterparts; this acidity can be attributed to a stronger interaction of the WOx species with alumina. The PtW/Al catalyst was found to exhibit the best catalytic performance for the hydroisomerization of n-dodecane based on its higher acidity, which was ascribed to its larger surface area relative to that of its zirconia counterparts. The selectivity for different hydrocarbons (C7–10, C11 and i-C12) was very similar for all the catalysts studied, with branched C12 hydrocarbons being the main products obtained (~80%). The temperature of 350 °C was clearly the best reduction temperature for all the catalysts studied in a trickled-bed-mode reactor.

scholarly journals Development of palladium catalysts modified by ruthenium and molybdenum as anode in direct ethanol fuel cell

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yonis Fornazier Filho ◽  
Ana Caroliny Carvalho da Cruz ◽  
Rolando Pedicini ◽  
José Ricardo Cezar Salgado ◽  
Priscilla Paiva Luz ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Catalysts ◽  
Carbon Support ◽  
X Ray Diffraction ◽  
Direct Ethanol Fuel Cell ◽  
Pd Catalysts ◽  
Bifunctional Mechanism ◽  
Catalytic Activities ◽  
Intrinsic Mechanism ◽  
Ternary Catalysts

AbstractPhysical and electrochemical properties of Pd catalysts combined with Ru and Mo on carbon support were investigated. To this end, Pd, Pd1.3Ru1.0, Pd3.2Ru1.3Mo1.0 and Pd1.5Ru0.8Mo1.0 were synthesized on Carbon Vulcan XC72 support by the method of thermal decomposition of polymeric precursors and then physically and electrochemically characterized. The highest reaction yields are obtained for Pd3.2Ru1.3Mo1.0/C and Pd1.5Ru0.8Mo1.0/C and, as demonstrated by thermal analysis, they also show the smallest metal/carbon ratio compared the other catalysts. XRD (X-ray Diffraction) and Raman analyses show the presence of PdO and RuO2 for the Pd/C and the Pd1.3Ru1.0/C catalysts, respectively, a fact not observed for the Pd3.2Ru1.3 Mo1.0 /C and the Pd1.5Ru0.8Mo1.0/C catalysts. The catalytic activities were tested for the ethanol oxidation in alkaline medium. Cyclic voltammetry (CV) shows Pd1.3Ru1.0/C exhibiting the highest peak of current density, followed by Pd3.2Ru1.3Mo1.0/C, Pd1.5Ru0.8Mo1.0/C and Pd/C. From, chronoamperometry (CA), it is possible to observe the lowest rate of poisoning for the Pd1.3Ru1.0/C, followed by Pd3.2Ru1.3Mo1.0/C, Pd1.5Ru0.8Mo1.0/C and Pd/C. These results suggested that catalytic activity of the binary and the ternary catalysts are improved in comparison with Pd/C. The presence of RuO2 activated the bifunctional mechanism and improved the catalytic activity in the Pd1.3Ru1.0/C catalyst. The addition of Mo in the catalysts enhanced the catalytic activity by the intrinsic mechanism, suggesting a synergistic effect between metals. In summary, we suggest that it is possible to synthesize ternary PdRuMo catalysts supported on Carbon Vulcan XC72, resulting in materials with lower poisoning rates and lower costs than Pd/C. Graphic abstract

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