Response in the catalytic properties to presulphidation for promoted and nonpromoted molybdenum hydrorefining catalysts

1984 ◽  
Vol 49 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Eva Hillerová ◽  
Rafael López ◽  
Jindřiška Maternová ◽  
Rudolf Peter ◽  
Miroslav Zdražil
Keyword(s):  
Catalytic Properties ◽  
Active Surface ◽  
Adsorption Properties ◽  
Published Data ◽  
Molybdenum Catalysts

The sensitivity of nonpromoted molybdenum catalysts to presulphidation was examined on the adsorption of hydrocarbons and pyridine, hydrodesulphurization of thiophene and benzothiophene, and cracking and dehydrogenation of isopropylbenezene. Published data of other authors concerning the hydrodesulphurization of thiophene and benzothiophene and hydrogenation of cyclohexene were also evaluated. In all cases except the dehydrogenation of isopropylbenzene, the change in the adsorption properties and catalysts activity brought about by the presulphidation were lower for the nonpromoted catalysts than for the promoted ones, thus indicating that cobalt is directly involved in the active surface of CoMo/Al2O3 catalysts.

Morphological, electronic and catalytic properties of silica-supported nickel and nickel-molybdenum catalysts

1984 ◽  
Vol 10 (1) ◽  
pp. 63-76 ◽  
Author(s):  
G. Kadinov ◽  
H. Praliaud ◽  
M. Primet ◽  
G.A. Martin
Keyword(s):  
Catalytic Properties ◽  
Molybdenum Catalysts

scholarly journals The Effect of the Method of Preparation on the Textural, Acidic and Catalytic Properties of Chromia–Alumina Catalysts

1996 ◽  
Vol 13 (5) ◽  
pp. 355-365
Author(s):  
Th. El-Nabarawy ◽  
L.B. Khalil ◽  
A. M. Youssef
Keyword(s):  
Water Vapour ◽  
Catalytic Properties ◽  
Acid Sites ◽  
Adsorption Properties ◽  
Pure Alumina ◽  
First Order ◽  
First Order Kinetics ◽  
Structure Sensitive ◽  
Adsorption Of Nitrogen ◽  
Alumina Catalysts

Pure alumina 'A' and chromia–alumina catalysts containing 25 mol% Cr2O3 (IAC, IIAC and IIIAC) were prepared by impregnation, coprecipitation and coating techniques, respectively. The adsorption of nitrogen at 77 K and of benzene and water vapour at 308 K was determined. The chemisorption of pyridine at 400 K was measured and the surface acidities calculated. The conversion of 2-propanol and cracking of cumene were investigated using the pulse microcatalytic technique. Coating alumina with chromia causes considerable changes in the textural and adsorption properties, impregnation of alumina with chromia leads to smaller variations while coprecipitation gives intermediate changes in textural and adsorption properties. The same was found true for the surface acidities as determined by the chemisorption of pyridine. The dehydration of 2-propanol and cracking of cumene follow first-order kinetics. The dehydration of propanol on alumina and chromia–alumina catalysts is a structure-insensitive reaction independent of the surface area but related to the surface acid density. The cracking of cumene is a structure-sensitive reaction depending on both the extent of the surface and the number of acid sites.

scholarly journals THE COMPARATIVE DESCRIPTION OF THE ADSORPTION PROPERTIES OF ENTEROSORBENTS

2016 ◽  
pp. 41-46
Author(s):  
V. A. Filippova ◽  
A. V. Lysenkova ◽  
V. A. Ignatenko ◽  
A. K. Dovnar
Keyword(s):  
Heavy Metals ◽  
Vitamin C ◽  
Adsorption Capacity ◽  
Active Surface ◽  
Adsorption Properties ◽  
Fourth Generation ◽  
High Adsorption ◽  
Toxic Heavy Metals ◽  
High Adsorption Capacity ◽  
Main Component

The aim of research: comparative study of adsorption capacity and selectivity of enterosorbents of different generations. Material and methods. The subject of the study is enterosorbents widely applied in clinical practice. They belong to different generations and exhibit different adsorption capacities and different doses of daily application. Results. It was found out that enterosorbents differed from one another and the latest generation had more perfect and diverse adsorption properties. The experimental data confirmed that enterosorbents of the fourth generation, in particular white carbon, whose main component is silicon dioxide exhibited a highly developed active surface and high adsorption capacity relative to highly toxic heavy metals, while its ability to bind and remove useful components (biometals and vitamin C) in organism was negligibly low. Conclusions. The enterosorbent of the fourth generation «White coal» possess high adsorption capacity toward heavy metals and simultaneously are characterized by negligibly low capacity to bind and remove bioactive compounds such as biometals and vitamin C.

scholarly journals A comparative analysis of platinum and oxide-based catalytic converters in terms of NOx reduction with ammonia

2012 ◽  
Vol 150 (3) ◽  
pp. 55-62
Author(s):  
Wojciech KAMELA ◽  
Stanisław KRUCZYŃSKI
Keyword(s):  
Comparative Analysis ◽  
Diesel Engine ◽  
Catalytic Properties ◽  
Nox Reduction ◽  
Active Surface ◽  
Catalytic Converters ◽  
Nitric Oxides ◽  
Exhaust Gases ◽  
Conversion Rates ◽  
Physical And Chemical

The paper presents a comparison of the catalytic properties of two types of catalytic converters (containing platinum and oxide active coatings) in the aspect of a reduction of nitric oxides with ammonia. The tests were performed for three concentrations of ammonia in the exhaust gases of a diesel engine. The work contains images of the topography of the active surface of the catalytic converters and the results of its physical and chemical analysis. The changes of the conversion rates of the nitric oxides have also been presented in the converter temperature range from 150 to 550 °C along with the results of calculations of the shares of NO2 in NOx for all analyzed concentrations of ammonia in the exhaust gases.

Hierarchical flowerlike magnesium oxide hollow spheres with extremely high surface area for adsorption and catalysis

2016 ◽  
Vol 4 (2) ◽  
pp. 400-406 ◽  
Author(s):  
Shuliang Yang ◽  
Peipei Huang ◽  
Li Peng ◽  
Changyan Cao ◽  
Yanan Zhu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Surface Area ◽  
Magnesium Oxide ◽  
Heavy Metal Ions ◽  
Catalytic Properties ◽  
Condensation Reaction ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Adsorption Properties

3D hierarchical flowerlike MgO hollow spheres with extremely high surface area showed excellent adsorption properties for heavy metal ions and catalytic properties for the Claisen–Schmidt condensation reaction.

Crystallographic identification of a series of manganese porphyrin complexes with nitrogenous bases

2019 ◽  
Vol 75 (3) ◽  
pp. 304-312
Author(s):  
Nicole Lahanas ◽  
Pavel Kucheryavy ◽  
Roger A. Lalancette ◽  
Jenny V. Lockard
Keyword(s):  
Biological Function ◽  
Catalytic Properties ◽  
Molecular Structures ◽  
Published Data ◽  
Manganese Porphyrin ◽  
Axial Ligation ◽  
Crystal And Molecular Structures ◽  
Axial Ligands ◽  
Iron Porphyrin Complexes ◽  
Mn Porphyrins

Studying the axial ligation behavior of metalloporphyrins with nitrogenous bases helps to better understand not only the biological function of heme-based protein systems, but also the catalytic properties of porphyrin-based reaction sites in other biomimetic synthetic support environments. Unlike iron porphyrin complexes, little is known about the axial ligation behavior of Mn porphyrins, particularly in the solid state with Mn in the +3 oxidation state. Here, we present the syntheses and crystal and molecular structures of three new high-spin manganese(III) porphyrin complexes with the different amine-based axial ligands imidazole (im), piperidine (pip), and 1,4-diazabicyclo[2.2.2]octane (DABCO), namely bis(imidazole)(5,10,15,20-tetraphenylporphyrinato)manganese(III) chloride chloroform disolvate, [Mn(C44H28N4)(C3H4N2)2]Cl·2CHCl3 or [Mn(TPP)(im)2]Cl·2CHCl3 (TPP = 5,10,15,20-tetraphenylporphyrin), (I), bis(piperidine)(5,10,15,20-tetraphenylporphyrinato)manganese(III) chloride, [Mn(C44H28N4)(C5H11N)2]Cl or [Mn(TPP)(pip)2]Cl, (II), and chlorido(1,4-diazabicyclo[2.2.2]octane)(5,10,15,20-tetraphenylporphyrin)manganese(III)–1,4-diazabicyclo[2.2.2]octane–toluene–water (4/4/4/1), [Mn(C44H28N4)Cl(C6H12N2)]·C6H12N2·C7H8·0.25H2O or [Mn(TPP)Cl(DABCO)]·(DABCO)·(toluene)·0.25H2O, (IV). A fourth complex, chlorido(pyridine)(5,10,15,20-tetraphenylporphryinato)manganese(III) pyridine disolvate, [Mn(C44H28N4)Cl(C5H5N)]·2C5H5N or [Mn(TPP)Cl(py)]·2(py), (III), acquired using different crystallization methods from published data, is also reported and compared to the previous structures.

Catalytic properties of silica-molybdenum catalysts in propylene oxidation

1980 ◽  
Vol 14 (1) ◽  
pp. 77-80 ◽  
Author(s):  
T. Kh. Shokhireva ◽  
T. M. Yurieva ◽  
N. N. Chumachenko
Keyword(s):  
Catalytic Properties ◽  
Propylene Oxidation ◽  
Molybdenum Catalysts
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