Oxidative ammonolysis of methylpyrazine over binary catalytic systems: III. Phosphorus-molybdenum system: Catalytic properties and the active component

2000 ◽  
Vol 41 (2) ◽  
pp. 222-230 ◽  
Author(s):  
V. M. Bondareva ◽  
T. V. Andrushkevich ◽  
N. N. Chumachenko ◽  
R. I. Maksimovskaya ◽  
L. M. Plyasova ◽  
...  
Keyword(s):  
Active Component ◽  
Catalytic Properties ◽  
Catalytic Systems ◽  
Oxidative Ammonolysis

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.

Isomorphous rare-earth tris[bis(2,6-diisopropylphenyl) phosphate] complexes and their catalytic properties in 1,3-diene polymerization and in the inhibited oxidation of polydimethylsiloxane

2018 ◽  
Vol 74 (5) ◽  
pp. 590-598 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Alexander N. Tavtorkin ◽  
Sof'ya A. Korchagina ◽  
Galina N. Bondarenko ◽  
Andrei V. Churakov ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Catalytic Properties ◽  
Molar Ratio ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Neodymium Complex ◽  
Butadiene Polymerization ◽  
Bond Network ◽  
Phosphate Ligands ◽  
Monodentate Coordination

Crystals of mononuclear tris[bis(2,6-diisopropylphenyl) phosphato-κO]pentakis(methanol-κO)lanthanide methanol monosolvates of lanthanum, [La(C24H34O4P)3(CH3OH)5]·CH3OH, (1), cerium, [Ce(C24H34O4P)3(CH3OH)5]·CH3OH, (2), and neodymium, [Nd(C24H34O4P)3(CH3OH)5]·CH3OH, (3), have been obtained by reactions between LnCl3(H2O) n (n = 6 or 7) and lithium bis(2,6-diisopropylphenyl) phosphate in a 1:3 molar ratio in methanol media. Compounds (1)–(3) crystallize in the monoclinic P21/c space group and have isomorphous crystal structures. All three bis(2,6-diisopropylphenyl) phosphate ligands display a κO-monodentate coordination mode. The coordination number of the metal atom is 8. Each [Ln{O2P(O-2,6-iPr2C6H3)2}3(CH3OH)5] molecular unit exhibits four intramolecular O—H...O hydrogen bonds, forming six-membered rings. The unit forms two intermolecular O—H...O hydrogen bonds with one noncoordinating methanol molecule. All six hydroxy H atoms are involved in hydrogen bonding within the [Ln{O2P(O-2,6-iPr2C6H3)2}3(CH3OH)5]·CH3OH unit. This, along with the high steric hindrance induced by the three bulky diaryl phosphate ligands, prevents the formation of a hydrogen-bond network. Complexes (1)–(3) exhibit disorder of two of the isopropyl groups of the phosphate ligands. The cerium compound (2) demonstrates an essential catalytic inhibition in the thermal decomposition of polydimethylsiloxane in air at 573 K. Catalytic systems based on the neodymium complex tris[bis(2,6-diisopropylphenyl) phosphato-κO]neodymium, (3′), which was obtained as a dry powder of (3) upon removal of methanol, display a high catalytic activity in isoprene and butadiene polymerization.

scholarly journals Metal-support interactions in the design of heterogeneous catalysts for redox processes

2019 ◽  
Vol 91 (4) ◽  
pp. 609-631 ◽  
Author(s):  
Ekaterina S. Lokteva ◽  
Elena V. Golubina
Keyword(s):  
Carbon Nanotubes ◽  
Functional Groups ◽  
Organic Molecules ◽  
Catalytic Properties ◽  
Support Surface ◽  
Carbon Supports ◽  
Catalytic Systems ◽  
Metal Support Interaction ◽  
Active Metal ◽  
Metal Support

Abstract The effect of the metal-support interaction (MSI) has been discussed for several types of catalytic systems comprising metal nanoparticles (Ni, Pd, Au, Fe) on oxide and carbon supports, showing promising catalytic properties in hydrogenation of unsaturated C–C bonds, hydrodechlorination (HDC) of chlorinated organic molecules and CO total oxidation. The MSI of a different strength, from the redistribution of the electron density of nanoparticles (NPs) to the chemical interactions, is determined by the composition of the support and the active site, the method of active metal deposition, calcination temperature, particle size etc. The types of MSI considered in this review include: (1) the interaction of the active metal (Me) NPs with alumina and modified zirconia to form several oxidation states of Me in the composition of surface or bulk chemical compounds with a support; (2) the influence of oxide (alumina, silica) or carbon (highly oriented pyrolytic graphite, Sibunit) supports on the formation of active sites in the catalysts with ultra-low Me loading prepared by deposition of pre-formed metal NPs produced by laser electrodispersion (LED) or as colloidal dispersion; (3) the anchoring of Me NPs on the surface of carbon supports (nanodiamonds and carbon nanotubes) directly with a support surface, e.g. through surface defects, or through surface functional groups; (4) ‘reverse’ MSI in the Me@C composites, consisting of metal NPs, covered with the defected graphene layers or immersed into carbon matrix. It is demonstrated on the example of LED systems, that oxidation of metal under MSI is less significant in carbon-supported systems than in oxide-supported ones, but charge effects can play a noticeable role for both types of supports. Different ways of MSI tuning provide the possibilities to achieve the optimal Men+/Me0 ratio in the catalysts for HDC of mono- and polychlorinated organic molecules, including persistent organic pollutants. One of these ways is tuning the composition of functional groups on the surface of nanodiamonds and carbon nanotubes by additional treatments to achieve the desirable metal anchoring, the optimal metal NPs size and the improved catalytic properties. Unusual type of MSI is represented by the activation of thin graphene shell of Me@C composites by the presence of defects in the shell and a transition metal (Ni, Fe) in subsurface layer. This effect allows H2 activation that is a significant step in many industrially important reactions. The selectivity and activity of such systems can be intentionally changed by varying the nature of metal and reaction temperature. Significant attention has been given in the review to the novel catalytic systems described in the previous works of the authors.

ChemInform Abstract: Catalytically Active Complexes and Influence of SiO2 on the Catalytic Properties of the Active Component of Vanadium Catalysts for SO2 Oxidation.

ChemInform ◽  
1987 ◽  
Vol 18 (17) ◽  
Author(s):  
V. M. MASTIKHIN ◽  
O. B. LAPINA ◽  
B. S. BALZHINIMAEV ◽  
L. G. SIMONOVA ◽  
L. M. KARNATOVSKAYA ◽  
...  
Keyword(s):  
Active Component ◽  
Catalytic Properties ◽  
So2 Oxidation ◽  
Vanadium Catalysts ◽  
Catalytically Active

Catalytic properties and phase composition of multicomponent catalysts for oxidative ammonolysis of propane

1982 ◽  
Vol 18 (1-2) ◽  
pp. 7-11 ◽  
Author(s):  
S. Yu. Burylin ◽  
Z. G. Osipova ◽  
V. D. Sokolovskii ◽  
I. P. Olenkova
Keyword(s):  
Phase Composition ◽  
Catalytic Properties ◽  
Oxidative Ammonolysis ◽  
Multicomponent Catalysts

Structure of the active component and catalytic properties of catalysts prepared by the reduction of layered nickel aluminosilicates

2006 ◽  
Vol 47 (3) ◽  
pp. 412-422 ◽  
Author(s):  
A. A. Khasin ◽  
T. M. Yur’eva ◽  
V. V. Kaichev ◽  
V. I. Zaikovskii ◽  
M. P. Demeshkina ◽  
...  
Keyword(s):  
Active Component ◽  
Catalytic Properties

Complex Catalysts for Direct Synthesis of Dimethyl Ether from Synthesis Gas. Part I: Study of the Catalytic Properties

2013 ◽  
Vol 872 ◽  
pp. 15-22 ◽  
Author(s):  
Natalia I. Kosova ◽  
Pavel Musich ◽  
Irina A. Kurzina ◽  
Alexander Vosmerikov
Keyword(s):  
Dimethyl Ether ◽  
Synthesis Gas ◽  
Catalytic Properties ◽  
Direct Synthesis ◽  
Zeolite Catalysts ◽  
Methanol Dehydration ◽  
Combined Process ◽  
Catalytic Systems ◽  
Synthesis Of Dimethyl Ether

The results of the development of combined process for production of dimethyl ether (CuO/ZnO/Al2O3) and methanol dehydration (γ-Al2O3, zeolite (ZSM-5 type) with a silicate modulus (М) 20, 30, 60, 80, 100, and 200) are presented. The experiments on the influence of the catalysts loading and catalytic conditions were carried out (Р=3 MPa, Н2/СО=2, Т=553 К). It was established that the use of ZSM-5 zeolite catalysts with silicate modulus of 30 allows obtaining the yield of dimethyl ether up to 39%. It was stated that catalytic systems were stable during 180 h.

scholarly journals Effect of structural defects in alumina supports on the formation and catalytic properties of the active component of reforming catalysts

2013 ◽  
Vol 110 (2) ◽  
pp. 459-470 ◽  
Author(s):  
Ella M. Moroz ◽  
Dmitriy A. Zyuzin ◽  
Valentina Yu. Tregubenko ◽  
Irina E. Udras ◽  
Alexander S. Belyi ◽  
...  
Keyword(s):  
Active Component ◽  
Catalytic Properties ◽  
Structural Defects ◽  
Reforming Catalysts ◽  
Alumina Supports
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