scholarly journals Solid-State Transformations in Inner Coordination Sphere of [Co(NH3)6][Fe(C2O4)3]∙3H2O as a Route to Access Catalytically Active Co-Fe Materials

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 221 ◽  
Author(s):  
Denis Domonov ◽  
Sophia Pechenyuk ◽  
Yulia Semushina ◽  
Kirill Yusenko
Keyword(s):  
Thermal Decomposition ◽  
Intermediate Phase ◽  
Catalytic Properties ◽  
Decomposition Reaction ◽  
Argon Atmosphere ◽  
Air Oxidation ◽  
Crystal Water ◽  
Highly Active ◽  
Catalytically Active ◽  
Average Activity

Thermal decomposition of [Co(NH3)6][Fe(C2O4)3]∙3H2O in argon atmosphere, at a low heating rate (3°/min), and in large amounts of the initial complex (~0.1 mole), has been studied. It was possible to distinguish four decomposition steps upon heating: In the temperature range of 50–100 °C—the loss of crystal water; 100–190 °C—stability region of dehydrated complex; 230–270 °C—the range of stability of intermediate phase with the formula CoFe(NH3)2(C2O4)2; 270–350 °C—thermal decomposition of the intermediate with the formation of metallic products and further air oxidation with the formation of Co1.5Fe1.5O4. Catalytic properties of thermolysis products were tested in the decomposition reaction of H2O2 (inactive), oxidation of acetone (average activity), and decomposition of ammonium perchlorate (highly active).

scholarly journals Associative and Dissociative Adsorption of N2O Molecule Over C24 Fullerene Doped With V, Mn, Ru, Pd and Rh: A DFT Investigation

2021 ◽  
Author(s):  
Meryem DERDARE ◽  
ABDELGHANI BOUDJAHEM
Keyword(s):  
Catalytic Properties ◽  
Decomposition Reaction ◽  
Dissociative Adsorption ◽  
Activation Energies ◽  
The Other ◽  
High Catalytic Activity ◽  
Metal Site ◽  
Au Clusters ◽  
Catalytically Active ◽  
Adsorption Energies

Abstract DFT calculations using the PBE-D3 level of theory were conducted on the C24 and MC23 (M = V, Mn, Ru, Pd, Rh and Au) clusters in order to determine their stability and electronic and magnetic properties. The interaction of the N2O molecule with the above clusters has also been examined in order to assess their adsorption and catalytic properties. The results show that the reactivity of the C24 fullerene was greatly improved after doping with a TM atom, and the metal atom which was replaced the carbon atom in the pure C24 fullerene is considered as the most favorable site to adsorb and dissociate the N2O molecule. The molecular adsorption of the N2O on the surface of the MC23 clusters from its oxygen atom was found to be less energetically favorable than by nitrogen atom, and the calculated adsorption energies (Eads) are in the range of - 6.5 to - 24.7 kcal mol-1. The N2O adsorption on the metal site of the clusters could also lead to the dissociation of the N2O into O* and N2 molecule with adsorption energies which vary from - 2.3 to - 86.8 kcal mol-1. The mechanism of the N2O dissociation on the clusters surface was studied, and the activation energies for each system were calculated in order to find the most catalytically active clusters in the N2O decomposition. The results indicate that the activation energies of the VC23 and MnC23 clusters are much lower than those obtained for the other clusters, reflecting high catalytic activity of the two clusters in the N2O decomposition reaction compared to the other studied clusters. The values of Eac of the reaction over the VC23 and MnC23 cluster are 9.3 and 7.9 kcal mol-1, respectively, indicating that both clusters could be employed as greatly active and efficient nanocatalysts for the N2O decomposition reaction.

Catalytically active coatings for steam reforming systems: synthesis and catalytic properties

2019 ◽  
pp. 96-105
Author(s):  
M. L. Shishkova ◽  
N. V. Yakovleva
Keyword(s):  
Catalytic Properties ◽  
Raw Materials ◽  
Cold Gas Dynamic Spraying ◽  
Hydrogen Fuel ◽  
Functional Coatings ◽  
Science And Engineering ◽  
Powder Mixtures ◽  
Conversion Of Methane ◽  
Catalytically Active ◽  
Metal Support

The paper considers science and engineering aspects of catalytically active compositions creation as regards immobilized catalysts for reforming hydrocarbon raw materials into hydrogen fuel. The authors investigate synthesis of catalytic powder mixtures and manufacturing of functional coatings by supersonic cold gas dynamic spraying. Research results in the field of creation of catalysts for steam conversion of methane to hydrogenous fuel on the metal support (Cr15Al15 tape support) are given. Composite powder mixtures (Ni–Al–Al(OH)3– Ca(OH)2–Mg(OH)2) were used as starting materials.

O-O bond activation with cobalt(II)-ethylenediamine complexes in ion-exchange resins

1980 ◽  
Vol 45 (6) ◽  
pp. 1780-1784 ◽  
Author(s):  
Atanas Andreev ◽  
Lachezar Prahov ◽  
Dimitar Shopov
Keyword(s):  
Ion Exchange ◽  
Bond Activation ◽  
Catalytic Properties ◽  
Decomposition Reaction ◽  
Ion Exchange Resins ◽  
Hydrogen Peroxide Decomposition ◽  
Surface Complexes ◽  
Peroxide Decomposition ◽  
Epr Parameters ◽  
Exchange Resins

The formation of Oxygen paramagnetic adducts of Co(II) containing ion-exchange resins in the presence of adsorbed ethylenediamine has been found. The EPR parameters of a complex of the type Co(III) (en)2O-2 and of O-2 species formed in the presence of Co(en)2+3 have been described. The catalytic properties of Co-ethylenediamine surface complexes with respect to the hydrogen peroxide decomposition reaction have been investigated and a probable mechanism has been suggested.

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 Effect of linker functionalisation on the catalytic properties of Cu nanoclusters embedded in MOFs in direct CO and CO2 reduction by H2

2021 ◽  
Author(s):  
Cornelia Elizabeth Pompe ◽  
Petra Agota Szilagyi
Keyword(s):  
Catalytic Properties ◽  
Metal Organic Frameworks ◽  
Co2 Reduction ◽  
Catalytically Active ◽  
Metal Organic ◽  
Cu Nanoclusters

Metal-organic frameworks are promising host supporting matrices for catalytically active guest. In particular, their crystallinity renders them desirable as their pores may act as atom-precise templates for the growth of...

scholarly journals Trends of Nitrogen Oxide Release during Thermal Decomposition of Nitrates in Highly Active Liquid Waste

2015 ◽  
Vol 14 (2) ◽  
pp. 86-94 ◽  
Author(s):  
Yuki AMANO ◽  
Koji WATANABE ◽  
Shinsuke TASHIRO ◽  
Yuichi YAMANE ◽  
Jun ISHIKAWA ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Nitrogen Oxide ◽  
Liquid Waste ◽  
Highly Active ◽  
Active Liquid

Preparation of Metallic Cobalt Nanoparticles by the Thermal Decomposition of CoC2O4. 2H2O Precursor in the Argon Gas

2011 ◽  
Vol 127 ◽  
pp. 85-88 ◽  
Author(s):  
Xiao Ming Fu
Keyword(s):  
Thermal Decomposition ◽  
Cobalt Nanoparticles ◽  
Cobalt Powder ◽  
Metallic Cobalt ◽  
Crystal Water ◽  
Argon Gas ◽  
Pyrolytic Decomposition ◽  
Two Stages

Metallic cobalt nanoparticles are successfully obtained by the pyrolytic decomposition of CoC2O4. 2H2O in the argon gas. The pyrolysates of CoC2O4. 2H2O were investigated by TG-DSC and SEM. The results showed that there are two stages in the process of the pyrolytic decomposition of CoC2O4. 2H2O in the argon gas. The crystal water in CoC2O4. 2H2O was lost from 150 °C to 275 °C. CoC2O4was pyrolysized into metallic cobalt powder from 300 °C to 500 °C. At the same time, the pattern of pyolysate of CoC2O4. 2H2O was fined at 347.7 °C for 10 min. But, the particles of pyolysate of CoC2O4. 2H2O were sintered into cobalt blocks at 500.0 °C for 10 min. Therefore, the conditions of pyrolytic decomposition of CoC2O4. 2H2O were controlled if single cobalt powder was obtained at 500.0 °C..

An effective approach for modifying carbonaceous materials with niobium single sites to improve their catalytic properties

2015 ◽  
Vol 44 (46) ◽  
pp. 19956-19965 ◽  
Author(s):  
A. S. Bozzi ◽  
R. L. Lavall ◽  
T. E. Souza ◽  
M. C. Pereira ◽  
P. P. de Souza ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Activated Carbon ◽  
Carbon Materials ◽  
Catalytic Properties ◽  
Carbonaceous Materials ◽  
Simple Route ◽  
Catalytically Active

In this paper we show a very simple route for the incorporation of catalytically active niobium species on the surface of carbon materials, such as graphene oxide, carbon nanotubes and activated carbon.

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