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1.
The influence of the pH of precipitation and the ionic medium nature on the composition, surface charge, and kinetic sorption characteristics of aluminum oxyhydroxides formed by alkaline hydrolysis of an aqueous solution of aluminum nitrate was studied. The methods of drop titration with alkali, argentometric titration, point of zero charge, and indicator reactions of heterogeneous hydrolysis were used. The composition of the freshly precipitated hydrogels of aluminum(iii) oxyhydroxide, rate constants of heterogeneous hydrolysis of the IrCl6
2– ions as indicator reactions, and the pH of the point of zero charge were determined. The rate of indicator reactions (as for other oxyhydroxide hydrogels) depends strongly on the pH of precipitation. However, it is lower than the rates characteristics of iron(iii) and chromium(iii) oxyhydroxides obtained under similar conditions. The pH of the point of zero charge for the alumogels in a chloride medium is 8.3 and that in a sulfate medium is 9.5. 相似文献
2.
D. P. Domonov S. I. Pechenyuk N. L. Mikhailova A. T. Belyaevskii 《Russian Journal of Inorganic Chemistry》2007,52(7):1027-1032
The thermolysis of the complexes [Co(NH3)6]2C2O4[Cu(C2O4)2]2 (I) and [Co(NH3)6]Cl[Cu(C7H4O3)2] (II) in air and hydrogen at 200, 350, and 500°C and the composition and properties of the thermolysis products are considered.
The oxidative thermolysis of the complexes yields mixtures of cobalt and copper oxides, including mixed ones. The reductive
thermolysis of the complexes yields a Co + Cu bimetallic powder in the case of compound I and a Co + Cu + C powder in the
case of compound II. The thermal behavior of the complexes is governed by the nature of the ligand coordinated to the copper
atom. The observed data are explicable in terms of the properties of this ligand. The chemistry of the oxidative and reductive
thermolysis is discussed.
Original Russian Text ? D.P. Domonov, S.I. Pechenyuk, N.L. Mikhailova, A.T. Belyaevskii, 2007, published in Zhurnal Neorganicheskoi
Khimii, 2007, Vol. 52, No. 7, pp. 1104–1110. 相似文献
3.
Gosteva Alevtina N. Plyusnin Pavel E. Semushina Yulya P. Pechenyuk Sofiya I. Filatov Evgeny Yu. Kyrtova Olga Yu. 《Journal of Thermal Analysis and Calorimetry》2018,134(1):253-260
Journal of Thermal Analysis and Calorimetry - The thermal behavior of double complex compounds (DCC) [Cr(ur)6][Co(CN)6]·4H2O (I), [Cr(ur)6][Co(C2O4)3]·3.5H2O (II),... 相似文献
4.
S. I. Pechenyuk 《Russian Chemical Bulletin》1999,48(6):1017-1023
The modern theoretical views on the point of zero charge of the oxide hydroxide surface are considered. Methods for determination
of the pH of the point of zero charge and the use of this value to characterize the properties of oxide hydroxides are described.
Examples of using the pH of the point of zero charge in studies of oxide anodes and amorphous oxide hydroxide sorbents are
presented.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1029–1035, June, 1999. 相似文献
5.
S. I. Pechenyuk D. P. Domonov A. N. Gosteva G. I. Kadyrova V. T. Kalinnikov 《Russian Journal of Coordination Chemistry》2012,38(9):596-603
Binary complex salts, [Co(En)3][Fe(CN)6] · 2H2O and [Co(En)3]4[Fe(CN)6]3 · 15H2O, are synthesized. The properties of the salts and their thermolysis in air, dihydrogen, and argon are studied. Oxides of the central ions of the binary complex salts are found to be the thermolysis products in an oxidative atmosphere. Solid solutions (intermetallic compounds) CoFe are the thermolysis products in the reductive atmosphere, whereas intermetallides containing considerable amounts of C and N and an impurity of Co and Fe oxides are the thermolysis products in an inert atmosphere. Gaseous thermolysis products in dihydrogen and argon are NH3, hydrocarbons, and ethylenediamine. 相似文献
6.
A procedure for pH-metric determination of the limiting adsorption of OH groups (A
OH) by FeIII, ZrIV, CrIII, and InIII oxyhydroxide hydrogels from 0.1 and 1.0 M solutions of NaCl is described. Data on the molecular area occupied by a single OH group on the hydrogel surface (S
OH) and the S
spec values, which were calculated from A
OH and S
OH, are presented. The S
spec value does not depend on the pH of hydrogel precipitation; the true S
spec value can be determined only from sorption of the OH groups at the actual point of zero charge of the hydrogel. The A
OH values for hydrogels were found to change only slightly during aging of hydrogels in electrolyte solutions. 相似文献
7.
S. I. Pechenyuk D. P. Domonov D. L. Rogachev A. T. Belyavskii 《Russian Journal of Inorganic Chemistry》2007,52(7):1033-1038
The thermolysis of complexes [Co(NH3)6][Fe(CN)6] and [Co(NH3
6]4[Fe(CN)6]3 under an air or hydrogen atmosphere at 200, 350, and 500°C is studied. The composition and properties of thermolysis products
are determined. The oxidative thermolysis yields mixtures of oxides of the central metals; the reductive thermolysis yields
intermetallic compounds CoFe. The density of the complexes and the specific surface area of the intermetallic compounds are
measured. Average particle sizes are calculated. The morphology and dispersion of the powders are dictated by the shape and
density of the crystals of the precursor double salts and the thermolysis temperature. The thermolysis chemism in the oxidative
and reductive atmospheres is discussed in the context of the nature of the complex anion.
Original Russian Text ? S.I. Pechenyuk, D.P. Domonov, D.L. Rogachev, A.T. Belyavskii, 2007, published in Zhurnal Neorganicheskoi
Khimii, 2007, Vol. 52, No. 7, pp. 1110–1115. 相似文献
8.
S. I. Pechenyuk L. P. Kuzmich 《Colloids and surfaces. A, Physicochemical and engineering aspects》2001,180(3):259-266
Adsorption properties of Ti(IV), Zr(IV), In(III), Cr(III) and Fe(III) oxyhydroxides aged in sodium chloride and sulphate solutions have been studied. The main research method was determination the rates of heterogeneous hydrolysis reactions for RhCl63− and IrCl62− complexes. The rate constants of these reactions were a measure of adsorption activity of the oxyhydroxides on which surface they occur. For comparison the corresponding data for freshly formed oxyhydroxides are presented. It was found that adsorption activity (the values of rate constants Kobs) of ferro- and indiogels decrease slowly with increasing of duration and temperature of ageing. The sulphate electrolyte promotes the decrease of sorption activity more than chloride electrolyte. In contrast, the samples of titano- and chromogels aged during 2 h at 80°C have much greater adsorption activity than freshly formed ones, and this activation holds for a very long time. The zirconogel keeps in these conditions stable adsorption activity for a very long time. Apparently, after precipitation the chromo-, titano- and zirconogels some metastable non-crystalline or micro-crystalline structures stable to further ageing form rapidly. The oxyhydroxides behaviour is obviously connected with the electronic structure of outer electronic shell of their central ions. The chromium(III) oxyhydroxide with a unsymmetrical, partially filled 3d-sublevel is the most effective sorbent and has the most stable sorption properties. 相似文献
9.
D. P. Domonov S. I. Pechenyuk A. N. Gosteva 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2014,88(6):913-918
Samples are obtained via the thermolysis of binary complex compounds in a hydrogen atmosphere. Their catalytic activity in hydrogen peroxide decomposition is studied. The values of the rate constants and activation energies for the catalytic reaction are estimated. The correlation between catalytic activity, composition, specific surface area (S sp), and particle size of the samples is analyzed. 相似文献
10.
S. I. Pechenyuk D. P. Domonov A. A. Avedisyan S. V. Ikorskii 《Russian Journal of Inorganic Chemistry》2010,55(5):734-738
Thermal decomposition of binary complexes [M(NH3)
k
]
x
[M′L
n
]
y
(M = Ni, Co; M′ = Fe, Cr, Cu; L = CN−, SCN−, C2O42−) in a hydrogen atmosphere showed conversion of coordinated CN− groups into ammonia and hydrocarbons; SCN− into ammonia, hydrogen sulfide, and hydrocarbons; and C2O42− into hydrocarbons and CO2. In all cases, methane prevails in the resulting hydrocarbons; ethylene is the second in relative yield, which however strongly
depends on the temperature and combination of the central ions of double complex salts. The yield of ethylene is especially
high from the reduction of Co-Fe complexes at 350°C, Co4-Fe3 complexes at 500°C, Ni3-Fe2 and Ni3-Cr2 complexes at 350°C. The observed conversions of coordinated groups can be interpreted as arising from the catalytic effect
caused by the reduced forms of the central atoms in the binary complexes to the interaction of ligands with hydrogen. 相似文献