Co-adsorption studies of ethene with isotopically labelled water and hydrogen on copper/silica

The coadsorption of ethene with isotopically labelled water and hydrogen has been studied at temperatures between 423 and 623 K in a flow system. Ethene exchange has been shown to be independent of hydrogenation. When water is presnet, hydrogenation is poisoned but exchange can occur.

---

423–623 . . , .

     

Investigation of thermal decomposition of anthranilates of alkaline earth metals

The thermal properties of calcium, strontium and barium anthranilates (general formula MA₂·n H₂O, whsre M='metal, and) were studied. Thermal, chemical and X-ray analysis, as well as infrared spectra, were used to determine the mechanism of decomposition for these compounds. Calcium anthranilate is decomposed in four stages; the final reaction product is calcium oxide. The other anthranilates are decomposed in three stages; the final reaction products are strontium carbonate and barium carbonate.

---

Zusammenfassung Die thermischen Eigenschaften von Kalzium-, Strontium- und Bariumanthranilat (mit der allgemeinen Zusammensetzung MA₂·n H₂O, M=Metall, wurden untersucht.Die Zersetzungsmechanismen dieser Verbindungen wurden durch thermische, chemische- und Röntgenanalyse und mit Infrarotspektroskopie ermittelt. Kalziumanthranilat zersetzt sich in vier Stufen. Das Endprodukt ist Kalziumoxyd. Die anderen Anthranilate zersetzen sich in drei Stufen und geben Strontiumkarbonat und Bariumkarbonat als Endprodukt.

---

, MA₂·nH₂O, =, , , . . . .

     

Li/MgO catalysts: II. A DTA and TG study of precursors

The thermal decomposition of precursors of Li/MgO catalysts prepared from different Mg and Li compounds is reported. Dehydration and dehydroxylation is observed in both cases, in addition to decomposition of LiNO₃, but not of Li₂CO₃. The properties of the solids are related to the melting and spreading of LiNO₃ or Li₂CO₃ before or after Mg(OH)₂ dehydroxylation.

---

Li/MgO, Mg Li. LiNO₃, Li₂CO₃, . LiNO₃ Li₂CO₃ Mg(OH)₂.

     

Compensation effect in solid-state reactions. Thermolysis of one substance under differing experimental conditions

The compensation effect (lgZ=aE+wb) appearing at the thermolysis of one substance under different experimental conditions is discussed. The compensation effect of one and the same substance has no other physical meaning except the simple confirmation of the analytical relationship between lgZ andE that follows from the Arrhenius equation, and of the impossibility to determineZ from any independent experiment. Values of the coefficienta can not be the measure of the ruptured bond strength.

---

(lgZ=+b), . , lgZ E ( ) Z . a .

     

Non-catalyzed oscillation reaction in aniline-KBrO3?H2SO4 system, I. Potentiometric study of oscillations

The non-catalyzed oscillation reaction of the aniline-KBrO₃–H₂SO₄ system has been followed potentiometrically. The concentration regions of the beginning of oscillation are given in a triangular diagram. Also studied was the dependence of the induction period on concentration of the participants, which was described by a kinetic equation. The oscillation region extends to lower KBrO₃ concentrations, the number of the oscillation jumps increases, and the induction period is shortened with increasing acidity.

---

-KBrO₃–H₂SO₄. . . KBrO₃, .

     

Acid-base properties of Al2O3/MgO oxides, II. Infrared study of adsorption of pyridine

Mixed oxides of alumina and magnesia were characterized by an IR study of pyridine adsorption. Three different Lewis acid sites, but no Brönsted acid sites were detected. The strongest adsorption sites are attributed to Al³⁺ cations of the alumina phase (1455 cm^–1), the weaker Lewis acid sites were assumed to be due to cations of the MgAl₂O₄ phase (1449–1443 cm^–1) and the MgO phase (1440–1438 cm^–1).

---

. , , . Al⁺³ (1455 ^–1), MgAl₂O₄ (1443 ^–1) MgO (1438 ^–1).

     

New oscillating chemical reactions involving copper and nickel tetraazamacrocyclic complexes

Copper and nickel complexes with tetraazamacrocyclic ligands are shown to act as catalysts in Belousov-Zhabotinskii oscillating reactions. New oscillating reactions, viz. the oxidation of unsaturated macrocyclic complexes of copper and nickel by bromate-ions, have been discovered.

---

, -. : - .

     

The role of lattice and adsorbed oxygen in the oxidation of n-butene-1 and furan with MnMoO4-based catalysts

In this paper the adsorption properties towards oxygen and the catalytic oxidation properties of furan and n-butene-1 on a MnMoO₄-based catalyst have been compared. Different forms of adsorbed oxygen are responsible either for the oxidation of furan to maleic anhydride or of furane and n-butene-1 to carbon oxides.

---

--q MnMoO₄. , --1 .

     

Effect of rare earth ions on the catalytic activity of Ln2MnNiO6 perovskites

Abstract A series of rare earth transition metal perovskites has been synthesized and the catalytic activity tested for 2-propanol decomposition. The effect of rare earth ions on the catalytic activity can been understood from the correlations obtained between the physico-chemical properties and the catalytic activity of the perovskites.

---

, , 2-. , - .

     

Influence of the preparation method of precipitated Fe?Mn catalysts on their properties in CO hydrogenation

Studies of the properties of precipitated Fe–Mn catalysts in CO hydrogenation have revealed that samples precipitated from iron and manganese nitrates by sodium carbonate are more selective to olefins than those precipitated by ammonia. Difference in the catalytic properties is due to the different phase compositions of the catalysts.

---

CO , . , , , , . .

     

Coupling of autocatalytic cycles as a possible explanation of chemical oscillators

A general type of oscillating chemical network is presented in which two autocatalytic chemical cycles are coupled by an OR branching, and the second cycle is broached. The results are compatible with the Lotka model and the results of Noszticzius et al. A similar model is proposed also for the Belousov-Zhabotinskii reaction.

---

, «» . . -.

     

Sulfur resistance of Pd complexes with nitrogen and sulfur ligans in hydrogenation reactions

It has been found that homogeneous Pd complexes with sulfur ligands are by 50–500 times more resistant to thiophene action in hydrogenation reactions than homogeneous and heterogenized ones containing nitrogen ligands.

---

50–500 .

     

Cobalt complex with immobilized porphyrin in hydrazine oxidation

Porphyrin immobilized on silica and its complex with cobalt have been prepared and identified. Oxidation kinetics is described by the Michaelis-Menten equation.

---

- . - --.

     

Characterization of titania and zirconia supported molybdenum oxide catalysts by low temperature oxygen chemisorption

Low temperature oxygen chemisorption (LTOC) has been applied to characterize a series of TiO₂ and ZrO₂ supported Mo-oxide catalysts. The monolayer coverage of the surface is completed when the Mo loading reaches 6% and 4% on the TiO₂ and ZrO₂ supports, respectively. The results are explained with the help of a Patch model of the Mo-oxide phase.

---

Mo- TiO₂ ZrO₂ . Mo TiO₂ ZrO₂ 6% 4%, . Patch Mo- .

     

Differential thermal analysis of fluxed melts and its application to the system NiFe2O4-BaO-B2O3

The application of DTA to fluxed melts is discussed, and an apparatus for the determination of the solubility of crystalline materials in molten solutions is described. An exploratory study of the crystallization of nickel ferrite from barium borate fluxes is also described, and solubility curves are presented for fluxes which favour crystal growth. The heat of solution of nickel ferrite was found to be 73 ± 2 Kjoule mole^–1.

---

Zusammenfassung Es wurde über die Anwendung der DTA Methode bei der Untersuchung von Flußmittel enthaltenden Schmelzen berichtet und ein Apparat zur Bestimmung der Löslichkeit von kristallinischen Substanzen in Flüssen beschrieben. Eingehend wurden die Kristallisation von Nickelferrit aus Bariumborat-Flüssen untersucht und Löslichkeitskurven für den Kristallwachstum begünstigende Flüssen gegeben. Die Lösungswärme von Nickelferrit betrug 73 ± 2 Kjoule Mol^–1.

---

Résumé On a décrit l'application de la méthode ATD à l'étude des fusions avec fondant et un appareil adapté à la détermination de la solubilité des substances crystallines dans les fondants. On a étudié la cristallisation de ferrite de nickel des flux de borate de baryum. Des courbes de solubilité pour des flux favorisant les grossissement des cristaux sont présentées. La chaleur de solution du ferrite de nickel a été trouvée 73 ± 2 kjoule mole^–1.

---

A ( ). , . 73±2 ^–1.

     

Physical properties of the catalyst used for the partial oxidation of anthracene to anthraquinone. I. M?ssbauer study

Mössbauer measurements on the intermediate and active material used for partial oxidation of anthracene to anthraquinone are reported. The fraction of ferric and ferrous ions as well as their coordination types are determined.

---

, . , .

     

Ammonium nitrate changes during thermal analysis

A study was made of the difference occurring in ammonium nitrate during investigation by DTA and by DSC. The results show that the DTA of ammonium nitrate (p.a.) is accompanied by the crystal transformation IV III II I and melting. During DSC investigation of the same ammonium nitrate samples, the salt undergoes the transformations IV III and IV II in parallel; then follow the crystal transformations III II I and melting. The investigation conditions and the history of the samples do not essentially influence the crystal transformations during thermal analysis.

---

Zusammenfassung Bei DTA und DSC von Ammoniumnitrat zu beobachtende Unterschiede wurden untersucht. Bei der DTA von p.a. Ammoniumnitrat verlaufen die Kristallumwandlungen IV III II I sowie der Schmelzvorgang. Während der DSC der gleichen Ammoniumnitratproben verlaufen die Übergänge IV III und IV II parallel, worauf die Kristallumwandlungen III II I und der Schmelzvorgang folgen. Die experimentellen Bedingungen und die Vorgeschichte der Proben hat keinen wesentlichen Einfluß auf die während der thermischen Analyse verlaufenden Kristallumwandlungen.

---

. ( ..) IV III II I . , IV III IV II - , III II ar I . .