The catalytic effects of sulfur in ethane dehydroaromatization

The radiation catalytic properties of the BASF K-3-10 catalyst were studied, namely the dependence of these effects on the time interval between the catalyst irradiation and the reaction itself and also on the length of the catalyst use. The catalytic effects decrease exponentially with the interval between the irradiation and the reaction if the catalyst is kept in the presence of air. The stability of effects induced by various types of radiations increases in the sequence beta radiation - gamma radiation - fast neutrons. The radiation catalytic effect stability in the reaction increases in the same sequence.

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Studies of catalysis in fluoride solutions

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1956.0026 ◽

1956 ◽

Vol 234 (1197) ◽

pp. 192-207 ◽

Cited By ~ 6

Keyword(s):

Hydrogen Fluoride ◽

Acid Catalysis ◽

Catalytic Effect ◽

Base Catalysis ◽

Hydrogen Ions ◽

Acid Base ◽

Fluoride Ions ◽

Buffer Solutions ◽

Catalytic Effects ◽

Hydrolysis Of

Measurements are reported of the catalytic effect of aqueous hydrogen fluoride and fluoride buffer solutions in the following eight reactions: the hydrolysis of diethyl acetal, the depolymerization of paraldehyde, the decomposition of nitramide, the bromination of ethyl acetoacetate and of ethyl cyclo pentanone-2-carboxylate, the iodination of acetonylacetone and of acetone, and the dehydration of acetaldehyde hydrate. In the first two, which are specifically catalyzed by hydrogen ions, the catalytic effect of the fluoride systems corresponds to the calculated hydrogen-ion concentrations, and it is suggested that under some conditions fluoride buffer solutions may be particularly useful for controlling pH. In the remaining six reactions there is also general acid-base catalysis by hydrogen fluoride molecules, or by fluoride ions, or by both. The catalytic effects of these two species are close to those predicted by relations previously established for carboxylic acids and their anions. The bifluoride ion has approximately the same effect as hydrogen fluoride in acid catalysis but has no detectable catalytic effect as a base. These findings are discussed in terms of the structures and thermodynamic properties of the species concerned.

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Über den Einfluß äußerer Magnetfelder auf die Aktivität ferromagnetischer Katalysatoren

Zeitschrift für Naturforschung A ◽

10.1515/zna-1953-0904 ◽

1953 ◽

Vol 8 (9) ◽

pp. 538-546 ◽

Cited By ~ 1

Author(s):

E. Justi ◽

G. Vieth

Keyword(s):

Catalytic Activity ◽

Nickel Powder ◽

Catalytic Effect ◽

Theoretical Treatment ◽

High Catalytic Activity ◽

Experimental Proof ◽

Apparent Lack ◽

Low Field ◽

Order Of Magnitude ◽

Catalytic Effects

J.A. Hedvall has discovered “internal” magneto-catalytic effects; the activity of ferromagnetic catalyst changes upon transgressing the Curie-interval. The present publication deals with finding an “external” magneto-catalytic effect consisting of the influence of external magnetic fields upon the activity of ferromagnetic catalysts. This can be shown quite clearly in capillaries of high purity ferromagnetic nickel by experiments applying the o-p-hydrogen conversion. In this reaction the conversion rises so steeply with relatively low field strengths that even the magnetic earth field should enhance the catalytic activity of nickel in compact form; a few hundred oersted may suffice for doubling the conversion and at some 1000 or 10.000 oersted a saturation value of the conversion is reached. The connection between catalytic activity and magnetism finds further support by a corresponding catalytic retentivity.From the theory of ferromagnetism, especially the studies of Néel, it is known that extremely small ferromagnetic particles of the order of magnitude of Blochs walls, i. e. some 10—4 mm, posses high permanent magnetism. This fact appears significant in this connection for the high catalytic activity of finely divided powder catalysts such as Raney catalysts. This permanent magnetism explains also the apparent lack of the external magneto-catalytic effect when using a nickel powder catalyst. The theoretical treatment of the results cannot yet give a definite explanation; before this can be given the experiments must be extended to ordinary chemical reactions. To this end the prerequisits for such experiments are being established.Independently thereof the experimental proof for the external catalytic effect serves to ascertain that the internal Hedvall effects are primarily correlated to the ferromagnetic and paramagnetic states of matter.

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Thermo-Acoustic Catalytic Effect on Oxidizing Woody Torrefaction

Processes ◽

10.3390/pr8111361 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1361 ◽

Cited By ~ 1

Author(s):

Edgar A. Silveira ◽

Luiz Gustavo Oliveira Galvão ◽

Lucélia Alves de Macedo ◽

Isabella A. Sá ◽

Bruno S. Chaves ◽

...

Keyword(s):

Catalytic Effect ◽

Eucalyptus Grandis ◽

Severity Index ◽

Second Step ◽

Strength Analysis ◽

Consecutive Reaction ◽

Acoustic Coupling ◽

Conversion Rates ◽

Mild Pyrolysis ◽

Catalytic Effects

The torrefaction (mild pyrolysis) process modifies biomass chemical and physical properties and is applied as a thermochemical route to upgrade solid fuel. In this work, the catalytic effect of thermo-acoustic on oxidizing woody torrefaction is assessed. The combined effect of two acoustic frequencies (1411, 2696 Hz) and three temperatures (230, 250, and 290 °C) was evaluated through weight loss and its deviation curves, calculated torrefaction severity index (TSI), as well as proximate, calorific, and compression strength analysis of Eucalyptus grandis. A new index to account for the catalytic effects on torrefaction (TCEI) was introduced, providing the quantitative analysis of acoustic frequencies influence. A two-step consecutive reaction numerical model allowed the thermo-acoustic experiment evaluation. For instance, the thermogravimetric profiles revealed that the acoustic field has a catalytic effect on wood torrefaction and enhances the biomass oxidation process for severe treatments. The kinetic simulation of the acoustic coupling resulted in faster conversion rates for the solid pseudo-components showing the boosting effect of acoustic frequencies in anticipating hemicellulose decomposition and enhancing second step oxidizing reaction.

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Catalytic Effect of Active Carbon Black Chezacarb in Wet Oxidation of Phenol

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19961010 ◽

1996 ◽

Vol 61 (7) ◽

pp. 1010-1017 ◽

Cited By ~ 15

Author(s):

Vratislav Tukač ◽

Jiří Hanika

Keyword(s):

Carbon Black ◽

Active Carbon ◽

Catalytic Effect ◽

Copper Catalyst ◽

Copper Catalysts ◽

Wet Oxidation ◽

Waste Waters ◽

Oxidation Of Phenol ◽

Catalytic Effects ◽

Active Carbon Black

The catalytic effects of hydrophilic granulated active carbon black Chezacarb have been tested in the oxidation of dilute (5 000 ppm) aqueous solutions of phenol. The research was focused on combined utilization of sorption and chemical (oxygen functional groups) properties of carbon black which support formation of free radicals in oxidation and on the catalytic effects of metals (Fe, Ni and V) present in the sorbent mentioned. The oxidation was carried out in a stainless steel autoclave of 1.25 l capacity. The reaction temperatures and the total pressures varied in the intervals of 120-160 °C and 3-5 MPa, respectively. The reaction mixture was analyzed by means of HPLC with UV detection (254 nm). The experimental data were evaluated by means of the ASPEN PLUS 9.2 program. The model of laboratory autoclave involved the reaction kinetics as well as the phase equilibria and dissolution of oxygen and carbon dioxide in the reaction mixture. Although the active carbon black shows a lower catalytic activity than the usual copper catalyst in the wet oxidation, it has the advantage of avoiding the undesirable releases of heavy metals in waste waters, which escapes accompany the application of copper catalysts.

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CATALYSIS OF THE CIS-TRANS ISOMERIZATION OF AZOBENZENE BY ACIDS AND CUPRIC SALTS

Canadian Journal of Chemistry ◽

10.1139/v59-278 ◽

1959 ◽

Vol 37 (11) ◽

pp. 1903-1910 ◽

Cited By ~ 18

Author(s):

Stefania Ciccone ◽

J. Halpern

Keyword(s):

Acetic Acid ◽

Hydrochloric Acid ◽

Catalytic Effect ◽

Catalytic Mechanism ◽

Aqueous Ethanol ◽

Metal Salts ◽

Trans Isomerization ◽

Conjugate Acid ◽

Azo Group ◽

Catalytic Effects

The catalytic effects of various acids and metal salts on the cis-trans isomerization of azobenzene in aqueous ethanol were examined kinetically. The effect of perchloric acid is apparently due to H+ ions and is interpreted in terms of a catalytic mechanism involving the conjugate acid of azobenzene. The much greater catalytic effect found for hydrochloric acid is attributed to an additional path involving catalysis by the undissociated acid. Acetic acid was found to be inactive. Of the metal salts examined only those of Cu++ showed pronounced activity which was attributed to co-ordination with the azo group. Kinetic evidence was obtained for a catalytic path involving Cu++ and H+ simultaneously.

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Direct catalytic effect of nitrogen functional groups exposed on graphenic materials when acting cooperatively with Ru nanoparticles

RSC Advances ◽

10.1039/c7ra08774h ◽

2017 ◽

Vol 7 (70) ◽

pp. 44568-44577 ◽

Cited By ~ 6

Author(s):

Carolina Ramirez-Barria ◽

Cristina López-Olmos ◽

Antonio Guerrero-Ruiz ◽

Inmaculada Rodríguez-Ramos

Keyword(s):

Functional Groups ◽

Aqueous Phase ◽

Catalytic Effect ◽

Carbon Materials ◽

Ru Nanoparticles ◽

Phase Oxidation ◽

Furandicarboxylic Acid ◽

Catalytic Effects

Various carbon materials (including doped graphenic materials) have been used as supports of Ru nanoparticles to determine their catalytic effects in the base-free aqueous-phase oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid.

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‘Oxygen-Consuming Complexes’–Catalytic Effects of Iron–Salen Complexes with Dioxygen

Catalysts ◽

10.3390/catal11121462 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1462

Author(s):

Katarzyna Rydel-Ciszek ◽

Tomasz Pacześniak ◽

Anna Miłaczewska ◽

Paweł Chmielarz ◽

Andrzej Sobkowiak

Keyword(s):

Dft Calculations ◽

Catalytic Effect ◽

Active Species ◽

Cyclohexene Oxidation ◽

Effective Catalyst ◽

Salen Complex ◽

Salen Complexes ◽

Catalytic Effects

[(salen)FeIII]+MeCN complex is a useful catalyst for cyclohexene oxidation with dioxygen. As the main products, ketone and alcohol are formed. In acetonitrile, [(salen)FeII]MeCN is rapidly oxidized by dioxygen, forming iron(III) species. Voltammetric electroreduction of the [(salen)FeIII]+MeCN complex in the presence of dioxygen causes the increase in current observed, which indicates the existence of a catalytic effect. Further transformations of the oxygen-activated iron(III) salen complex generate an effective catalyst. Based on the catalytic and electrochemical results, as well as DFT calculations, possible forms of active species in c-C6H10 oxidation have been proposed.

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Acid–Base Catalytic Effects on Reduction of Methanol in Hot Water

Catalysts ◽

10.3390/catal9040373 ◽

2019 ◽

Vol 9 (4) ◽

pp. 373 ◽

Cited By ~ 1

Author(s):

Satoshi Inaba

Keyword(s):

Energy Barrier ◽

Laboratory Experiments ◽

Catalytic Effect ◽

Reduction Rate ◽

Reduction Process ◽

Hot Water ◽

Water Molecules ◽

Acid Base ◽

Catalytic Effects

We have performed a number of quantum chemical simulations to examine the reduction process of methanol in hot water. Methanol is converted into a methane by capturing a hydrogen molecule and leaving a water molecule behind. The required energy for the reduction is too high to proceed in the gas phase. The energy barrier for the reduction of methanol is reduced by the catalytic effect of water molecules when we consider the reduction in aqueous solution. However, the calculated reduction rate is still much slower than that found experimentally. The ion product of water tends to increase in hot water, even though it eventually decreases at the high temperature of supercritical water. It is valuable to consider the acid–base catalytic effects on the reduction of methanol in hot water. The significant reduction of the energy barrier is accomplished by the acid–base catalytic effects due to hydronium or hydroxyde. Mean collision time between a hydronium and a methanol in hot water is shorter than the reduction time, during which a methanol is converted into a methane. The calculated reduction rate with the acid–base catalytic effects agrees well with that determined by laboratory experiments. The present study reveals a crucial role of the acid–base catalytic effects on reactions in hot water.

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Ferrocene and [3]ferrocenophane-based β-diketonato copper(ii) and zinc(ii) complexes: synthesis, crystal structure, electrochemistry and catalytic effect on thermal decomposition of ammonium perchlorate

RSC Advances ◽

10.1039/c6ra02588a ◽

2016 ◽

Vol 6 (41) ◽

pp. 34476-34483 ◽

Cited By ~ 21

Author(s):

Haiying Zhao ◽

Xueyou Zhu ◽

Yadong Shang ◽

Shufeng Chen ◽

Baoguo Li ◽

...

Keyword(s):

Crystal Structure ◽

Thermal Decomposition ◽

Burning Rate ◽

Ammonium Perchlorate ◽

Catalytic Effect ◽

Electrochemical Behaviors ◽

Catalytic Effects

Ferrocene and [3]ferrocenophane-based β-diketonato Cu(ii) complexes exhibit enhanced electrochemical behaviors and burning rate catalytic effects compared with the Zn(ii) complexes.

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