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Showing papers on "Dehydrogenation published in 1980"


Journal ArticleDOI
P. Biloen1, J.N. Helle1, H. Verbeek1, F.M. Dautzenberg1, W.M.H. Sachtler1 
TL;DR: In this article, it was shown that the beneficial effects on catalyst selectivity and stability which are brought about by adding widely different catalyst modifiers (gold, tin, sulfur, carbon) to platinum catalysts are largely due to one common cause, namely, the division of the platinum surface into very small ensembles of platinum atoms.

269 citations


Journal ArticleDOI
TL;DR: In this article, the catalytic decomposition of formic acid was studied on a (110)-oriented copper single-crystal surface and the rate constant was determined to be 9.4 × 10 13 exp ( −31,870 RT ) sec −1.

196 citations


Journal ArticleDOI
TL;DR: In this article, the side-chain alkylation of toluene with methanol has been studied experimentally and a detailed mechanism of the reaction has been investigated by using quantum chemistry.

137 citations


Journal ArticleDOI
TL;DR: In this paper, the hydrogenation and dehydrogenation of cyclohexene have been studied in the pressure range 10−7to 102Torr and the reaction probabilities decrease markedly with increasing pressure.

105 citations



Journal ArticleDOI
TL;DR: In this article, the authors investigated the catalytic properties and catalytic activities of the (12, 9, 8), (10, 8, 7), (654, and (321) platinum crystal surfaces which have (111) terraces, (410), (310) and (210) step orientations with 4.5, 5.9, 9.1 and 20% kink concentrations respectively.

62 citations


Patent
24 Nov 1980
TL;DR: In this article, the attenuated superactive nonacidic multimetallic catalytic composite (ASMMC) is described, which is a combination of a catalytically effective amount of a pyrolyzed rhenium carbonyl component with a porous carrier material containing a uniform dispersion of catalytic effective amounts of an alkali or alkaline earth component.
Abstract: Dehydrogenatable hydrocarbons are dehydrogenated by contacting them, at hydrocarbon dehydrogenation conditions, with a novel attenuated superactive multimetallic catalytic composite comprising a combination of a catalytically effective amount of a pyrolyzed rhenium carbonyl component with a porous carrier material containing a uniform dispersion of catalytically effective amounts of a platinum group component maintained in the elemental metallic state, and of a germanium component. An example of the attenuated superactive nonacidic multimetallic catalytic composite disclosed herein is a combination of a catalytically effective amount of a pyrolyzed rhenium carbonyl component with a porous carrier material containing a uniform dispersion of catalytically effective amounts of an alkali or alkaline earth component, a germanium component, and of a platinum group component which is maintained in the elemental metallic state during the incorporation of the rhenium carbonyl component.

53 citations


Journal ArticleDOI
TL;DR: In this article, the role of 0-1 ions in the oxidative dehydrogenation of ethane over molybdenum oxide supported on silica gel was further studied by comparing the ethane de-hydrogenation kinetics with molecular oxygen and with nitrous oxide (N/sub 2/O) as oxidizing agent.

48 citations




Journal ArticleDOI
TL;DR: In this paper, the authors studied the effect of catalysts with less than 11 wt% MoO3 on O2 chemisorption and cyclohexane dehydrogenation.


Journal ArticleDOI
TL;DR: The stereochemical course of dehydrogenation catalyzed by acyl-CoA oxidase was investigated using the enzymes from rat liver peroxisomes and Candida lipolytica and suggested that acyl -CoA oxidation occurred by anti-elimination of the pro 2R and pro-3R hydrogens of acyl)-CoA.
Abstract: The stereochemical course of dehydrogenation catalyzed by acyl-CoA oxidase was investigated using the enzymes from rat liver peroxisomes and Candida lipolytica. Stearoyl-CoA and nonanoyl-CoA, stereospecifically labeled with deuterium at either C-2 or C-3, were incubated with the enzyme, the products were converted to methyl esters and their deuterium contents were measured by gas chromatography-mass spectrometry. The results suggested that acyl-CoA oxidase-catalyzed dehydrogenation occurred by anti-elimination of the pro 2R and pro-3R hydrogens of acyl-CoA.

Journal ArticleDOI
01 Mar 1980-Fuel
TL;DR: In this paper, the authors show that the nickel-molybdenum catalyst, Cyanamid Aero HDS-3A, has only a mild effect on the conversion of Liddell coal and that this is also the case when the coal is passed through a magnetic separator and then extracted with hydrochloric and hydrofluoric acids before hydrogenation to remove minerals.

Journal ArticleDOI
TL;DR: In this paper, it was shown that, on heating at about 350°C, there is no preferential reduction in the integrated band intensities near 2090 cm−1, assigned to =SiH2 stretching modes, relative to the band near 2000 cm− 1 assigned to the ≡SiH stretching mode.
Abstract: The dehydrogenation of glow-discharge deposited a-Si films has been studied by in situ infrared spectroscopy in order to resolve the apparent inconsistency between the interpretation of previous manometric data and the assignments of the infra-red spectral features in these films. Our studies show that, on heating at about 350°C, there is no preferential reduction in the integrated band intensities near 2090 cm−1, assigned to =SiH2 stretching modes, relative to the band near 2000 cm−1 assigned to the ≡SiH stretching mode. Accepting both infrared assignments our data conflicts with previous proposals that the low temperature dehydrogenation mechanism involves ≡SiH2 groups alone. It appears that the low temperature dehydrogenation proceeds via the molecular elimination of hydrogen from regions in the film where bound hydrogen atoms are in close proximity. These hydrogen atoms may be incorporated either as monohydride or dihydride groups. The model, therefore, allows a consistent interpretation of t...

Patent
01 Aug 1980
TL;DR: A palladium or palladium alloy hydrogen diffusion membrane which has been treated with silane and/or silicon tetrafluoride is employed to separate hydrogen from a hydrocarbon with which it is in admixture and from which it may have been produced under dehydrogenation conditions in the presence of said membrane.
Abstract: A palladium or palladium alloy hydrogen diffusion membrane which has been treated with silane and/or silicon tetrafluoride is employed to separate hydrogen from a hydrocarbon with which it is in admixture and from which it may have been produced under dehydrogenation conditions in the presence of said membrane

Patent
03 Jun 1980
TL;DR: In this paper, a process for producing methyl tert-butyl ether from butane-containing light hydrocarbon mixtures is described, in which the n-butane is isomerized to isobutane, which is then dehydrogenated to a molar ratio of 0.4 to 2:1.
Abstract: A process is described for producing methyl tert.-butyl ether from butane-containing light hydrocarbon mixtures. The n-butane is isomerized to isobutane which is dehydrogenated to an isobutene/isobutane molar ratio of 0.4 to 2:1, the isobutene in the mixture is etherified with methanol to form methyl tert.-butyl ether and the residual isobutane is recycled for dehydrogenation. After the isomerization step, the n-butane and isobutane can be separated and the n-butane recycled. The product containing methyl tert.-butyl ether can be used as a gasoline additive.

Journal ArticleDOI
Toshio Ogino1
TL;DR: The absorption spectrum of a stable organomanganese intermediate in the homogeneously catalyzed permanganate oxidation of endo-dicyclopentadiene in a nonaqueous system was directly determined as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this article, a flow reactor was used over three iron oxide catalysts having different structures, i.e., α-Fe2O3, γ-Fe3, and Fe3O4, which were prepared in situ by controlled reduction and reoxidation with a pulse method.
Abstract: Oxidative dehydrogenation of butenes was investigated by use of a flow reactor over three iron oxide catalysts having different structures, i.e., α-Fe2O3, γ-Fe2O3, and Fe3O4, which were prepared in situ by controlled reduction and reoxidation with a pulse method. Under the working conditions of catalytic oxidation, the structures of α- and γ-Fe2O3 remained unchanged, while Fe3O4 was oxidized to γ-Fe2O3, the oxidation state of iron being Fe(III) in all of three iron oxide catalyst. These results are consistent with the kinetics that the reaction was of zeroth order in the partial pressure of oxygen and of nearly first order in the butene partial pressure. γ-Fe2O3, as well as γ-Fe2O3 formed from Fe3O4 under the catalytic conditions, was very active and selective for the reaction, as expected from the results obtained previously with a pulse reactor. It was concluded from the following facts that the oxygen species responsible for this reaction is lattice oxygen of γ-Fe2O3 and that the reaction proceeds by t...

Journal ArticleDOI
TL;DR: Steroid and triterpenoid ketones can be smoothly dehydrogenated in high yield with benzeneseleninic anhydride in chlorobenzene at 95-120 °C as mentioned in this paper.
Abstract: Steroid and triterpenoid ketones can be smoothly dehydrogenated in high yield with benzeneseleninic anhydride in chlorobenzene at 95–120 °C. With an excess of benzeneseleninic anhydride and longer reaction times 4,4-dimethyl ketones give ring-A-contracted diketones in moderate yield.

Journal ArticleDOI
TL;DR: In this article, a general method for the synthesis of 3-alkylated coumarins is presented. This involves direct Calkylatioa at the C-3 position of 3 carbethoxy-3,4-dihydrocoumarin followed by hydrolysis, decarboxylation and dehydrogenation of the resulting dihydrocoumnin.


Journal ArticleDOI
TL;DR: In this paper, the authors performed efficient de-hydrogenation of indolines to indoles with the catalytic amount of bis(salicylidene)ethylenediaminatocobalt(II) and bis(3-methoxysalicylidsene)methylenediamINATOCobalt (II) under mild conditions in 55-92% yields.
Abstract: Facile dehydrogenations of indolines to indoles were performed with the catalytic amount of bis(salicylidene)ethylenediaminatocobalt(II) and bis(3-methoxysalicylidene)ethylenediaminatocobalt(II) under mild conditions in 55–92% yields.

Journal ArticleDOI
TL;DR: In this paper, it has been shown that PAN fibres are to be heated in the presence of an oxidising atmosphere before carbonisation and that three main reactions take place, namely cyclisation, dehydrogenation and uptake of oxygen in the form of hydroxyl, carbonyl and carboxyl groups.

Journal ArticleDOI
TL;DR: In this paper, the selectivity for oxidative dehydrogenation of butenes increases when zinc is added to the iron oxide catalyst because selective oxidation and complete oxidation proceed on separate sites, as they do on pure iron.
Abstract: Adsorption, temperature-programed desorption, and pulse reaction studies of cis-2-butene and butadiene on spinel zinc ferrite by previously described methods provided evidence that the selectivity for oxidative dehydrogenation of butenes increases when zinc is added to the iron oxide catalyst because selective oxidation and complete oxidation proceed on separate sites, as they do on pure iron; because the density of sites for selective oxidation is higher and the density of sites for complete combustion is lower than on pure iron oxide; and because the activity of the combustion sites is lower.

Patent
28 Feb 1980
TL;DR: In this article, the selectivity of the zinc titanate catalyst is improved by at least one promoter selected from the group consisting of chromium oxide, antimony oxide, bismuth oxide, oxides of the lanthanides, oxide of the actinides, and compounds convertible to the oxides thereof.
Abstract: The catalytic dehydrogenation of at least one dehydrogenatable organic compound which has at least one ##STR1## grouping is carried out in the presence of a zinc titanate catalyst. The selectivity of the zinc titanate catalyst is improved by at least one promoter selected from the group consisting of chromium oxide, antimony oxide, bismuth oxide, oxides of the lanthanides, oxides of the actinides, oxides thereof, and compounds convertible to the oxides thereof.

Journal ArticleDOI
TL;DR: In this paper, the reactions of a series of cyclic and acyclic alkanes in excess hydrogen have been studied on evaporated films of Pt-Au, and the results were rationalized on either an electronic factor or by postulating that gold atoms locate preferentially at rough regions of the surface.
Abstract: The reactions of a series of cyclic and acyclic alkanes in excess hydrogen have been studied on evaporated films of Pt–Au. Film homogeneity was established by X-ray fluorescence spectroscopy and X-ray diffraction.The reactions which occur fall into two groups. First, there are those whose rate is dramatically affected by Au incorporation in Pt, and these include the hydrogenolysis of ethane, neopentane, n-pentane, neohexane and n-hexane, the isomerization of neopentane and n-pentane and finally the ring opening and hydrocracking of the cyclopentane ring. Secondly, there are reactions whose rate is essentially unaffected by moderate Au incorporation in Pt, comprising the 1,5-cyclization of n-pentane, the 1,6-cyclization of n-hexane, the ring enlargement of methylcyclopentane and of 1,1-dimethylcyclopentane and finally dehydrogenation of saturated hydrocarbons to alkene and alkadiene.These results may be rationalized on either an electronic factor or by postulating that gold atoms locate preferentially at rough regions of the surface.

Patent
06 Feb 1980
TL;DR: In this paper, a process for the manufacture of glyoxylic acid esters by catalytic dehydrogenation of glycolic acid ester in the gaseous phase is described.
Abstract: The invention relates to a process for the manufacture of glyoxylic acid esters by catalytic dehydrogenation of glycolic acid esters in the gaseous phase.

Journal ArticleDOI
TL;DR: In this paper, a model is proposed to account for the mode of decomposition of glow-discharge amorphous silicon films and the thermally induced dehydrogenation of these films.
Abstract: Infra-red spectroscopic studies have been made of glow-discharge hydrogenated amorphous silicon films prepared under a variety of experimental conditions. Other studies have been made of the thermally induced dehydrogenation of these films and a model is suggested to account for their mode of decomposition.

Journal ArticleDOI
TL;DR: In this paper, the active center of a calcium-nickel phosphate (Ca/sub 8/Ni(PO/sub 4/sub )/6) catalyst was determined by ESR spectroscopy.