Showing papers on "Dehydrogenation published in 1973"
Esso1
TL;DR: In this paper, it was shown that ruthenium or osmium concentration in the catalysts was held constant at 1 wt% while the atomic ratio of copper-to-RUThenium ratio was varied from 0 to 1.
447 citations
TL;DR: In this paper, structure-reactivity relationships for alcohol elimination reactions were studied over two well-characterized hydroxyapatite catalysts, a stoichiometric preparation (HA) with the composition Ca10(PO4)6(OH)2 and a non-stoichiometric catalyst with CaP = 1.58.
127 citations
TL;DR: In this article, the same authors reported the kinetic data for the dehydrogenation of 2-butanol and hydrogen transfer from this alcohol to 3-pentanone over the same catalysts, showing that both reactions occur on the same sites and involve the same intermediate species.
115 citations
TL;DR: In this paper, the styrene synthesis from ethylbenzene over polynaphthoquinone was investigated in the range of temperature 170-270 °C and no evolution of hydrogen was found in the dehydrogenation reaction.
80 citations
TL;DR: In this article, the role of hexatrienes as intermediates of aromatization has been evaluated in the case of different hexadiene isomers in the presence of hydrogen in the gas phase.
74 citations
Patent•
01 Jun 1973TL;DR: Compositions of a Group VIII noble metal, tin and an inorganic, solid, refractory oxide carrier have excellent dehydrogenation activities and little or no isomerization and cracking activities as mentioned in this paper.
Abstract: Composites of a Group VIII noble metal, tin and an inorganic, solid, refractory oxide carrier have excellent dehydrogenation activities and little or no isomerization and cracking activities.
60 citations
TL;DR: In this article, an intramolecular two stage dehydrogenation process is proposed for coupling of diphenyl ether and diphenylene oxide with coupling dimers, and yields and isomer distributions are attributed to reaction variables such as temperature, additives, and the nature of the substituent on a benzene ring.
Abstract: The oxidative coupling reaction of aromatic compounds proceeds catalytically with palladium salt under oxygen pressure. Yields and isomer distributions are attributed to the reaction variables such as temperature, additives, and the nature of the substituent on a benzene ring. Naphthalene was converted mainly into 1-substituted products and o-xylene into 4-substituted products. The coupling of diphenyl ether afforded diphenylene oxide with coupling dimers. An intramolecular two stage dehydrogenation process is proposed.
60 citations
TL;DR: In this article, the reaction of methylcyclopentane with deuterium has been followed on Ni and Ni-Cu alloy films and the results confirm that reactions at CH bonds are less influenced by alloying than the reactions at cC bonds.
54 citations
52 citations
Patent•
24 Jan 1973
TL;DR: In this article, a multicomponent catalytic composite comprising a combination of catalytically effective amounts of a platinum group component, a tin component and a germanium component with a porous carrier material is presented.
Abstract: Dehydrogenatable hydrocarbons are dehydrogenated by contacting them at dehydrogenation conditions with a multicomponent catalytic composite comprising a combination of catalytically effective amounts of a platinum group component, a tin component, a germanium component and an alkali or alkaline earth component with a porous carrier material. A specific example of the catalytic composite disclosed herein is a combination of a platinum group component, a tin component, a germanium component and an alkali or alkaline earth component with a porous carrier material wherein substantially all of the platinum group component is present as the elemental metal and substantially all of the germanium component is present in an oxidation state above the elemental metal, wherein the composite contains about 0.01 to about 2 wt. % of platinum group metal, about 0.01 to about 5 wt. % tin, about 0.01 to about 5 wt. % germanium and about 0.01 to about 5 wt. % alkali or alkaline earth metal.
50 citations
TL;DR: Results obtained from structural investigations, from inhibitor studies and from the use of labelled substrates with carotenogenic extracts of fungal mutants are discussed in the contexts of the stereochemistry, isomerization and dehydrogenation of phytoene, the pathway of carotene cyclization and the feedback control of the biosynthetic pathway.
Abstract: Studies on Neurospora crassa and mutants of Phycomyces blakesleeanus have led to a reappraisal of a number of important aspects of carotene biosynthesis Results obtained from structural investigations, from inhibitor studies and from the use of labelled substrates with carotenogenic extracts of fungal mutants are discussed in the contexts of the stereochemistry, isomerization and dehydrogenation of phytoene, the pathway of carotene cyclization and the feedback control of the biosynthetic pathway
TL;DR: In this article, it was shown that MnMoO4 exhibits a polyfunctional nature; it is possible to distinguish the properties of isomerization, dehydrogenation, oxidation with oxygen insertion, and complete oxidation by varying parameters such as temperature, oxygen concentration and contact time.
Patent•
29 Nov 1973TL;DR: Gaseous streams containing carbonyl compounds are reduced by reacting a vapor phase with catalyst comprising as the major cation portion at least two metals of Periodic Table Groups 1b, 2b, 4b, 6b, 7b and 8b as discussed by the authors.
Abstract: Gaseous streams containing carbonyl compounds are reduced in carbonyl compounds by reacting a vapor phase with catalyst comprising as the major cation portion at least two metals of Periodic Table Groups 1b, 2b, 4b, 6b, 7b and 8. Reactor effluent from oxidative dehydrogenation reaction to produce butadiene-1,3 is reacted with iron oxide - copper chromite on AMC catalyst to remove carbonyl compounds.
Patent•
14 May 1973TL;DR: In this article, butene was oxidatively dehydrogenated to eg butadiene by use of a catalyst consisting essentially of oxides of molybdenum, cobalt, and boron.
Abstract: Hydrocarbons such as butene may be oxidatively dehydrogenated to eg butadiene by use of a catalyst consisting essentially of oxides of molybdenum, cobalt, and boron.
TL;DR: In this paper, the mechanism of the dehydrogenation of 1,4-cyclohexadienes with triphenylmethylfluoroborate and DDQ is discussed in the light of these results and in view of the kinetic isotope effects.
Abstract: The dehydrogenation of 1,4-cyclohexadiene (1) cis-3,6-dimethyl-1,4-cyclohexadiene (2) and trans-3,6-dimethyl-1,4-cyclohexadiene (3) with triphenylmethylfluoroborate in acetonitrile or 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) proceeds in the same reactivity sequences 2 > 1 > 3. The mechanism of the dehydrogenation of 1,4-cyclohexadienes with triphenylmethylfluoroborate and DDQ is discussed in the light of these results and in view of the kinetic isotope effects.
TL;DR: In this article, the exchange and hydrogenolysis (deuteriumolysis) of thiophene, 2-methylthio-phene, 3methylthiophene and furan were examined over a Mo γ- alumina catalyst.
TL;DR: For example, at 175°C, tosyl cyanide and tetracyclone form 3,4,5,6,tetraphenyl-2-tosylpyridine as discussed by the authors.
Abstract: Tosyl cyanide reacts under extremely mild conditions with 2,3-dimethyl-1,3-butadiene, isoprene and, under somewhat different conditions, with 1,3-butadiene. The products, 2-tosylpyridines and 3,6-dihydro-2-pyridones, are derived by dehydrogenation and hydrolysis, respectively, of the Diels-Alder cyclo-adducts formed in situ. Phenylmethanesulfonyl cyanide and 1-adamantane-sulfonyl cyanide give analogous results with 2,3-dimethylbutadiene.
At 175°C, tosyl cyanide and tetracyclone form 3,4,5,6-tetraphenyl-2-tosylpyridine. Phenylmethanesulfonyl cyanide and p-chlorobenzenesulfonyl cyanide react similarly.
Patent•
01 Jun 1973TL;DR: In this article, a method of pre-preparing a ZINC FERRITE OXIDative DEHYDROGENATION CATalyst is described. But the authors do not specify a method for pre-computing an INSOLUBLE METAL COMPONENT COMPRISING ZINC and IRON.
Abstract: 1. A METHOD OF PREPARING A ZINC FERRITE OXIDATIVE DEHYDROGENATION CATALYST COMPRISING THE STEPS OF (A) CONTACTING A SOLUTION OF A SOLUBLE METAL COMPONENT COMPRISING ZINC AND IRON WITH A PRECIPITATING AGENT TO PRECIPITATE AN INSOLUBLE METAL COMPONENT COMPRISING ZINC AND IRON, SAID SOLUTION CONTAINING IN ADDITION TO THE SOLUBLE METAL COMPONENT FROM 0.1 TO 11 WEIGHT PERCENT OF A SOLUBLE POLYHYDRIC ORGANIC COMPOUND BASED ON THE WEIGHT OF METAL AND (B) CALCINING THE PRECIPITATED TO FORM SAID ZINC FERRITE OXIDATIVE DEHYDROGENATION CATALYST, WHEREIN THE PRECIPITATING AGENT IS A SOLUTION HYDROXIDE OF A METAL SELECTED FROM THE GROUP CONSISTING OF LI, NA, K, RB, AND CS, SAID PRECIPITATING SOLUTION HAVING A NORMALITY OF BETWEEN 2 AND 4 AND SAID POLYHYDRIC COMPOUND CONTAINS AT LEAST 2 HYDROXYL GROUPS AND IS SELECTED FROM THE GROUP CONSISTING OF ORGANIC ALCOHOLS, POLYESTERS, POLYETHERS, POLYSACCHARIDES AND MIXTURES THEREOF HAVING A MOLECULAR WEIGHT OF AT LEAST ABOUT 3,000.
TL;DR: In this article, a model for the transition state and RRKM theory yields a high pressure, unimolecular rate constant for the 1,4-H2 elimination of cis-butene-2 under conditions of very low pressure (VLPP).
Abstract: Pyrolysis of cis-butene-2 under conditions of very low pressure (VLPP) has been studied in the range of 1100–1300°K. The principal products are butadiene and H2, obtained in a unimolecular reaction. A competing reaction to form butene-l accounts for from 10% to 40% of the overall decomposition over the range. Using a «tight» model for the transition state and RRKM theory yields a high-pressure, unimolecular rate constant for the 1,4-H2 elimination of
where θ = 2.303RT in kcal/mol. There is some surface reaction of butadiene at these temperatures to yield H2 + nonvolatile residue. Butene-l proceeds to decompose irreversibly to allyl + methyl radicals which have been observed directly. Comparison with related reactions leads to the conclusion that orbital symmetry-forbidden, 1,2-H2 elimination from saturated organic compounds will have activation energies too high to observe.
Patent•
06 Aug 1973TL;DR: Improved catalysts for oxidative dehydrogenation can be prepared by coprecipitating the metal containing catalysts from a solution of metal ions comprising iron and at least one other metal in the presence of a high molecular weight polyhydric material such as potato starch as mentioned in this paper.
Abstract: Improved catalysts for oxidative dehydrogenation can be prepared by coprecipitating the metal containing catalysts from a solution of metal ions comprising iron and at least one other metal in the presence of a high molecular weight polyhydric material such as potato starch. The result of having the polyhydric material present is that the precipitate has the form of a gelatinous precipitate of improved processability. The catalyst itself is more active in dehydrogenations and physically stronger than comparable catalyst prepared by conventional methods.
Patent•
23 Nov 1973
TL;DR: In this paper, butane was oxidatively dehydrogenated to a mixture of 1-and 2-butenes and butadiene at high space velocities using a catalyst comprising V2O5, K2SO4, SO3 and SiO2.
Abstract: Butane may be oxidatively dehydrogenated to a mixture of 1-and 2-butenes and butadiene at high space velocities using a catalyst comprising V2O5, K2SO4, SO3 and SiO2.
TL;DR: By boiling naphthylene-1,8-diamine with 5-halogeno-2-furyl and 5-nitrofurfural in benzene or xylene, 90% yields of the corresponding 2-(5-halogeneo- 2-fural)- and 2-(1,6,2,3-dihydroperimidines have been obtained.
Abstract: By boiling naphthylene-1,8-diamine with 5-halogeno- and 5-nitrofurfural in benzene or xylene, 90–95% yields of the corresponding 2-(5-halogeno-2-furyl)- and 2-(5-nitro-2-furyl)-2, 3-dihydroperimidines have been obtained. The dehydrogenation of 2-(5-bromo-2-furyl)-2, 3-dihydroperimidine with palladium on carbon has given 2-(5-bromo-2-furyl)perimidine. The compounds obtained have been characterized by their UV and IR spectra.
Patent•
01 Jun 1973
TL;DR: In this article, a nonacidic, multimetallic catalytic composite is described, which is a combination of a platinum component, an iridium component, a germanium component and an alkali or alkaline earth component with an alumina carrier material.
Abstract: Dehydrogenatable hydrocarbons are dehydrogenated by contacting them at dehydrogenation conditions with a nonacidic catalytic composite comprising a combination of catalytically effective amounts of a platinum or palladium component, an iridium component, a Group IVA metallic component and an alkali or alkaline earth component with a porous carrier material. A specific example of the nonacidic, multimetallic catalytic composite disclosed herein is a combination of a platinum component, an iridium component, a germanium component and an alkali or alkaline earth component with an alumina carrier material. The amounts of the catalytically active components contained in this last composite are, on an elemental basis, 0.01 to 2 wt. % platinum, 0.01 to 2 wt. % iridium, 0.01 to 5 wt. % germanium and 0.1 to 5 wt. % of the alkali or alkaline earth metal.
Patent•
26 Oct 1973TL;DR: In this paper, a base catalyst is defined as the calcined residue of a base catalytic residue of mixed phosphates of iron and lead and a modifier component selected from the group consisting of manganese, uranium, praseodymium, calcium, strontium and chromium wherein such modifier is present in the amount of from about 0.1 to about 10% based on the weight of said base catalyst.
Abstract: Lower aliphatic acids, e.g., isobutyric acid and esters, e.g., methyl isobutyrate are dehydrogenated in the presence of oxygen and a solid heterogenous dehydrogenation catalyst at temperatures in the range of from about 250° to about 600° C. The catalyst is the calcined residue of a base catalyst described as the mixed phosphates of iron and lead and a modifier component selected from the group consisting of manganese, uranium, praseodymium, calcium, strontium and chromium wherein such modifier is present in the amount of from about 0.1 to about 10% based on the weight of said base catalyst.
TL;DR: In this article, 2.3-Dihydromaculosidine and 2,3-dihydropteleine were obtained from 2,4-dimethoxy-and 4-methoxyaniline by condensation with diethyl β-benzyloxyethylmalonate, followed by methylation and subsequent cyclodebenzinylation with polyphosphoric acid.
Abstract: 2,3-Dihydromaculosidine and 2,3-dihydropteleine were obtained from 2,4-dimethoxy- and 4-methoxy-aniline by condensation with diethyl β-benzyloxyethylmalonate, followed by methylation and subsequent cyclodebenzylation with polyphosphoric acid. The dehydrogenation of the dihydro compounds with 2,3-dichloro-5,6-dicyanobenzoquinone gave maculosidine (4,6,8-trimethoxyfuro[2,3-b]quinoline) and pteleine (4,6-dimethoxyfuro[2,3-b]quinoline) in relatively high yields. Similarly, evolitrine (4,7-dimethoxyfuro[2,3-b]quinoline) and γ-fagarine (4,8-dimethoxyfuro[2,3-b]quinoline) were also prepared.
Patent•
02 Aug 1973TL;DR: A working solution comprising anthraquinone and its derivatives, used for the production of hydrogen peroxide on becoming degraded by formation of non-effective anthrasquinone, is generated by an auto-oxidation process employing anthrasquone, which comprises: Contacting, at a temperature of below 130°C., and in the presence of a catalyst comprising a metal selected from a platinum group and supported on a carrier, with an olefinic compound whose hydrogenation product is gaseous at said contact temperature, said degraded working solution, which comprising noneffective anth
Abstract: A working solution comprising anthraquinone and its derivatives, used for the production of hydrogen peroxide on becoming degraded by formation of non-effective anthraquinone is generated by an auto-oxidation process employing anthraquinone, which comprises: Contacting, at a temperature of below 130°C., and in the presence of a catalyst comprising a metal selected from a platinum group and supported on a carrier, said degraded working solution, which comprises non-effective anthraquinone and tetrahydroanthraquinone with an olefinic compound whose hydrogenation product is gaseous at said contact temperature and Subsequently, contacting the thus treated working solution, at a temperature above 130°C., and in the presence of a catalyst comprising a metal selected from the platinum group and supported on a carrier, with an olefinic compound whose hydrogenation product is gaseous at said contact temperature, Said method being characterized by the fact that at a temperature below 130°C., the regeneration of non-effective anthraquinone is accelerated much faster than the dehydrogenation reaction of tetrahydroquinone and therefore, at a pont in time, when all non-effective anthraquinone has been converted to anthraquinone, the temperature can be raised above 130°C. to permit dehydrogenation of said tetrahydroanthraquinone without incurring any impedance of the dehydrogenation reaction.
Patent•
10 Sep 1973TL;DR: In this article, butene-2 is dehydrogenated to butadiene over a number of metal vanadites (e.g., Mg, Mn, Co, Zn and Li) in modest to excellent yields.
Abstract: Organic compounds can be oxidatively dehydrogenated using metal vanadite catalysts. For example, butene-2 is dehydrogenated to butadiene over a number of metal vanadites (e.g., Mg, Mn, Co, Zn and Li) in modest to excellent yields. The yield of dehydrogenated product can be improved by the presence of phosphorous in the metal vanadite catalyst, e.g., the yield of butadiene was 45 mole % with a Mg-V catalyst and 50 mole % with a Mg-P-V catalyst under similar conditions of operation. The presence of small quantities of halogen, for example 0.0001 to 0.5 mole per mole of hydrocarbon to be dehydrogenated, produces more improved yields of dehydrogenated product.