Showing papers on "Dehydrogenation published in 1970"
TL;DR: It was shown that gel‐cell granules which had lost part of their 11‐β‐hydroxylase activity on storage could be reactivated yielding preparations with increased activity.
Abstract: Fungal cells from Curvularia lunata were entrapped in a crosslinked polyacrylamide gel. The gel-cells obtained as granules were applied in the microbial transformation of Reichstein compound S leading to cortisol through an 11-β-hydroxylation step. Some kinetic studies of this conversion using gel-cells were carried out. In addition, it was shown that gel-cell granules which had lost part of their 11-β-hydroxylase activity on storage could be reactivated yielding preparations with increased activity.
From Corynebacterium simplex a steroid dehydrogenase catalyzing the Δ1- dehydrogenation of cortisol leading to prednisolone was isolated and partially purified. The preparation was entrapped in a crosslinked polyacrylamide gel and the gel-enzyme granules obtained used in steroid dehydrogenation processes.
152 citations
TL;DR: The mechanism of the water-gas shift reaction on ZnO and MgO was studied by means of infra-red spectroscopy during the course of the reaction as discussed by the authors.
Abstract: The mechanism of the water-gas shift reaction on ZnO and MgO was studied by means of infra-red spectroscopy during the course of the reaction. When a mixture of carbon dioxide and hydrogen was introduced over ZnO, formate ion was observed. The rate of decomposition (dehydration) of the surface formate ion was measured at the reaction temperature (230°C) as a function of its concentration, and compared with the rate of the overall reaction on ZnO at the same coverage of the surface formate is the reaction intermediate of the water-gas shift reaction on ZnO and its decomposition is the rate-determining step.
When a mixture of carbon monoxide and water vapour was passed over MgO, the formation of surface formate ion was similarly confirmed. It was, however, different from ZnO, in that it was difficult to detect the surface formate ion from a mixture of carbon dioxide and hydrogen. The comparison of the rate of the dehydrogenation decomposition of the surface formate ion with that of the overall reactions at the same formate coverage leads to conclusion that the surface formate ion is the reaction intermediate of the water-gas shift reaction on MgO and the rate determining step is the dehydrogenation of the formate ion.
110 citations
TL;DR: In this paper, a study of the isomerization and dehydrocyclization reactions of hexanes in the presence of inert-alumina-supported platinum catalysts was conducted.
80 citations
Journal Article•
77 citations
TL;DR: Dehydrocyclodimerization is a new process converting C 3, C 4, C 5, C 6, C 7, C 8, C 9 and C 10 paraffins to aromatics as discussed by the authors.
54 citations
Book•
01 Jan 1970
TL;DR: In this paper, the authors define and classify solid acids and bases on solid surfaces and determine acid and base properties on the surfaces of these acids and base classes, including basic and acid-base properties.
Abstract: 1. Definition and Classification of Solid Acids and Bases. 2. Determination of Acidic and Basic Properties on Solid Surfaces. Acidic property. Basic property. Acid-base property. 3. Acid and Base Centers: Structure and Acid-Base Property. Metal oxides. Mixed metal oxides. Clay minerals. Zeolites. Heteropoly compounds. Ion-exchange resins. Metal sulfides. Metal sulfates and phosphates. Superacids. Superbases. 4. Catalytic Activity and Selectivity. Isomerization. Alkylation. Acylation. Transalkylation of alkylaromatics. Hydration of olefins. Conversion of methanol into hydrocarbons. Dehydration. Dehydrohalogenation. Oligomerization and polymerization. Esterification. Hydrolysis. Catalytic cracking. Hydrocracking (hydrogenolysis). Catalytic reforming. Hydrogenation. Dehydrogenation. Oxidation. Miscellaneous. 5. Deactivation and Regeneration. Deactivation. Coke deposition. Coke deposition and deactivation. Regeneration. 6. Related Topics. Gas sensors. Adsorbents. Pressure sensitive recording paper. Cosmetic pigments. Subject Index. Catalyst Index.
54 citations
TL;DR: In this article, the catalytic activity of tetraphenyl porphyrin and phthalocyanine complexes for the heterogeneous dehydrogenation of cyclohexadiene in the gas phase, using nitro-benzene as the oxidizing agent, was measured.
53 citations
TL;DR: In this paper, the bifunctional nature of the bismuth molybdate catalyst is attributed to the presence of two types of MoO3-oxygen bond in the particular structure adopted by MoO 3 in association with Bi2O3.
Abstract: Bismuth–molybdenum–oxide catalysts have been studied by i.r. and u.v. reflectance spectroscopy. Both tetrahedral and octahedral oxomolybdenum(VI) species were at the catalyst surface. The proportion of octahedral species increased with increasing molybdenum concentration and with increasing calcining temperature. The i.r. spectra showed the presence at the surface of an octahedral oxomolybdenum(VI) species with terminal and bridging oxygen. The most active catalysts, including silica-supported catalysts, had characteristic u.v. and i.r. spectra. Molybdenum–terminal oxygen stretching frequencies were in the range found in model compounds with three terminal oxygens per molybdenum. The effect of silica in supported catalysts was to promote formation of the same active species as in the unsupported catalyst but at a higher molybdenum concentration. The relevance of our results to the mechanism of the catalysis of oxidative dehydrogenation of olefines is discussed. We suggest that the bifunctional nature of the bismuth molybdate catalyst is due to the presence of two types of molybdenum–oxygen bond in the particular structure adopted by MoO3 in association with Bi2O3.
39 citations
TL;DR: In this article, the vanadium oxide-alumina catalyst performed better at all pressures than the other catalysts, and was the only vanadium-containing catalyst that performed better than Pt-containing catalysts.
38 citations
TL;DR: In this article, a conjugation mechanism was proposed that involves allyl-HCr(CO)3 complexes as intermediates undergoing 1,3-and 1,5-hydrogen shifts.
Abstract: Various arene-Cr (CO)3 complexes and Cr(CO)6 are effective soluble catalysts for the conjugation of polyunsaturated fats. Methyl benzoate-Cr(CO)3 is one of the most active catalysts. The following conjugation levels were obtained: methyl linoleate, 65%; methyl linolenate, 45%; the polyunsaturates in soybean and safflower oils, 73%; and in linseed oil 48%. Conjugated dienes from linoleate were predominantlycis,trans in configuration. Their double bonds were distributed between C5 and C16 of the fatty acid chain. Hydrogenation and dehydrogenation are side reactions, which seem to limit the yield of conjugated dienes from methyl linoleate. A conjugation mechanism is proposed that involves allyl-HCr(CO)3 complexes as intermediates undergoing 1,3- and 1,5-hydrogen shifts.
37 citations
TL;DR: Platinum has been deposited on a series of silica-alumina supports with different alumina contents, and the dispersion of platinum is found to be constant as mentioned in this paper, indicating the existence of a charge transfer complex between the metal and the oxidizing sites of the support.
TL;DR: The results of the hydrogen-deuterium exchange can be explained if the hydrogen of the rhodium hydride intermediate exchanges with protons from the solvent as discussed by the authors, which can explain some features of the dehydrogenation of isopropyl alcohol to acetone.
Abstract: Rhodium–tin chloride complexes catalyse the dehydrogenation of isopropyl alcohol to acetone and also hydrogen–deuterium exchange between the α-CH and the hydroxy-group of isopropyl alcohol. Reactions (1) and (2) explain some features of the dehydrogenation and the results of the hydrogen–deuterium exchange can be explained if the hydrogen of the rhodium hydride intermediate exchanges with protons from the solvent. Me2CH·OH +[RhIIICl]⇌ Me2CO +[RhIIIH]+ HCl (1), [RhIIIH]+ HCl →[RhCl]III+ H2(2)
Patent•
12 Jan 1970
TL;DR: In this paper, the authors present an example of a combination of PLATINUM, RHENIUM, TUNGSTEN and ALKALI or ALKaline EARTH METAL with a GAMMA-ALUMINA CARRIER MATERIAL in AMOUNTS SUFFICIENT TO RESULT in the COMPOSITE CONTAINing, on an ELEMENTAL BASIS, about 0.05 to 1 WT.
Abstract: DEHYDROGENATABLE HYDROCARBONS ARE DEHYDROGENATED BY CONTACTING THEM AT DEHYDROGENATION CONDITIONS WITH A CATALYTIC COMPOSITE COMPRISING A COMBINATION OF CATALYTICALLY EFFECTIVE AMOUNTS OF A PLATINUM GROUP COMPONENT, A RHENIUM COMPONENT, A GROUP VI TRANSITION METAL COMPONENT AND AN ALKALI OR ALKALINE EARTH METAL COMPONENT WITH A POROUS CARRIER MATERIAL. A SPECIFIC EXAMPLE OF THE CATALYTIC COMPOSITE DISCLOSED HEREIN IS A COMBINATION OF PLATINUM, RHENIUM, TUNGSTEN AND ALKALI OR ALKALINE EARTH METAL WITH A GAMMA-ALUMINA CARRIER MATERIAL IN AMOUNTS SUFFICIENT TO RESULT IN THE COMPOSITE CONTAINING, ON AN ELEMENTAL BASIS, ABOUT 0.05 TO 1 WT. PERCENT PLATINUM, ABOUT 0.05 TO 1 WT. PERCENT RHENIUM, ABOUT 0.01 TO 1 WT. PERCENT TUNGSTEN AND ABOUT 0.1 TO 5 WT. PERCENT OF THE ALKALI OR ALKALINE EARTH METAL.
Patent•
15 Jul 1970TL;DR: In this paper, the group VIII metallers are described as "espECIALLY USEFUL in DEHYDROGENATION PROCESSES and, in addition to improved longevity, can be rePEATEDly regenerated to a CONVERSION ACTIVITY COMMENSURATE with FRESH CATALYSTS".
Abstract: LONGEVITY OF CATALYST COMPOSITES COMPRISING SUPPORTED GROUP VIII METAL COMPOUNDS IS IMPROVED BY INCORPORATION OF A TIN COMPOUND INTO THE SUPPORT PRIOR TO CALCINATION OF THE SUPPORT. AFTER CALCINING OF THE SUPPORT, THE GROUP VIII METAL COMPONENTS ARE INCORPORATED BY CONVENTIONAL PROCEDURES. THE RESULTING CATALYSTS ARE ESPECIALLY USEFUL IN DEHYDROGENATION PROCESSES AND, IN ADDITION TO IMPROVED LONGEVITY, CAN BE REPEATEDLY REGENERATED TO A CONVERSION ACTIVITY COMMENSURATE WITH FRESH CATALYSTS.
Patent•
08 Jun 1970
TL;DR: In this article, the authors used a combination of a PLATINUM COMPONENT, a RHENIUM COMPONent, a TIN COMPONSENT, and an ALKALI OR ALKALTINE EARTH METAL with an ALUMINA CARRIER MATERIAL.
Abstract: DEHYDROGENATABLE HYDROCARBONS ARE DEHYDROGENATED BY CONTACTING THEM AT DEHYDROGENATION CONDITIONS WITH A CATALYTIC COMPOSITE COMPRISING A COMBINATION OF CATALYTICALLY EFFECTIVE AMOUNTS OF A PLATINUM GROUP COMPONENT, A RHENIUM COMPONENT AND A TIN COMPONENT WITH A POROUS CARRIER MATERIAL. IN A PREFERRED EMBODIMENT, THE CATALYST ALSO CONTAINS AN ALKALI OR ALKALINE EARCH COMPONENT. A SPECIFIC EXAMPLE OF THE CATALYTIC COMPOSITE USED IN THIS DEHYDROGENATION METHOD IS A COMBINATION OF A PLATINUM COMPONENT, A RHENIUM COMPONENT, A TIN COMPONENT AND AN ALKALI OR ALKALINE EARTH METAL WITH AN ALUMINA CARRIER MATERIAL.
TL;DR: Protonated mesityl oxide (1,3,3-trimethyl-1-hydroxyallyl cation) has been found to give three reactions, resulting in a large variety of products depending on the acid used as the solvent as mentioned in this paper.
Abstract: Protonated mesityl oxide (1,3,3-trimethyl-1-hydroxyallyl cation, 1) in strong acids has been found to give three reactions, resulting in a large variety of products depending on the acid used as the solvent.
(1) Isomerization, followed by cyclization, gives the 2,5-dimethyltetrahydrofuryl cation, which is about 5 × 103 times stabler than 1. The isomerization, which proceeds via intermediate dications, is acid-catalysed; its rate decreases strongly in the order 1: 1 HF-SbF5 〉〉 9: 1 HF-SbF5 〉 1: 1 FSO3H-SbF5 〉〉〉 5: 1 FSO3H-SbF5.
(2) In FSO3H-SbF5, dehydrogenation with subsequent ring closure to give the 2,4-dihydrofuryl cation.
(3) Cracking produces the acetyl cation and isobutene, which are formed by β-scission of C-protonated mesityl oxide. The isobutene fragment reacts further to give, depending on the acid and the rate at which it is formed, t-butyl cation, or the disulfonic acids of isobutene, or products thereof, and alkylcyclopentenyl ions.
Rate constants of the three reactions in the different solvents have been measured. The 1-ethyl-3,3-dimethyl-1-hydroxyallyl cation (2) reacts in a similar way, but different product selectivities are obtained.
Patent•
27 May 1970TL;DR: In this paper, the authors showed that having the catalyst in zones so that a portion of the oxygen can be injected between zones and mixed with the feed stream can give greatly enhanced yields from a reaction.
Abstract: An oxidative dehydrogenation having the catalyst in zones so that a portion of the oxygen can be injected between zones and mixed with the feed stream can give greatly enhanced yields from a reaction. For example, if a Mg ferrite is used in a single bed a maximum of about .65 mol of O2 per mol of n-butene can be used to give a yield of 61.9% butadiene. The same catalyst in the same volume can give a yield, 77.5% of butadiene with oxygen injection to voids between zones of the catalyst at a ratio of .90 mol of O2 per mol of n-butene. Normally such a high O2/n-butene ratio will result in a severe decrease in selectivity of the reaction and a substantial loss in yield.
TL;DR: In this article, the reactions of primary aliphatic alcohols over reduced nickel oxide catalysts were studied in a micropulse reactor at 160-200 ° at atmospheric pressure and in the presence of a flow of hydrogen.
Patent•
16 Jan 1970TL;DR: In this article, an iron-phosphorus-oxygen (PO4 3 ) catalyst was used for oxidative conversion of olefins and/or diolefs including the dehydrogenation of organic compounds.
Abstract: Oxidative conversion of olefins and/or diolefins including the dehydrogenation of organic compounds is carried out with an ironphosphorus-oxygen catalyst wherein the amount of phosphorus is greater than the stoichiometric amount required to react with all of the iron in the catalyst and form monophosphate ions (PO4 3). The activity of the phosphorus-containing catalyst can be maintained by continuous or intermittent addition of phosphorus containing compounds.
Patent•
03 Jun 1970TL;DR: In this article, the regeneration of deactivated reforming and dehydrogenation catalysts with Group VIII metal contact agents is described, and a process comprising impregnating the deactivated composite material with tin or a tin compound is described.
Abstract: Deactivated catalysts containing Group VIII metal contact agents are regenerated by a process comprising impregnating the deactivated composite material with tin or a tin compound. Preferably, the tin-impregnated composite is thereafter calcined. The process is particularly suitable for the regeneration of deactivated reforming and dehydrogenation catalysts.
Patent•
02 Sep 1970
TL;DR: In this paper, the authors provided a catalyst composition for an oxidation reaction selected from the group consisting of ammoxidation of olefins to nitriles, oxidation of OE to aldehydes and oxidative dehydrogenation of oE to dioLEFins.
Abstract: This invention provides a catalyst composition for an oxidation reaction selected from the group consisting of ammoxidation of olefins to nitriles, oxidation of olefins to aldehydes and oxidative dehydrogenation of olefins (C4 - C8) to diolefins. The catalyst composition has the empirical formula: Fe10 Sb20 60 Me0.01 1 Te0.05 5 Q0.1 20 O40 177 wherein Me is V, Mo and W ; Q is Cu, Ag, Be, Mg, Ca, Sr, Ba, Zn, Cd, La, Ce and Al. The catalyst composition exhibits not only an improved catalytic activity in the reaction but also it shows desirable physical properties particularly fitted for a fluidized-bed reaction.
TL;DR: In this article, the authors studied the de-hydrogenation of methyl-substituted cyclohexanes catalyzed by chromiaalumina and molybdena alumina using the pulse technique.
Patent•
15 Jul 1970
TL;DR: In this article, the authors describe a group of VIII NOBLE METAL, TIN and an INORGANIC, SOLID, this articleACTORY OXIDE CARRIER.
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.
TL;DR: In this paper, the authors investigated the catalytic dehydrogenation of 2-propanol over a Cu-SiO2 catalyst and showed that the undesired side reaction of dehydration can be controlled by a selective catalyst and choice of proper operating conditions.
Abstract: Catalytic dehydrogenation of 2-propanol over Cu-SiO2 catalyst was investigated. The undesired side reaction of dehydration can be controlled by a selective catalyst and choice of proper operating conditions. The kinetics of the heterogeneous catalytic reaction can be adequately expressed by a forward first-order and reverse second-order mechanism. The rate-controlling step with chemically pure 2-propanol is single-site surface reaction, while for the technical grade alcohol the adsorption of alcohol is rate-controlling. The static bed data are compared with the fluidized bed dat
TL;DR: The 3α-cholestanyl ester of 5-(4-benzoylphenyl)-valeric acid underwent direct photochemical hydrogen transfer upon irradiation, thereby providing a simple route to Δ14 and Δ16 steroids, in 53% yield as discussed by the authors.
Abstract: The 3α-cholestanyl ester of 5-(4-benzoylphenyl)-valeric acid underwent direct photochemical hydrogen transfer upon irradiation, thereby providing a simple route to Δ14 and Δ16 steroids, in 53% yield: a minor proportion of this reaction led to steroidal macrolides.
TL;DR: In this article, the N2O-method of Osinga et al. for estimation of bare metallic copper surface on composite copper catalysts has been adapted for use on a gravimetric adsorption unit.
Patent•
16 Jan 1970TL;DR: In this article, a process for disproportionation of saturated hydrocarbons which comprises contacting the saturated hydrocrarbons at a temperature below 850*F and much more preferably below 800*F, and in the presence of no more than 5 weight percent olefin, with a catalytic mass having catalytic activity for dehydrogenation as well as catalytic activation for ole fin disproportionation was described.
Abstract: A process for disproportionation of saturated hydrocarbons which comprises contacting the saturated hydrocrarbons at a temperature below 850*F, and much more preferably below 800*F, and in the presence of no more than 5 weight percent olefin, with a catalytic mass having catalytic activity for dehydrogenation as well as catalytic activity for olefin disproportionation.
Patent•
26 Jun 1970
TL;DR: In this paper, a comparative measure of CATALYTIC COMBINATION of catalytically EFFECTIVE AMOUNTS of a PLATINUM COMPONENT with an ALUMINA CARRIER MATERIAL is presented.
Abstract: A CATALYTIC COMPOSITE, COMPRISING A COMBINATION OF CATALYTICALLY EFFECTIVE AMOUNTS OF A PLATINUM GROUP COMPONENT, A GROUP IV-A METALLIC COMPONENT, A GROUP VA METALLIC COMPONENT AND AN ALKALI OR ALKALINE EARTH COMPONENT WITH AN ALUMINA CARRIER MATERIAL, IS DISCLOSED. A SPECIFIC EXAMPLE OF THE DISCLOSED COMPOSITE IS A CONBINATION OF CATALYTICALLY EFFECTIVE AMOUNTS OF A PLATINUM COMPONENT, A GERMANIUM COMPONENT, AN ARSENIC COMPONENT AND AN ALKALI OR ALKALINE EARTH COMPONENT WITH AN ALUMINA CARRIER MATERIAL. PRINCIPAL USES OF THIS COMPOSITE IS IN A METHOD FOR THE DEHYDROGENATION OF A DEHYDROGENABLE HYDROCARBON AND PARTICULARLY FOR THE DEHYDROGENATION OF LONG CHAIN NORMAL PARAFFINS TO PRODUCE NORMAL MONO-OLEFINS OF THE SAME CARBON NUMBER.