Showing papers on "Catalysis published in 1969"
TL;DR: In this paper, the first success in using carbon dioxide as a direct starting material for synthesizing high polymers was reported, which was confirmed with the aid of IR, NMR and elemental analysis.
Abstract: Attempts to copolymerize carbon dioxide with epoxide led us to the first success in using carbon dioxide as a direct starting material for synthesizing high polymers. Some organometallic catalyst systems were found to catalyze the alternate copolymerization of carbon dioxide and epoxide, resulting in the formation of polycarbonates, the structures of which were confirmed with the aid of IR, NMR and elemental analysis. Diethylzinc-water system produced a methanol insoluble aliphatic polycarbonate of much higher molecular weight than that produced by polycondensation. Thermal properties of the methanol insoluble polycarbonate were studied by differential thermal analysis and thermogravimetric analysis.
521 citations
TL;DR: In this paper, the interaction between metal and support, which may complicate the interpretation of data obtained with supported metals, is discussed, and the authors illustrate the use of supported metals for the elucidation of the problem of catalyst specificity.
Abstract: Publisher Summary This chapter describes the interaction between metal and support, which may complicate the interpretation of data obtained with supported metals, the critical problem of determining the surface area of the metal, and illustrates the use of supported metals for the elucidation of the problem of catalyst specificity. Work on the series of platinum catalysts suggests that many reactions of hydrogenation, dehydrogenation, and hydrogenolysis are structure-insensitive. If, these same catalysts are now used in reactions involving oxygen—decomposition of hydrogen peroxide, oxidation of methanol and ethanol, oxidation of acetaldehyde—the picture is substantially altered: while specific rates are again almost the same for highly dispersed samples with percentages of dispersion between 80 and 100%, these specific rates change by at least one order of magnitude on samples with a smaller dispersion (50%) and on platinum black.
508 citations
TL;DR: A method for designing metabolic inhibitors and investigating enzymatic mechanisms at the atomic level and its applications in medicine and materials science.
Abstract: A method for designing metabolic inhibitors and investigating enzymatic mechanisms at the atomic level.
369 citations
TL;DR: In this paper, the authors investigated the influence of K2O on the heat of adsorption of CO, CO2 and H2 on unpromoted, on singly and on doubly promoted reduced magnetite.
292 citations
TL;DR: The catalytic properties of the catalytic catalyst cobalt molybdate on alumina were investigated with the help of a microreactor pulse technique under chromatographic conditions.
219 citations
TL;DR: In this article, the adsorption and catalytic reaction of oxygen and carbon monoxide on a Pd(110) surface has been studied by means of low energy electron diffraction (LEED) and mass spectrometric techniques.
200 citations
TL;DR: In this article, it was shown that the chemical properties of a metal catalyst are not determined by collective properties of the catalyst, such as the filling of its d-band, but by the properties of its individual surface atoms, i.e., the bond strength between the adsorbing atom and the adsorbate.
177 citations
Patent•
11 Mar 1969TL;DR: In this article, it is stated that it is preferred that the HYDROGEN FLUORIDE TREATMENT be ACCOMPLISHED after THOSE PREPARATION STEPS REQUIRING CONTACT of the ZEOLITE with WATER at high temperature.
Abstract: IMPROVED HYDROCARBON CATALYSTS ARE PREPARED BY TREATING CERTAIN ZEOLITES WITH HYDROGEN FLUORIDE. IT IS PREFERRED THAT THE HYDROGEN FLUORIDE TREATMENT BE ACCOMPLISHED AFTER THOSE PREPARATION STEPS REQUIRING CONTACT OF THE ZEOLITE WITH WATER AT HIGH TEMPERATURES. IT IS ALSO PREFERRED THAT THE ZEOLITE WHICH IS SUBJECTED TO THE HF TREATMENT HAVE A SUBSTANTIAL PORTION OF IS ALKALI METAL CONTENT REPLACED BY THE HYDROGEN ION.
172 citations
TL;DR: In this paper, a study on the reaction of nitrous oxide with copper surfaces was made, where the reaction at 90°C and 20 cmHg gave a coverage of about unity, and was used for determining free-copper surface areas of catalysts.
Abstract: A study is made on the reaction of nitrous oxide with copper surfaces. As with germanium, the reaction has an activation energy that increases with coverage. The transition from surface to bulk oxidation sometimes involves an incubation time. The reaction at 90°C and 20 cmHg gives a coverage of about unity, and is used for determining free-copper surface areas of catalysts. The results are compared with those of X-ray line broadening and electron microscopy. Emmett and Skau's carbon monoxide method for determining free-copper surface areas is briefly discussed.
160 citations
TL;DR: In this article, the catalytic decomposition of dilute aqueous solutions of hydrogen peroxide has been studied on a number of Group VIII metals and binary alloys, including palladium-gold.
TL;DR: In this paper, the catalytic properties of a series of sodium hydrogen Y zeolites have been studied as a function of the zeolitic sodium content, and the structural hydroxyl groups were investigated after the zeolite had been calcined at 480 °C.
TL;DR: In this paper, the structure determination of the cobalt molybdate on alumina catalyst has been studied and it is shown that the cobalo-molybdenum is distributed throughout the bulk of the alumina as CoAl 2 O 4, whereas the molybenzenum is spread over the carrier surface, probably as a monomolecular layer.
Patent•
25 Jul 1969
TL;DR: In this paper, an improved version of the ZIEGLER-type catalyst is used to reduce the amount of a carrier in the transition metal and ORGANOMETALLIC component.
Abstract: A PROCESS FOR POLYMERIZING AND/OR COPOLYMERIZING OLEFINS BY USING AN IMPROVED CATALYST CONSISTING OF A TRANSITION METAL COMPOUND SUPPORTED ON ELECTRONDONOR-PRETREATED INORGANIC SOLID PARTICLES TE TRANSITION METAL COMPOUND BEING A COMPONENT OF A ZIEGLER-TYPE CATALYST, AND AN ORGANOMETALLIC COMPOUND, WHEREBY THE POLYMERIZATION ACTIVITY OF THE CATALYST PER UNIT WEIGHT BOTH OF THE TRANSITION METAL AND ORGANOMETALLIC COMPONENT REMARKABLY INCREASES, THUS MAKING IT POSSIBLE TO REDUCE AN AMOUNT OF A CARRIER WHCH REMAINS IN THE RESULTANT POLYMER CAUSING INCREASED ASH CONTENT, AND ALSO POSSIBLE TO EASILY CONTROL THE MELT-INDEX OF THE RESULTANT POLYMER.
TL;DR: In this article, the interaction of confugated and cumulated dienes with π-allylic palladium complexes is described as part of palladium-catalysed synthesis of polyunsaturated carboxylic acid derivatives from a diene, an alcohol and carbon monoxide or from an allylic compound and carbon dioxide.
TL;DR: In this paper, a detailed comparative study of various catalysts for the hydrogenolysis of spruce wood lignin was made, including Raney nickel, 10% palladium-charcoal, and 5% Raney copper.
Abstract: A detailed comparative study has been made of the effectiveness of various catalysts for the hydrogenolysis of spruce wood lignin. The catalysts studied were Raney nickel, 10% palladium–charcoal, 5...
TL;DR: In this paper, the authors describe the unsupported chromia as a catalyst for relatively low temperature reactions under reducing conditions, and provide an outline of the wide variety of reactions catalyzed by chromia or supported chromia.
Abstract: Publisher Summary The catalytic properties of chromia have received considerable attention, probably more than those of any other catalysts except Group VIII metals, silica, and alumina. This chapter describes the unsupported chromia as a catalyst for relatively low temperature reactions under reducing conditions, and provides an outline of the wide variety of reactions catalyzed by chromia or supported chromia. A chromia gel activated only at 150° has no detectable catalytic activity for the hydrogenation of olefins at room temperatures nor does it chemisorb oxygen or carbon monoxide. Catalytic and adsorptive capacity develops upon pretreating the gel at higher temperatures. After heating to 400°, chromia rapidly chemisorbs oxygen and carbon monoxide at −78° and it leads to rapid hydrogenation of ethylene at −78°. The surface of chromia appears to be an ideal case for study at the present. By activation at increasing temperatures, one can vary the number of active sites from none to some maximum number. At a low density of sites, one can hope that the sites are well separated and non-interacting. One can compare chemisorption of various gases with specific catalytic activities at various levels of site densities and hope to gain information about site heterogeneity.
TL;DR: The catalytic activity for o-xylene isomerization and the acidity, as measured by infrared studies of chemisorbed pyridine, of rare earth Y zeolite have been investigated as mentioned in this paper.
TL;DR: In this paper, the kinetics of methanol oxidation over MoO3Fe2(MoO4)3 catalyst were studied by means of a differential flow reactor and a pulse reactor in the temperature range 180-280 °C.
TL;DR: The desulfurization rates in hydrogen of thiophene, tetrahydrothiophene and n-butanethiol over molybdenum disulfide, an alumina supported cobalt molydate, and a chromia catalyst have been measured as mentioned in this paper.
Abstract: The desulfurization rates in hydrogen of thiophene, tetrahydrothiophene, and n-butanethiol over molybdenum disulfide, an alumina supported cobalt molybdate, and a chromia catalyst have been measure...
TL;DR: In this article, the authors examined the mechanisms of the formation of methane from carbon monoxide and dioxide and hydrogen in the presence of contact catalysts based on metals of the iron group (chiefly nickel).
Abstract: The present review examines the mechanisms of the formation of methane from carbon monoxide and dioxide and hydrogen in the presence of contact catalysts based on metals of the iron group (chiefly nickel). The experimental results obtained by various methods are examined, the reactive forms of the adsorbed molecules and the signs of their charges are considered, and particular attention is paid to the determination of the reactive complexes under the conditions preceding the start of the catalytic reaction, and the results of kinetic studies. It is shown that there is a significant difference in the mechanisms of the hydrogenation of carbon monoxide and dioxide to methane. This difference is attributed to the poisoning effect of carbon monoxide on the processes involved in the hydrogenation of CO2. Attention is drawn to a number of results which are of considerable importance for the solution of the problems of the catalytic purification of hydrogen from oxides of carbon. The bibliography contains 129 references.
Patent•
25 Jun 1969
TL;DR: In this paper, a reaction product of MAGNESIUM ALCOHOLATES with TETRAVALENT HALOGENATED TITANIUM and ORGANO-ALUMINUM COMPOUNDS is described.
Abstract: PROCESS FOR HOMO- AND COPOLYMERIZING OLEFINS IN THE PRESENCE OF A MIXED CATALYST COMPRISING, AS COMPONENT A, A REACTION PRODUCT OF MAGNESIUM ALCOHOLATES WITH TETRAVALENT HALOGENATED TITANIUM COMPOUNDS AND, AS COMPONENT B, ORGANO-ALUMINUM COMPOUNDS. ALREADY UNDER A PRESSURE OF LESS THAN 20 ATMOSPHERES THE YIELDS PER CATALYST OBTAINED ARE SO HIGH THAT THE REMAINDERS OF CATALYST NEED NOT BE REMOVED FROM THE POLYMER. OPTIONALLY, PRODUCTS CAN ALSO BE PREPARED WHICH HAVE A VERY NARROW MOLECULAR WEIGHT DISTRIBUTION AND VERY GOOD COLOR AND CORROSION VALUES.
TL;DR: In this article, the specific activity for ethylene hydrogenation was measured over Pt/silica catalysts in which the mean crystallite size was varied from 13 to 200 A. The results showed that the catalysts were prepared by adsorption of the ammine or by impregnation with chloroplatinic acid, dried or fired in air and reduced in hydrogen under various conditions.
Patent•
20 Oct 1969
TL;DR: A VAPOR PHASE CATALYTICODEDEHYDROGENATION as discussed by the authors process for the conversion of a stream of MIXED ISOMERIC ISOAMYLENES, METHYL BUTANOLS or MIXTURES THEREOF to ISOPRENE with RELATIVELY SHORT contact times at a Reactor TEMPERATURE in the range of 500*F to 1100*F.
Abstract: A VAPOR PHASE CATALYTIC OXYDEHYDROGENATION PROCESS FOR THE CONVERSION OF A STREAM OF MIXED ISOMERIC ISOAMYLENES, METHYL BUTANOLS OR MIXTURES THEREOF TO ISOPRENE WITH RELATIVELY SHORT CONTACT TIMES AT A REACTOR TEMPERATURE IN THE RANGE OF 500*F. TO 1100*F. AT FROM 0.5 TO ABOUT 10 ATMOSPHERES PRESSURE. THE CATALYSTS COMPRISE AN ALKALI METAL AS AN ESSENTIAL CATALYTIC INGREDIENT.
TL;DR: In this article, it was shown that carbon dioxide is not absorbed by the electrolyte and therefore it is possible to use organic fuels, either direct or by reforming them with water vapour, without removing the resultant carbon dioxide.
Abstract: FUEL cells with acid electrolyte, such as dilute sulphuric acid, have the advantage over those with alkaline electrolyte that carbon dioxide is not absorbed by the electrolyte. In principle it is therefore possible to use organic fuels, either direct or by reforming them with water vapour, without removing the resultant carbon dioxide. Even if carbon-free fuels such as hydrogen or hydrazine are used, an acid electrolyte should be preferred, for carbon dioxide need not be removed from the air. In the past, however, no acid-resistant catalyst has been found that might replace expensive and easily poisoned platinum.