Showing papers on "Catalysis published in 1983"
Book•
01 Jan 1983
TL;DR: Energy resources through photochemistry and catalysis as discussed by the authors have also been used for energy and mineral resources in the field of computer science. But, they have not been used in the area of renewable energy.
Abstract: energy resources through photochemistry and catalysis pdf ebook energy resources through photochemistry and catalysis ebook energy resources through photochemistry and catalysis energy resources through photochemistry and catalysis energy resources through photochemistry and catalysis energy resources through photochemistry and catalysis organometallics and catalysis pdf firebase light harvesting and energy transfer in laser dye-labeled nanotechnology in catalysis nanostructure science and free download section 4 1 energy and mineral resources kids guide to types of landforms childrens science nature photochemistry and photophysics of hyper porphyrins solar photochemistry office of science 2000 gmc w3500 manual quafe free download section 4 2 alternate energy resources homogeneous and heterogeneous photocatalysis springer free download energy and resources section 1 reinforcement malory and christianity essays on sir thomas malorys morte nazaryth [the exiled 1] (siren publishing everlasting free download energy resources wordsearch answers cad managers guidebook paycox photoelectrochemical reduction of co2 using silicate rock tier unit 3 1 day fourscorched earth ebook | ufcgymmatthews how to troubleshoot a tv receiver dioro bien dit french 2 workbook answers alongz size effects in photoprocesses on dispersed catalysts department of chemistry, university of texas, austin basic energy sciences overview
671 citations
TL;DR: In this article, an efficient photogeneration of either (CO + H2) simultaneously, or CO selectively, occurs on visible light irradiation of CO2 solutions in (HOCH2CH2)3N-dimethylformamide containing, respectively, Ru(bipy)32+−Co2+ combinations or the single component Re(Bipy)(CO)3X (X = Cl, Br) as homogeneous catalysts.
Abstract: Efficient photogeneration of either (CO + H2) simultaneously, or CO selectively, occurs on visible light irradiation of CO2 solutions in (HOCH2CH2)3N–dimethylformamide containing, respectively, Ru(bipy)32+–Co2+ combinations or the single component Re(bipy)(CO)3X (X = Cl, Br) as homogeneous catalysts.
550 citations
TL;DR: Extracellular microbial lipases can be used as catalysts for the interesterification of oils and fats as discussed by the authors, which gives products which are unobtainable by chemical interesterization methods.
Abstract: Extracellular microbial lipases can be used as catalysts for the interesterification of oils and fats. Use of specific lipases gives products which are unobtainable by chemical interesterification methods. Some of these products have properties of value to the oils and fats industry. The catalysts for enzymatic interesterification are prepared by coating inorganic support materials with the lipases. For batch interesterification reactions, the catalyst particles are activated by addition of a small amount of water and then stirred with a reactant mixture dissolved in petroleum ether. At the end of the reaction period, the catalyst particles are removed by filtration, and the interesterified triglycerides isolated by conventional fat fractionation techniques. The catalyst can be used in subsequent batch reactions. As an alternative to the batch reaction system, continuous enzymatic interesterification processes can be operated by pumping water containg feedstock through a packed bed of activated catalyst.
452 citations
TL;DR: A novel, enzymatic approach has been developed for the removal of phenols from coal-conversion aqueous effluents using horseradish peroxidase and hydrogen peroxide.
Abstract: A novel, enzymatic approach has been developed for the removal of phenols from coal-conversion aqueous effluents. Treatment with horseradish peroxidase and hydrogen peroxide precipitates 97 to 99 percent of the phenol in a wide range of pH and phenol concentrations; both model mixtures and real industrial waste-water samples have been treated successfully. Other pollutants, such as polychlorinated biphenyls, can be enzymatically coprecipitated with the phenols.
433 citations
TL;DR: In this paper, a temperature-programmed desorption (TPD) experiment on a supported metal catalyst is described, where a small amount of catalyst (10-200 mg) is contained in a reactor that can be heated by a furnace.
Abstract: In a typical temperature-programmed desorption (TPD) experiment on a supported metal catalyst, a small amount of catalyst (10–200 mg) is contained in a reactor that can be heated by a furnace. An inert gas, usually helium at atmospheric pressure, flows over the catalyst. Following pretreatment to obtain a reduced catalyst, a gas is adsorbed on the surface, usually by pulse injections of the adsorbate into the carrier gas upstream from the reactor. After the excess gas is flushed out, the catalyst is heated to create a linear rise in temperature with time. A small thermocouple inserted in the catalyst measures the temperature and a detector downstream measures the change in the inert gas stream. The ideal detector is a mass spectrometer which measures the composition of the effluent stream as a function of catalyst temperature. Because of the high carrier-gas flow rate, the detector response is proportional to the rate of desorption if diffusion and readsorption are not limiting.
426 citations
TL;DR: The catalytic effects of alkali metal salts in the gasification of carbonaceous materials by oxygen, steam and carbon dioxide are described in this article, and current theories of the mechanism of this type of catalysis are reviewed.
424 citations
421 citations
TL;DR: In this paper, the complete mineralization of trichloroethylene (Cl2CCClH) in dilute aqueous solutions, to HCl and CO2, was demonstrated with heterogeneous photoassisted catalysis using illuminated titanium dioxide (TiO2).
418 citations
TL;DR: Epoxydation asymetrique d'olefines prochirales par des porphyrines de fer chirales and par des composes iodosyles.
Abstract: Epoxydation asymetrique d'olefines prochirales par des porphyrines de fer chirales et par des composes iodosyles
416 citations
TL;DR: The chromatographic technique for determining the specific copper surface area of catalysts by reaction with nitrous oxide has been investigated in this paper, where the application of a single pulse of Nitrous oxide in excess of that required to oxidize an the surface copper and a temperature of 90°C has been shown to provide a reliable measurement of specific copper surfaces.
401 citations
TL;DR: In this article, a nouveau catalyseur is constitue par une association d'ions tungstate et phosphate dans des conditions acides, in which tungstane and phosphate are used.
Abstract: Ce nouveau catalyseur est constitue par une association d'ions tungstate et phosphate dans des conditions acides
Patent•
06 Jun 1983TL;DR: In this paper, a broad molecular weight distribution is obtained by polymerizing ethylene or higher alpha-olefins in the presence of a catalyst system comprising two or more metallocenes each having different propagation and termination rate constants and alumoxane.
Abstract: Polyolefins having a broad molecular weight distribution are obtained by polymerizing ethylene or higher alpha-olefins in the presence of a catalyst system comprising two or more metallocenes each having different propagation and termination rate constants and alumoxane.
TL;DR: In this paper, the development and the electrochemistry of low-rate laboratory prototype Li/S button cells is described. The cell consists of a lithium anode, a porous catalytic current collector which is loaded with sulfur, and an organic solvent containing lithium polysulfide.
Book•
01 Apr 1983TL;DR: The precise nature of these reactive C1 species is unknown at present and is the subject of lively debate as mentioned in this paper, and considerable diversity of current opinion will become apparent from the following account.
Abstract: The conversion of methanol to hydrocarbons is a remarkable reaction. The mechanism involves C-C bond formation from C1 fragments generated in the presence of certain acidic catalysts and reagents. The precise nature of these reactive C1 species is unknown at present and is the subject of lively debate. The considerable diversity of current opinion will become apparent from the following account.
TL;DR: It has been estimated that approximately 60% of all commercial chemicals are now obtained using processes involving heterogeneous catalysis as discussed by the authors, and over 90% of new large-scale plants employ heterogeneous catalysts.
Abstract: It has been estimated that approximately 60% of all commercial chemicals are now obtained using processes involving heterogeneous catalysis. In fact, over 90% of all new large-scale plants employ heterogeneous catalysts. This can be seen very clearly in Table 1, which lists the top 50 chemicals for the year 1980 [1].
TL;DR: In this article, a correlation between the nearest-neighbor distance and the oxygen reduction activity of various platinum alloys is reported, and it is proposed that the distance between nearest-nighbor Pt atoms on the surface of a supported catalyst is not ideal for dual site absorption of O2 or HO2.
Abstract: A correlation between the nearest-neighbor distance and the oxygen reduction activity of various platinum alloys is reported. It is proposed that the distance between nearest-neighbor Pt atoms on the surface of a supported catalyst is not ideal for dual site absorption of O2 or 'HO2' and that the introduction of foreign atoms which reduce the Pt nearest-neighbor spacing would result in higher oxygen reduction activity. This may allow the critical 0-0 bond interatomic distance and hence the optimum Pt-Pt separation for bond rupture to be determined from quantum chemical calculations. A composite analysis shows that the data on supported Pt alloys are consistent with Appleby's (1970) data on bulk metals with respect to specific activity, activation energy, preexponential factor, and percent d-band character.
TL;DR: In this paper, a model for the redispersion of Pt in oxygen is proposed and two surface oxides, α- and β-[PtO2]s, and two chloride-containing surface complexes are found and a comprehensive scheme of surface reactions is proposed.
TL;DR: In this paper, the authors investigated the kinetics of methane oxidation over palladium and platinum catalysts supported on a number of metal oxides using a pulse-flow microreactor technique.
TL;DR: Results suggest that albumin can influence, qualitatively and quantitatively, the metabolism of eicosanoids.
TL;DR: In this article, the reaction is realised by a partir d'un derive d'imidoiodobenzene obtenu par reaction du diisopropyl-2,5 benzenesulfonamide avec le diacetoxyiodobensene.
Abstract: La reaction est realisee a partir d'un derive d'imidoiodobenzene obtenu par reaction du diisopropyl-2,5 benzenesulfonamide avec le diacetoxyiodobenzene
TL;DR: In this paper, the activities of sulfided MoC, WC, CoC, NiC, Co-MoC, and Ni-WC catalysts for thiophene hydrodesulfurization and butene hydrogenation were studied using a flow microreactor operating at atmospheric pressure.
01 Mar 1983
TL;DR: Alginate gels have pores which are large enough to release catalytic acting enzymes out of the matrix, according to results of inverse steric exclusion chromatography.
Abstract: A method for the production of spherical alginate gels from few μm up to several mm diameter is described. Alginate beads with diameters from 0.5 to 3 mm are used to immobilize microorganisms as biocatalysts. Micro size alginate gels are used as column packing material for inverse steric exclusion chromatography to determine their pore sizes from dextran standards of known molecular weight. The results indicate that alginate gels have pores which are large enough to release catalytic acting enzymes out of the matrix.
TL;DR: In this paper, the acid-base properties of the surface of heterogeneous catalysts were analyzed using spectral properties of adsorbed molecules and the quantities through which the protonic (Bronsted), aprotic (Lewis), acidic and basic centres of the surfaces can be most easily characterised.
Abstract: The quantitative assessment of the acid–base properties of the surface of heterogeneous catalysts by i.r. spectral studies of adsorbed molecules is discussed. The quantities through which the protonic (Bronsted), aprotic (Lewis), acidic and basic centres of the surface can be most easily characterised are analysed. Reported methods of determining the number and strength of the surface centres are described. 135 references.
TL;DR: In this paper, the performance and availability of supported heteropoly acid under vapor phase conditions were studied through alkylation of benzene with ethylene, esterification of acetic acid with ethanol, and dehydration of 2-propanol as model reactions.
TL;DR: In this article, the specific activity for NO reduction was found to be sensitive to the nature of the catalyst pre-treatment, and the rate-limiting step in this model was assumed to be the dissociation of chemisorbed NO.
TL;DR: In this article, the reaction of N,N-diethylamino-tributyltin with aryl bromides in the presence of a catalytic amount of PdCl2(o-tolyl3P)2 gave N, N-deterministic derivatives, a new kind of amination different from ones through aryne or SRN1 mechanise
Abstract: The reaction of N,N-diethylamino-tributyltin with aryl bromides in the presence of a catalytic amount of PdCl2(o-tolyl3P)2 gave N,N-diethylaminobenzene derivatives. The reaction is a new kind of amination different from ones through aryne or SRN1 mechanise
TL;DR: In this article, the synthesis of (113-CsH13)((C6H5)zPCH2COO)Ni was reported, which proved to be an excellent one-component model catalyst for the oligomerization of ethylene as practiced in Shell's higher olefin process.
TL;DR: In this article, les conditions optimales de transformation d'isoxazolines-2 en β-hydroxycetones en utilisant un catalyseur Ni de Raney, l'acide borique, un melange 5/1 methanol/eau et l'hydrogene gazeux were determined.
Abstract: On determine les conditions optimales de transformation d'isoxazolines-2 en β-hydroxycetones en utilisant un catalyseur Ni de Raney, l'acide borique, un melange 5/1 methanol/eau et l'hydrogene gazeux