Showing papers in "Journal of Molecular Catalysis in 1985"

TL;DR: Preparation sous forme de monocristaux et determination par diffraction RX de la structure de [(C 6 H 13 ) 4 N] 3 {PO 4 [W(O)(O 2 ) 2 ] 4 }

TL;DR: Turnover rates for a number of reactions on several metals have been reproduced by different investigators using different preparations as mentioned in this paper, and agreement has been found between turnover rates on catalysts with 100% of metal exposed and on large single crystals.

TL;DR: In this article, a mechanism of oxidative dehydrogenation converting ethylbenzene to styrene on V2O5/MgO catalysts is suggested, and the nature and structure of the VVVIV active centres are discussed on the basis of physicochemical properties.

TL;DR: In this paper, a mechanism involving η3-allyl rhodium species is proposed to convert butadiene to pentanal with over 90% selectivity and less than 1% branched products.

TL;DR: In this article, the catalytic activity of the silicates in methanol conversion into hydrocarbons has been determined, and it was shown that Men+ fixation in tetrahedral oxygen surroundings in the silicate framework can be predicted on the basis of the Pauling criterion.

TL;DR: The SiO 2 -or Al 2 O 3 -attached Mo-monomer and -dimer catalysts with well-defined structures, prepared using the reaction between Mo(η 3 -C 3 H 5 ) 4 and the surface OH groups of silica or alumina and followed by chemical treatment, were found to be 10 -10 3 times more active than conventional Mo catalysts for propene metathesis over the temperature range 266 - 308 K as mentioned in this paper.

TL;DR: In this paper, a non-cage-like sequence of at least three coordination sites in the coordination sphere of the propagating species, is proposed to explain the experimental results.

TL;DR: In this article, the catalytic activity of cyclopentadienyl rhodium complexes was investigated in the cyclotrimerization reaction of alkynes to benzene derivatives, and the role played by the indenyl and fluorenyl ligands in determining the activity of the catalyst precursors I - IV.

TL;DR: In this paper, a review of catalysis by metal carbonyl clusters and cluster-derived metals in synthesis gas chemistry is presented, with special attention given to the selectivity of clusters in solution, heterogenized clusters, and cluster derived highly dispersed metals.

TL;DR: In this article, ZSM-5, boralites, offretite, HY, mordenite and omega were bonded with 20 wt% sepiolite into composite catalysts to oligomerize propylene in a fixed-bed, automated isothermal pilot unit operating at 30-50 atm.

TL;DR: The role played by both rhodium and alkoxide catalysts in the Guerbet reaction has been investigated in this article, showing a strong rate dependence upon the initial alkoxide concentration and indicated how the presence of water, a primary Guerbet product, leads to deactivation of the system.

TL;DR: A plant based on the CO process for acetic anhydride production has been built and is operated by Tennessee Eastman as mentioned in this paper, and a novel carbomethoxylation process for adipic acid manufacture and a two-phase catalyst system for propene hydroformylation, respectively.

TL;DR: In this paper, a 51:49 mixture of syn- and anti-7-methylbicyclo[2.2.1]hept-2-ene was subjected to a number of Ru-, Os-, Ir-, W- and Re-based catalysts, and the structures of the polymers and their hydrogenated analogues determined by 13C NMR spectroscopy.

TL;DR: In this article, a sample analysis of catalytic activity of the first hydration shell has been performed for the reaction CO 2 + H 2 O → H 2 CO 3 within the LCAO MO SCF ab initio approach.

TL;DR: In this article, the performance of ZSM-5 and Co-ThO2-ZSM-B catalysts was examined for the conversion of synthesis gas (H2/CO = 1) at 280 °C, 21 bar and WHSV = 0.77 g(g cat)−1 h−1 Thoria in amounts as low as 0.4 wt.%.

TL;DR: In this paper, the detection of surface species by chemical trapping is described and discussed and the results obtained by scavenging intermediates in CO-H 2 and CO 2 -H 2 reactions show the relevance of this method to the study of reaction mechanisms in heterogeneous catalysis.

TL;DR: Pillared-clays, when used to oligomerize propylene in a fixed bed isothermal reactor operating at 30 - 50 atm, appear to be less active than zeolite omega and an amorphous aluminosilicate (with 78% SiO 2 and 22% Al 2 O 3 ) catalyst, but have higher selectivity for gasoline production; formation of alkylated cyclopentane saturates was observed with these catalysts as discussed by the authors.

TL;DR: In this article, infrared spectroscopy and temperature-programmed techniques were used to examine and compare the interaction of CO/CO 2 /H 2 with three metal oxides, ZnO, TiO 2 and ZrO 2.

TL;DR: In this article, the reduction of nitrobenzene to aniline with CO + H2O is used as a model reaction to analyze the catalytic system formed by a Group VIII transition metal cluster and a nitrogen-containing chelating ligand.

TL;DR: In this article, it was shown that the catalytic activities of conventional heterogeneous metathesis catalysts are increased significantly by admixing minor amounts of elemental S, Si, Mg, Ba, Sn, Zn, Sb or W, and treating the admixtures at elevated temperature under an inert atmosphere.

TL;DR: In this paper, a linear correlation was found to exist between the concentration of the aqueous formate and the reaction rate in the presence of RuCl2(PPh3)3 and a quaternary ammonium salt.

TL;DR: In this paper, the results for weight increase, molar chlorine to titanium ratio, surface density of Ti and number of reactive OH groups are presented as a function of the dehydration temperature.

TL;DR: In this paper, a phase transfer reagent was used to enhance the reaction rate of cyclohexene in a two-phase water-dichloromethane system.

TL;DR: In this paper, various model clusters have been chosen to simulate the surfaces of phosphate catalysts (phosphoric acid, boron phosphate, aluminum phosphate and silicon phosphate) and semi-empirical CNDO/2 calculations have been performed, and the calculated electronic parameters are utilized to predict the surface acidbase characteristics of these catalysts and the effect of water adsorption.

TL;DR: In this paper, a kinetic study of the autoxidation of 2-mercaptoethanol using cobalt(II) phthalocyanine tetrasodium sulfonate attached to poly(vinylamine) as a catalyst was presented.

TL;DR: The best possible homogeneous catalysts must have carefully designed coordination spheres such that their acid/base or redox ground state properties are correctly tuned for the optimum expression of function, and such that the sites retain sufficient mobility to allow the catalyst atoms to pass easily along the reaction coordinates.