Showing papers in "Catalysis Today in 1987"

TL;DR: In this article, the same phase (vanadyl pyrophosphate) seems to be involved in the synthesis of butene and butane to maleic anhydride, and the methods of preparation determine the kind of redox system which is involved and how the various crystalline forms of VOPO 4 account for different reactivities observed.

TL;DR: The catalytic properties of PtHY, PtHZSM5 and PtH mordenite catalysts are controlled by the number of their acid sites (n A, number of acid sites on which the adsorption heat of NH 3 is greater than 100 kJ mol −1 ) and their hydrogenating sites ( n Pt ).

TL;DR: In this article, the advantages and limitations of using zeolite catalysts in hydroprocessing are discussed, and some challenges for catalytic research in this field are discussed: it is envisaged that zeolate catalyst design will figure significantly in the development of new, advanced process technology in the future.

TL;DR: In this article, the kinetics of hydroisomerization and hydrocracking of n-octane, n-decane and n-dodecane were studied on a Pt/US-Y zeolite at 130 − 250°C, 5 − 100 bar total pressure and molar hydrogen to hydrocarbon ratios from 10 to 150.

TL;DR: In this article, the authors considered three aspects of the title reaction: (1) control of catalyst morphology, (2) imparting catalyst attrition resistance, and (3) advantages of separating the redox steps.

TL;DR: In this article, preliminary results for the oxidative coupling of methane to give ethane/ethylene mixtures over a series of different catalyst formulations were reported; the temperature range studied is 650-850°C.

TL;DR: In this article, a coprecipitation-based coprocessor was used for the ammoxidation of toluene, p-and m-xylene and o-chlorotoluene.

TL;DR: In this article, preliminary results on the oxidation of methanol to methyl formate over coprecipitated V -Ti oxide catalysts calcined at 700 °C are reported.

TL;DR: In this paper, a detailed composition of the isomerization and hydrocracking products obtained in the reaction of 2-, 3-, 4- and 5-methylnonane, 2,6- and 3,5-dimethyloctane and 2,4, 6-and 3,3-5-trimethylheptane over Pt/USY using a continuous flow reactor and on-line high-resolution gas chromatography is reported.

TL;DR: In this article, a systematic kinetic study of the formation of three main products, propene, acetone and methacrylic acid, has been performed, and the results are explained in terms of a steady-state mechanism of the oxidised sites.

TL;DR: In this article, the effect of hydrogen partial pressure on the performance of distillate hydrocracking is investigated from both thermodynamic and kinetic standpoints, and the authors demonstrate that hydrogen pressure is a key parameter for both mild and total conversion.

TL;DR: In this paper, a look at today's Maleic Anhydride (MA) economic picture is presented, in which the authors discuss the different possible routes to MA, report figures and trends on feedstock and product prices, and capacity and product demand.

TL;DR: The production of maleic anhydride using n-butane feedstock in fixed bed reactors is the only technology that is used commercially in the USA today as discussed by the authors, and this technology is also practiced in other parts of the world to a lesser extent.

TL;DR: In this paper, the properties of mechanical oxide mixtures were studied in two reactions: N-ethyl formamide dehydration and isobutylene oxidation, and an interpretation of the results obtained was proposed on the basis of the remote control concept and an hypothesis about the junction between two cooperating phases.

TL;DR: In this article, the role of metal peroxides as intermediates in catalytic oxidations involving H 2 O 2 and ROOH as the oxygen source is studied through the stoichiometric oxidizing properties of the isolated d o metal peroxideidic complexes, and complete elucidation of the mechanism of the Halcon epoxidation process has been made possible by studying the reactivity of the complexes VO(OPhsal)(OOtBu) towards olefins.

TL;DR: In this paper, surface potential measurements have been performed to determine the nature of the oxygen species involved during the methane oxidation, and the results show that the catalyst is more oxidized in the case of O2 than it is when N2O is used.

TL;DR: In this article, an amorphous phase (V 5+ ) and a crystallized (VO) 2 P 2 O 7 (V 4+ ) were used for n-butane oxidation to maleic anhydride.

TL;DR: In this article, structural criteria already elaborated to account for the synergetic interfacial effects exhibited by the catalyst V2O5/TiO2 anatase have been used to find a new support for the catalyst TiO2(B), and the structural model was verified by taking into account the real external morphology of the support (habit and mean size of the crystallites).

TL;DR: In this paper, a previously proposed model of catalysis as a resonance effect was used to derive an expression for the isocatalytic temperature, which is characteristic for systems showing a "compensation effect" between the preexponential factor and the energy of activation.

TL;DR: In this paper, the activation of toluene, p-methoxytoluene and p-terbutyltolluene has been examined on several mixed oxide systems, based on molybdates, telluromolybdate and vanadia-titania catalysts.

TL;DR: In this article, the selectivity in maleic anhydride formation from n-butane in different reagent conditions and on (VO) 2 P 2 O 7 catalysts with different rates of oxidation of vanadium was studied.

TL;DR: In this article, the influence of the pretreatment of silver catalysts on their catalytic activity was studied with chemisorption experiments, TPD measurements and electron microscopy.

TL;DR: In this paper, the sensitivity of partial oxidation reactions to the structure of the metallic oxides has been recently demonstrated and the conditions of preparations and activation of a catalyst, the synergy effects observed in complex oxides, and the role of a support have all been reconsidered with new eyes.

TL;DR: In this article, the influence of the partial pressure of oxygen, pulse number and temperature on the catalytic epoxidation and degradation of propylene by dioxygen over a promoted unsupported silver catalyst at 638 K was studied by pulse technique.