Showing papers in "Applied Catalysis in 1984"

TL;DR: A geometrical model of sulphided unpromoted and promoted molybdenum or tungstensupported on alumina catalysts has been developed on the basis of two hypotheses which can be deduced from literature data: these are the presence of small patches of supported MoS2(WS2) and the importance of the edge sites located on these patches.

TL;DR: In this paper, the reducibility of platinum on γ-Al2O3- and TiO2 was studied with the aid of temperature programmed reduction, and the reduction peak temperature was found to be dependent on the temperature of the primary oxidation after impregnation and drying.

TL;DR: In this paper, a series of experiments in which a pyrolytic oil is contacted with a HZSM-5 zeolite catalyst was reported, and the results showed that the percentage of coke is mostly dependent on the flow rate of the oil whereas the proportion of unreacted tar is a function of temperature and flow rate.

TL;DR: The incorporation of phosphate ion into -A12O3 was studied by chromatographic techniques as mentioned in this paper, which showed a stabilizing effect of phosphate on the phase transition of alumina in the range 673-1323 K.

TL;DR: In this article, anatase-containing catalysts have been shown to have higher activity and selectivity in o-xylene oxidation, lower reduction degree of the catalyst in the stationary state of catalytic reaction, and lower dehydration/dehydrogenation ratio as compared with rutile-containing samples.

TL;DR: In this article, the reaction of phenol with methanol was carried out over five X-, six Y- and three ZSM-zeolites, in a fixed-bed continuous reactor at 250°C.

TL;DR: In this article, the effect of aging on the hydrogenation of a tail-end mixture (0.29 mol % C2H2, 0.44 mol % H2 balanced by C 2H4) has been investigated on Pd-black and on various Pd/Al2O3 catalysts.

TL;DR: In this paper, the phase composition of catalysts for hydrocarbon steam reforming and their resistance to coking was investigated in the presence in the catalysts of several crystallographic phases: the phase of solid solution NiO-MgO (rich in NiO), which facilitated coking, while the phase MgO-NiO, which inhibited coking.

TL;DR: In this paper, the influence of metal-support interactions on the dispersion, distribution, reducibility and catalytic activity for benzene hydrogenation of Ni/Si0 2 catalysts, prepared by impregnation or deposition-precipitation, was studied.

TL;DR: Two stages of decay of activity of the water-gas shift catalyst have been found by experiments, with fresh and ex-plant catalyst, in micro-reactor and semi-technical units as discussed by the authors.

TL;DR: In this article, the authors investigated the water-gas shift reaction in a microreactor and in a semi technical plant at pressures up to 30 bar over a commercial iron oxide/chromia catalyst.

TL;DR: Copper and silver were found to interact very differently with the oxidized iron catalyst as discussed by the authors, and the intimate contact between copper oxide and iron oxide and the facile reduction of copper oxide are responsible for the ability of copper to enhance the reduction of iron oxide.

TL;DR: The catalytic properties of vanadium oxide catalysts supported on TiO2 from Tioxide were strongly affected by phosphorus and potassium, present as impurities in the TiO 2 support as mentioned in this paper.

TL;DR: Raney nickel catalysts, prepared from well defined pure phases, have been characterised by bulk composition, total and nickel surface areas, structure, activity and sensitivity to sulfur compounds as discussed by the authors.

TL;DR: In this article, a review of efforts made to produce highly dispersed metal catalysts via the thermal decomposition of metal carbonyls is presented, and it is shown that on hydroxylated supports, the decomposition pattern of all metal carbonels follows a characteristic pattern.

TL;DR: The extent of aromatization and the distribution of aromatics in the conversions of methanol, ethanol, ethylene, propylene, butene-1, 1-hexene and cyclohexene on HZSM-5 zeolite are found to depend strongly on the extent of catalyst poisoning with pyridine, which causes not only a decrease in the stronger sites available for the reactions, but also leads to an increase in the diffusional resistance to the reaction species and the deactivation due to the deposition of hydrocarbon residues in the Zeolite channels as mentioned in this paper

TL;DR: In this article, a review of the control of the selectivity of mixed oxide catalysts for 1-butene oxidation is presented, in relation to the following three factors: role of oxygen partial pressure, doping with some special promoters of allylic oxidation (Te, Bi and Sb) and role of steam and ammonia.

TL;DR: In this paper, it was shown that the catalytic and chemisorptive properties of platinum towards benzene hydrogenation and adsorption of carbon monoxide in the linear form are still inhibited.

TL;DR: In this paper, the decomposition of FCC-related V and Ni compounds and the interaction of these compounds with FCC-catalyst are presented, and it is found that both with and without catalyst present Ni- and V-porphyrines decompose fully only after about 0.5 hours at 500°C at reactor conditions.

TL;DR: In this article, the activation energy for the water-gas shift reaction over an iron oxide/chromium oxide catalyst was calculated to be 129.4-2.1 kJ mol −1 from microreactor experiments, in good agreement with the value of 121.8 kJmol −1 deduced from semi-technical experiments with the same catalyst.

TL;DR: In this article, a flow system at 200°C, using montmorillonite intercalated by aluminium chlorohydroxyl complex (Al-mont) as a catalyst was investigated for disproportionation of 1,2,4,5-tetramethylbenzene and o-xylene.

TL;DR: In this article, the effects of promoters were systematically studied for various kinds and amounts of metal oxides, and it was found that the catalytic activity of copper is strongly affected by acid-base property of promoters, much as in the cases of many reactions catalyzed on metal oxide.

TL;DR: In this article, vanadium-phosphorous mixed oxides, specific catalysts for C 4. oxidation to maleic anhydride, were prepared using two methods as follows; i) method A, by reduction of V 2 O 5 with HCl after addition of H 3 PO 4 and ii) method B, by addition of NH 4 VO 3 to a solution containing H 3PO 4 and oxalic acid as reducing agents.

TL;DR: The effect of ammonium bicarbonate as a precipitant on the physical properties of activated alumina has been examined in this paper, where the resulting precipitate is shown to have the same properties as activated aluminium.

TL;DR: Vanadium-phosphorus mixed oxides, catalysts for C4 oxidation to maleic anhydride, were prepared in organic medium and tested in n-butane and butene-1 selective oxidation as mentioned in this paper.

TL;DR: In this article, the composition and deactivation effect of green oil on a Pd/A1203 catalyst (ICI 38-1) in the hydrogenation of a tail-end acetylene-ethylene mixture are discussed.

TL;DR: In this paper, the use of manganese nodules for catalytic and sorptive properties has been reviewed for both marine and fresh water sediments, and it is shown that they constitute a vast source of inexpensive catalysts and adsorbents.