Showing papers on "Temperature-programmed reduction published in 1987"
TL;DR: In this paper, the titania supported vanadium oxide layers have been prepared and tested as catalysts for the selective catalytic reduction (SCR) of nitric oxide with ammonia.
154 citations
ARCO1
TL;DR: In this article, the authors reported that the temperature-programmed reduction traces of unsupported ceria show two peaks, which are associated with surface capping oxide ions and bulk ions, respectively, making it possible to determine the specific surface area of supported ceria.
129 citations
TL;DR: In this article, vanadyl triisobutoxide with surface hydroxyl groups of the catalysts were investigated with regard to their structural properties and their activity in selective catalytic reduction of nitric oxide with ammonia.
92 citations
TL;DR: In this article, the location of the promoter element in rhodium on alumina and silica catalysts promoted by vanadium oxide has been studied by various techniques, including temperature programmed reduction and diffuse reflectance infrared spectroscopy.
53 citations
TL;DR: In this paper, two 10% FeAl2O3 catalysts with supports of different surface areas were studied by means of an in situ combined temperature-programmed reduction (TPR)-Mossbauer spectroscopy technique.
40 citations
TL;DR: In this article, temperature-programmed reduction has been used to characterise unsupported Fe and Mn-promoted Fe catalysts containing 1-4% Mn, and their precursor oxides/hydroxides, which strongly imply that the surface of the Feo particles is substantially covered by a layer of MnO species which is complete at Mn concentrations of less than 1%.
34 citations
TL;DR: The interaction of unsupported silver with oxygen at atmospheric pressure and at temperatures between 100 and 600°C has been studied using temperature programmed reduction and desorption experiments with temperatures ranging up to 900°C as mentioned in this paper.
33 citations
TL;DR: In this article, the interaction of an unsupported silver catalyst which had been pretreated by hydrogen at various temperatures with oxygen at 210°C has been studied using Temperature Programmed Reduction (TPR) over a temperature range up to 900°C.
30 citations
TL;DR: In this paper, an experimental set-up is described for the characterization of organic sulfur-containing functional groups with a temperature programmed reduction method (TPR) and both a low sulfur and a high sulfur coal have been analyzed.
20 citations
TL;DR: In this paper, the reduction of EUROPT-1 in the "as-received" state was studied and the results were consistent with the concept that this material contains a disordered Pt oxide phase.
18 citations
TL;DR: In this paper, the formation of some surface sites and groups on a Co Mo/Al2O3 catalyst during its activation by reduction with hydrogen or by reductive sulphidation with mixture of hydrogen and hydrogen sulphide has been studied.
TL;DR: From magnetic susceptibility, temperature programmed reduction and ESR measurements, it was concluded that the Cu(II) has most probably disproportionated to Cu(I), Cu(III).
TL;DR: In this article, gas chromatographic studies on the thermal decomposition of 12-molybdophosphoric acid (PMA) and its salts with the cations K +, Ca 2+, Mn 2+ and Co 2+ are reported.
TL;DR: In this article, the size of the supported oxide crystallites has been found to be related to the different thermal pretreatment and to the nature of the support, and the presence of ionic Fe exchange with the support was determined in the case of the silica support.
TL;DR: In this paper, the rate of temperature increase of a CoMo/Al2O3 hydrorefining catalyst during its activation with a H2SH2N2 mixture affected its reducibility and activity.
TL;DR: In this paper, the preparation of sphere-shaped silica supported vanadium catalysts was carried out by using various techniques, such as wet impregnation, the so-called monolayer adsorption, which was developed at the Twente University of Technology (The Netherlands) and the homogeneous deposition precipitation, developed at State University of Utrecht.
Abstract: The preparation of sphere-shaped silica supported vanadium catalysts was carried out by using various techniques. The silica support was prepared by the sol-gel process, developed by KEMA. (change-para-here) After the sphere formation, drying and sintering steps, the spheres of controlled diameters can be impregnated and coated by existing techniques, such as: wet impregnation, the so-called monolayer adsorption, which was developed at the Twente University of Technology (The Netherlands) and the homogeneous deposition precipitation, developed at the State University of Utrecht. (change-para-here) The characterization of the catalysts was carried out by using various methods such as: activity measurements with a conventional fixed-bed reactor coupled with a mass spectrometer, temperature programmed reduction, scanning electron microscopy, X-ray fluorescence, BET-sorption and mercury-porosimetry.
TL;DR: In this paper, an iron-ruthenium catalysts supported on titania of differing surface areas have been prepared and characterised by in-situ 57 Fe Mossbauer spectroscopy and temperature programmed reduction techniques (TPR) for Fischer-Tropsch synthesis.
Abstract: Iron-ruthenium catalysts supported on titania of differing surface areas have been prepared and characterised by in-situ 57 Fe Mossbauer spectroscopy and temperature programmed reduction techniques (TPR) The results have shown that interactions between iron and titania supports are strongest when high surface area titania is used However, such interactions are weaker than those between iron and silica and between iron and aluminia The catalytic properties of these materials for Fischer-Tropsch synthesis have been evaluated in a microreactor system at 235°C and at 25 Kg/cm 2 pressure The incorporation of iron into titania-supported ruthenium catalysts has a significant influence on selectivity In contrast, the selectivities of less active silica-svpported catalysts are insensitive to the iron concentration
TL;DR: In this paper, the catalysts were investigated by temperature programmed reduction (TPR) and subsequently reduced in the temperature range 200-500°C and metal surface areas were measured via H2 and CO chemisorption.
Abstract: Nickel catalysts have been prepared by impregnation and precipitation methods on silica and charcoal. Metal loadings were in the range 1–40% w/w Ni on the support.
The catalysts were investigated by temperature programmed reduction (TPR) and subsequently reduced in the temperature range 200–500°C. Metal surface areas were measured via H2 and CO chemisorption and limited studies of the catalysts were carried out using X-ray photon spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM) to determine the chemical and physical state of the nickel after reduction. Reduced catalysts were employed for triglyceride (soya bean oil) hydrogenation (1 atmos H2, 160°C) in a stirred reactor (1000 rpm) and reaction rates (catalyst activity) and product distributions were determined.
Charcoal supported catalysts were active and zero valent nickel was detected after reduction. However, surface areas were variable, the performance of such catalysts being affected by pore effects, agglomeration and possibly nickel–charcoal interaction.
Silica supported precipitated catalysts were of relatively high activity and metal surface if methanol washed before activation and inactive (irreducible) if only water washed.
Although silica supported precipitated catalysts were more active per unit weight of metal than charcoal supported counterparts, they were less active per unit metal area and gave rise to greater trans-acid production. This may be due to triglyceride molecules excluding hydrogen from small nickel crystallites.