Journal ArticleDOI
Study of nickel-molybdenum-.gamma.-aluminum oxide catalysts by x-ray photoelectron and Raman spectroscopy. Comparison with cobalt-molybdenum-.gamma.-aluminum oxide catalysts
Reads0
Chats0
TLDR
Several series of nickel (or Co) molybdenum oxide catalysts supported on X-ray photoelectron and Raman spectroscopy have been studied by as discussed by the authors, where the combination of these two techniques is a complementary approach to the alumina coverage, the nature of the deposited species, and the interaction between these species.Abstract:
Several series of nickel (or Co) molybdenum oxide catalysts supported on ..gamma..-Al/sub 2/O/sub 3/ have been studied by X-ray photoelectron and Raman spectroscopy. The combination of these two techniques is a complementary approach to the alumina coverage, the nature of the deposited species, and the interaction between these species. In particular, the characteristics of the monolayer coverage by the nickel species appear somewhat different from cobalt in systems without molybdenum. When molybdenum is present, formation of a phase similar to (a) NiMoO/sub 4/ is observed. No bulk NiO or Ni(OH)/sub 2/ phases are detected. Comparison with Co-Mo or Ni-Mo-..gamma..-Al/sub 2/O/sub 3/ industrial catalysts is also presented.read more
Citations
More filters
Journal ArticleDOI
Raman and IR studies of surface metal oxide species on oxide supports: Supported metal oxide catalysts
TL;DR: In this article, the molecular structures of the surface metal oxide species are reflected in the terminal M=O and bridging M-O-M vibrations, which are typically obtained in Raman and IR characterization studies of supported metal oxide catalysts.
Journal ArticleDOI
A geometrical model of the active phase of hydrotreating catalysts
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.
Journal ArticleDOI
Comparison of reducibility and stability of alumina-supported Ni catalysts prepared by impregnation and co-precipitation
TL;DR: In this article, three Ni-Al 2 O 3 catalysts, with nickel loadings of 10-13 ¼ wt.%, were prepared by co-precipitation, impregnation on an in-house sol-gel derived alumina (Ni/sol-gel Al 2O 3 ), and impregnation on a commercial γ-al 2 O3 (Niγ-Al2 O 3 ), which were characterized by N 2 physisorption, H 2 chemisorptions, TPR, XRD, SEM and TEM.
Journal ArticleDOI
Raman spectroscopy of monolayer-type oxide catalysts: Supported Mo oxides
TL;DR: In this paper, a monolayer catalysts based on a structural model which assumed spreading of the active oxide over the support surface were investigated by a variety of techniques, conventional bulk sampling techniques as well as by surface-sensitive electron and ion spectroscopies, in an attempt to elucidate the nature of the catalyst surface species, and to study the coordination environment of active metal center(s).
Journal ArticleDOI
Investigation of Ni-based alumina-supported catalysts for the oxidative dehydrogenation of ethane to ethylene: structural characterization and reactivity studies
TL;DR: In this paper, the effect of nickel loading and the impact of the promoters on the performance of the materials are discussed in the light of a detailed physico-chemical characterization of the catalysts by N 2 adsorption.
Related Papers (5)
Raman and ultraviolet spectroscopic characterization of molybdena on alumina/catalysts
Studies of supported nickel catalysts by X-ray photoelectron and ion scattering spectroscopies
Milton. Wu,David M. Hercules +1 more