Oxidative transformation of methane over nickel catalysts supported on rare-earth metal oxides

Citation
A. Djaidja et al., Oxidative transformation of methane over nickel catalysts supported on rare-earth metal oxides, CATAL TODAY, 61(1-4), 2000, pp. 303-307
Citations number
22
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
CATALYSIS TODAY
ISSN journal
09205861 → ACNP
Volume
61
Issue
1-4
Year of publication
2000
Pages
303 - 307
Database
ISI
SICI code
0920-5861(20000810)61:1-4<303:OTOMON>2.0.ZU;2-G
Abstract
The oxidative transformation of methane over Ni catalysts supported on La, Sm and Ce oxides was investigated at atmospheric pressure, T=723-923 K and CH4/O-2=1-10. The BET surface areas were low (3-22 m(2) g(-1)) and decrease d strongly after reaction (down to 0.5 m(2) g(-1)). Carbonate species, Ni2O 3 and supported oxides were identified by XRD or IR spectroscopy studies in both the fresh and used catalysts. The Ni degrees phase was also probably formed as amorphous phase. The oxidative coupling of methane route passed t hrough a minimum as a function of the Ni percentage and was favored by the Ce or Sm oxide support, Li additive and low reaction temperature. High sele ctivities (60-90%) and good yields (about 15%) in C-2 hydrocarbons with low carbon balance (0-10%) were obtained at 823 K, La supported oxide, Ba addi tive and high reaction temperature favored the partial oxidation of methane . The obtained results were discussed in the light of the reducibility and acid-base properties of the catalysts. (C) 2000 Elsevier Science B.V. All r ights reserved.