S. Ponce et al., Surface properties and catalytic performance in methane combustion of Sr-substituted lanthanum manganites, APP CATAL B, 24(3-4), 2000, pp. 193-205
Citations number
42
Categorie Soggetti
Physical Chemistry/Chemical Physics","Environmental Engineering & Energy
Perovskite type La1-xSrxMnO3 (x = 0-0.5) oxides were prepared by the amorph
ous citrate process, characterised by X-ray diffraction, oxygen desorption,
temperature-programmed reduction, infrared and X-ray photoelectron spectro
scopic techniques, and tested for methane combustion within the 473-1073 K
temperature range. Since catalyst activity was found to depend strongly on
BET areas and to a lesser extent, on the degree of substitution (x), intrin
sic activities were computed for La1-xSrxMnO3 catalyst series. Among the co
mpositions investigated, the degree of substitution x = 0.2 showed the high
est intrinsic activity within the temperatures explored. Characterisation t
echniques made possible to correlate catalytic performance with the structu
ral characteristics of the oxides. The stability of Mn4+ is probably the mo
st important parameter, but excess of oxygen and atomic surface composition
should also be taken into account. (C)2000 Elsevier Science B.V. All right
s reserved.