Catalytic combustion of methane over various perovskite-type oxides
1986; Elsevier BV; Volume: 26; Linguagem: Inglês
10.1016/s0166-9834(00)82556-7
ISSN1873-3867
AutoresH. ARAI, Takuya Yamada, Koichi Eguchi, Tetsuro Seiyama,
Tópico(s)Catalysts for Methane Reforming
ResumoCatalytic oxidation of methane was carried out over various perovskite-type oxides and compared with Pt/alumina catalyst. Of the oxides examined, partially cation-substituted LaFe, LaMn, and La-Co oxide systems showed high oxidation activities. Most excellent activity was attained by Sr-doped LaMnO3 (La0.6Sr0.4MnO3), which is almost as active as Pt/alumina catalyst at a conversion level below 80%. However, the increase in activity with temperature was significantly suppressed at a high conversion level. From kinetic analyses of reaction rate, the oxidation on Pt/alumina can be expressed by the Langmuir-Hinshelwood mechanism, in which the adsorbed oxygen plays a major role. On the other hand, weakly bonded adsorbed oxygen dominantly participates in the reaction on La-Mn oxides at low temperatures, whereas this oxygen desorbs with increasing temperature. The lattice oxygen becomes reactive at high temperatures after thermal desorption of adsorbed oxygen.
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