| Summary: | 碩士 === 國立成功大學 === 化學工程研究所 === 82 === The La-Sr-Co perovskite-type oxides prepared by the alkaline
coprecipitation method were employed to catalyze the oxidation
of toluene,p-xylene and their mixture.The activities of these
oxides for these oxidation reactions and the kinetics and me-
chanisms of these reactions were studied.The rate expressions
were also evaluated. The results reveal that the conversions of
toluene and p- xylene are over 90％ when the temperatures are
beyond 300 and 350℃,respectively.When the fractional
substitution of La by Sr is 0.3,the Co-series perovskites has
the highest activity be- cause the value of Co/(La+Sr) on the
surface is the largest. While the LaCoO3 catalyst has the
lowest activity because the quantity of α-oxygen adsorbed is
the smallest.When La0.7Sr0.3Co O3 is used as the catalyst,p-
xylene is easier to be oxidized than toluene and the oxidations
of both components are slight inhibited when the mixture of
toluene and p-xylene is oxidized. Both the oxidation reactions
of toluene and p-xylene can be represented by a dual-site
(different types) model.The expres- sions derived from this
model.
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