| 摘 要： | The magnetism and surface behaviour of Pt-Dy/γ-Al_2O_3 catalysts were studied respectively bymeans of a Faraday magnetic balance and the method of carbon disulfide.The ferromagnetic impurity in thesupport,γ-Al_2O_3,at low temperature was corrected for the first time.The magnetic susceptibilities of the cat-alysts follow the sequence in different stage of preparation:χ_(uncalcined)<χ_(calcined)<χ_(reduced).The magnetic susceptibilities of the catalysts decrease as they adsorb hydrogen,cyclohexane or benzene.There is a correlation between the aromatization yield of cyclohexane or heptane on these catalysts and themagnetic susceptibility of the catalysts.Since addition of Dy increases the number of adsorption sites and therelevant proportions of weak adsorption sites,the abilities of sulfur-resistance and cyclohexanedehydrogenation are improved.In Pt-Dy/γ-A:_2O_3 catalysts,Dy improves the aromatization activity andstability of the catalyst and plays the role of the electron promoter.
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