Pd-Dispersed CeO₂ Catalyst Prepared from Dealloying the Pd–Ce–Al Ternary Amorphous Alloy Used for Oxidation Reaction

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The relationship between preparation method and the catalytic activity as well as reusability for Pd–CeO₂ catalyst was investigated. Pd-dispersed CeO₂ prepared from dealloying in NaOH aqueous solution of a Pd–Ce–Al ternary amorphous alloy as a precursor. The dealloying proceeded by active dissolution of Al and Ce to form sodium aluminate ion, Na[Al(OH₄)](aq), and CeO₂ particles, respectively. At the same time, Pd acting as cathode resulted in directly to be metallic nailed-particles exposing partly from the matrices of the CeO₂ particles. Its catalytic activity and reusability as a function of its surface area of exposed-Pd as well as sample surface area were investigated, compared with those of Pd-supported CeO₂ which was prepared by conventional liquid phase reduction. Pd-dispersed CeO₂ was higher in exposed Pd surface area than Pd-supported CeO₂ despite its lower sample surface area. It is likely that the nailed Pd on the CeO₂ prevents themselves from aggregation during sample preparation and reusability study. As a result, in the oxidation reaction of methyl benzyl alcohol, Pd-dispersed CeO₂ showed higher catalytic activity and reusability than Pd-supported CeO₂. The oxidation reaction of methyl benzyl alcohol is a measure of the oxidative decomposition reaction of harmful substances. Pd-dispersed CeO₂ is expected to be widely used for the oxidative decomposition reaction of harmful substances.