Palladium Nanoparticles Encapsulated in Hollow Titanosilicate Spheres as an Ideal Nanoreactor for One-pot Oxidation.

One-pot reaction involving Pd-catalyzed H ₂ O ₂ production from H ₂ and O ₂ and Ti-catalyzed successive oxidation with H ₂ O ₂ in a single reaction vessel is an alluring strategy for the synthesis of targeted chemicals in terms of sustainability and economic competitiveness. In this study, a yolk-shell nanostructured catalyst, consisting of Pd nanoparticles (NPs) with core diameter ca. 4.0 nm and a porous titanosilicate shell of ca. 15 nm thickness, was fabricated by using an oil-in-water (O/W) microemulsion-based interfacial self-assembly approach. Compared with prototype titanosilicate-supported Pd NP catalysts and core-shell structured analogues, the yolk-shell nanostructured catalyst exhibited superior catalytic efficiency in the one-pot oxidation reaction of sulfides with 83 % H ₂ O ₂ utilization efficiency, because of the productive effect of the titanosilicate shell in limiting the diffusion of H ₂ O ₂ generated in situ over the encapsulated Pd NPs and the efficient access of the H ₂ O ₂ to the neighboring active Ti sites. This study provides promising avenues for the development of multifunctional nanostructured catalysts that are useful for one-pot reactions.
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