Structural Design of Pd/SiO2@Ti-Containing Mesoporous Silica Core鈥揝hell Catalyst for Efficient One-Pot Oxidation Using in Situ Produced H2O2

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• 作者：Shusuke Okada ; Shohei Ikurumi ; Takashi Kamegawa ; Kohsuke Mori ; Hiromi Yamashita
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：July 12, 2012
• 年：2012
• 卷：116
• 期：27
• 页码：14360-14367
• 全文大小：592K
• 年卷期：v.116,no.27(July 12, 2012)
• ISSN：1932-7455

文摘

This study reports the importance of the structural design of heterogeneous catalysts for one-pot reaction. A series of core鈥搒hell catalysts were synthesized that consisted of SiO₂ core, Pd nanoparticles (NPs), and Ti-containing mesoporous silica (Ti-MS) shell with precise control of the Pd NPs positions, the mesopore diameter, and the thickness of the Ti-MS shell. The catalytic potentials were evaluated for one-pot oxidation reactions involving the direct synthesis of hydrogen peroxide (H₂O₂) from H₂ and O₂ gases by the Pd NPs and the subsequent oxidation reaction of sulfide by the isolated Ti^IV species using in situ produced H₂O₂ in the mesoporous silica. The precise architecture of the core鈥搒hell catalyst significantly enhanced the catalytic performance by a factor of 20, and the catalyst exhibited excellent activity and selectivity toward sulfoxide as compared to the commonly employed Pd-supported/Ti-zeolite (Pd/TS-1) catalyst. This result provides a new perspective of heterogeneous catalysts aimed at developing environmentally benign chemical processes.