Chemoselective hydrogenation of nitroarenes: Boosting nanoparticle efficiency by confinement within highly porous polymeric framework

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• 作者：Fernando Cá ; rdenas-Lizana ; Charline Berguerand ; Igor Yuranov ; Lioubov Kiwi-Minsker ; ^{lioubov.kiwi-minsker@epfl.ch}
• 关键词：Hyper cross-linked polystyrene ; Platinum ; Selective hydrogenation ; Functionalized nitroarene ; Tailored particle size ; Metal leaching
• 刊名：Journal of Catalysis
• 出版年：2013
• 出版时间：May, 2013
• 年：2013
• 卷：301
• 期：Complete
• 页码：103-111
• 全文大小：1343 K

文摘

We report for the first time 99.9 % yield of aminocompounds and high TOFs (up to 61 s^?1) in the liquid-phase hydrogenation of several para-substituted (-OH, -OCH₃, -CH₃, -H, -Br, -Cl, -COOH and -NO₂) nitroaromatics over quasi-monodispersed (ca. 3.3 nm from microscopy and CO chemisorption) Pt nanoparticles (NPs) confined within a hyper cross-linked polystyrene (HPS) polymeric matrix (uniform pore size ¡«4.6 nm; 1065 m² g^?1). Taking the selective hydrogenation of p-chloronitrobenzene as a model reaction, an antipathetic structure sensitivity (i.e. up to a 3-fold TOF greater over larger, 1.6 ¡ú 3.3 nm, Pt NPs) has been established. Moreover, a higher activity and amine selectivity were attained at elevated pressures (1 ¡ú 20 bar) irrespective of the support (i.e. active carbon, Al₂O₃ and HPS). Nonetheless, while Pt/HPS shows high stability without any activity/selectivity loss in repeated reaction runs, the state-of-the-art active carbon and alumina-supported Pt catalysts underwent a decrease in activity as a result of metal leaching. Our results demonstrate the potential of HPS as a suitable support for tailoring metal nanoparticle size and circumvent undesirable metal leaching.