TEMPO immobilized polymericdumbbel: Assembly and catalysis at liquid-liquid interface
作者：Hao Zhang, Zhengyuan Tao, Ziqi Yu, Tiantian Zhu, Hanlin Rao, Badusha Mohamad Ali, Jianli Wang
關鍵字：Janus particles,TEMPO, Pickering interfacial catalyst, Alcohol oxidation, Biphasic reactions
論文來源：期刊
具體來源：Surfaces and Interfaces
發表時間：2024年
Pickering界面催化劑（Pickering interface catalyst, PICs）作為一種同時增強和催化液-液兩相反應的有前景的解決方案而出現。在這項研究中，我們成功地合成了啞鈴形狀的Janus結構聚合物納米顆粒，其中一側錨定咪唑-TEMPO（im-C4-TEMPO@JPP）作為醇氧化的Pickering界面催化劑，使用Anelli-Montanari反應體系。在Pickering乳液體系中，由于咪唑-TEMPO錨定葉的親水性，im-C4-TEMPO@JPPs顆粒聚集在W/O界面上，這使得聚合物Janus啞鈴具有優異的兩親性。此外，im-C4-TEMPO@JPPs顆粒使界面張力從27.82 mN/m降低到18.43 mN/m。im-C4-TEMPO@JPPs優異的界面吸附能力使水/二氯甲烷Pickering乳狀液（乳狀液體積分數＞90 %）具有2個月以上的強穩定性，為液-液兩相反應提供了高效的反應平臺。結果表明，所構建的皮克林乳液體系在靜態條件下能有效地催化肉桂醇氧化為肉桂醛。反應1小時后，肉桂醇的轉化率達到97.1%，選擇性為99%，與攪拌強化雙相反應基本相同。因此，這種新型PIC有效地提高了液-液兩相催化反應的效率和可持續性。
Pickering interfacial catalysts (PICs) have emerged as a promising solution for simultaneously enhancing and catalyzing liquid-liquid biphasic reactions. In this study, we successfully synthesized dumbbell-shaped Janus structured polymeric nanoparticles with one side anchored imidazolium-TEMPO (im-C4-TEMPO@JPP) as Pickering interfacial catalyst for the oxidation of alcohols using the Anelli-Montanari reaction system. In the Pickering emulsion system, the im-C4-TEMPO@JPPs particles are assembled at the W/O interface due to the hydrophilicity of imidazolium-TEMPO anchored lobe which enables excellent amphiphilic character of the polymeric Janus dumbbell. Moreover, the im-C4-TEMPO@JPPs particles reduce the interfacial tension from 27.82 to 18.43 mN/m. This excellent interfacial adsorption capacity of im-C4-TEMPO@JPPs strongly stabilizes the water/dichloromethane Pickering emulsion over two months (emulsion volume fraction >90 %), thus providing an efficient reaction platform for liquid-liquid biphasic reactions. As a result, the constructed Pickering emulsion system efficiently catalyzes the oxidation of cinnamyl alcohol to cinnamaldehyde under static conditions. After 1 hour of reaction, the conversion of cinnamyl alcohol achieved 97.1 % with a selectivity of 99 %, nearly the same level relative to stirring intensified biphasic reaction. Hence, this novel PIC effectively improves the efficiency and sustainability of liquid-liquid biphasic catalytic reactions.
國家自然科學基金(資助號:22178317、22109138)資助。