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(guān)鍵字：Janus particles,TEMPO, Pickering interfacial catalyst, Alcohol oxidation, Biphasic reactions
論文來(lái)源：期刊
具體來(lái)源：Surfaces and Interfaces
發(fā)表時(shí)間：2024年
Pickering界面催化劑（Pickering interface catalyst, PICs）作為一種同時(shí)增強(qiáng)和催化液-液兩相反應(yīng)的有前景的解決方案而出現(xiàn)。在這項(xiàng)研究中，我們成功地合成了啞鈴形狀的Janus結(jié)構(gòu)聚合物納米顆粒，其中一側(cè)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(yīng)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(yōu)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(yōu)異的界面吸附能力使水/二氯甲烷Pickering乳狀液（乳狀液體積分?jǐn)?shù)＞90 %）具有2個(gè)月以上的強(qiáng)穩(wěn)定性，為液-液兩相反應(yīng)提供了高效的反應(yīng)平臺(tái)。結(jié)果表明，所構(gòu)建的皮克林乳液體系在靜態(tài)條件下能有效地催化肉桂醇氧化為肉桂醛。反應(yīng)1小時(shí)后，肉桂醇的轉(zhuǎn)化率達(dá)到97.1%，選擇性為99%，與攪拌強(qiáng)化雙相反應(yīng)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(yīng)的效率和可持續(xù)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(guó)家自然科學(xué)基金(資助號(hào):22178317、22109138)資助。