结合两亲性结构的皮克林界面催化剂显著地扩展了绿色催化系统的可持续性。在这项工作中，我们提出了精确和精心设计的哑铃形状的双面结构聚合物纳米粒子，其单侧锚定钯簇(DB-JPP-Pd)作为静态氢化的Pickering界面催化剂。各叶的润湿性差异较大，使得哑铃形的DB-JPP-Pd具有明显的两亲性。两亲性Janus催化剂表现出优异的界面活性，界面张力从34.06±0.13大幅降低至20.54±0.31 mN/m，促进形成比本体PS-Pd催化剂更稳定的Pickering乳液，可以在反应过程中持续提供较大的界面面积，缩短分子传质距离。结果表明，在静态条件下，DB-JPP-Pd催化的硝基芳烃还原反应的归一化反应速率常数(knor)为3.39 min^-1·g^-1·L，是本体PS-Pd的56.5倍。所构建的Pickering界面催化(PIC)体系在3分钟内将硝基苯全部转化为苯胺，并对不同硝基芳烃的加氢具有良好的选择性。此外，乳液催化体系可以方便地连续运行10次。因此，这种独特的两亲哑铃型催化剂有效地发展了一种高效的静态双相催化体系。

Pickering interfacial catalysts incorporated with amphiphilic architecture significantly expand the sustainability of green catalysis systems. In this work, we present precise and well-designed dumbbell-shaped Janus-structured polymeric nanoparticles with one-side anchored palladium clusters (DB-JPP-Pd) as Pickering interfacial catalyst for static hydrogenations. The large wettability difference of each lobe renders the prominent amphiphilicity of the dumbbell-shaped DB-JPP-Pd. The amphiphilic Janus catalyst displays excellent interfacial activity and extensively reduces the interfacial tension from 34.06±0.13 to 20.54±0.31 mN/m, promoting the formation of a more stable Pickering emulsion than that of the bulk PS-Pd catalyst, which can continuously provide a large interfacial area and shorten the molecular mass transfer distance during the reaction process. As a result, the DB-JPP-Pd catalyzed nitroarene reduction reaction exhibits a normalized reaction rate constant (k_nor) of 3.39 min^-1·g^-1·L under static conditions, which is 56.5 times higher than that of bulk PS-Pd. The constructed Pickering interfacial catalysis (PIC) system converts all the nitrobenzene into aniline within three minutes and possesses excellent selectivity in hydrogenations of different nitro aromatics. In addition, the emulsion catalytic system was conveniently recycled for ten consecutive runs. Hence, this unique amphiphilic dumbbell-shaped catalyst effectively develops an efficient static biphasic catalysis system.

国家自然科学基金(资助号:22178317、22109138)资助。

https://doi.org/10.1016/j.jcat.2024.115444