The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials , Shanghai Normal University , 100 Guilin Road , Shanghai 200234 , China.
Faculty of Chemical Engineering , Ho Chi Minh City University of Technology , 268 Ly Thuong Kiet Street, District 10 , Ho Chi Minh City , VN 84 , Vietnam.
ACS Appl Mater Interfaces. 2019 Nov 6;11(44):41238-41244. doi: 10.1021/acsami.9b11459. Epub 2019 Oct 25.
Metal nanoparticles have been recognized and widely explored as unique catalysts for carbon-carbon coupling reactions. However, due to their extreme tendency to agglomeration, the generation and stabilization of metal nanoparticles in a porous matrix is an important research field. Herein, novel mesoporous phenolic resin-supported palladium nanoparticles (Pd@NH-MPRNs) were prepared via direct anionic exchange followed by gentle reduction by using primary amine-functionalized ordered mesoporous phenolic resin as the support. The obtained Pd@NH-MPRN material still possessed large surface area and ordered two-dimensional hexagonal mesoporous structure. Meanwhile, uniform and well-dispersed palladium nanoparticles were formed in the mesoporous channels, which could be attributed to an efficient complexation and stabilization effect derived from the primary amine groups. As a result, it can promote Suzuki coupling of less activated aromatic bromides to various biaryls in water with high conversion and selectivity. This excellent performance was attributed to small particle sizes, ordered mesopores, and a hydrophobic pore surface, which resulted in the decreased diffusion limitation and the increased active site accessibility. It is noted that it is competitive with the best palladium catalysts known for water-medium Suzuki coupling reaction, and it can be reused at least seven times without significant reduction in the catalytic efficiency, showing a good recyclability. Therefore, this work provides a new potential platform for designing and fabricating robust ordered mesoporous-polymer-supported metal nanoparticles for various catalytic applications.
金属纳米粒子已被公认为独特的碳碳偶联反应催化剂，并得到了广泛的研究。然而，由于其极易团聚的特性，在多孔基质中生成和稳定金属纳米粒子是一个重要的研究领域。在此，我们通过直接阴离子交换，然后使用伯胺功能化的有序介孔酚醛树脂作为载体进行温和还原，制备了新型介孔酚醛树脂负载的钯纳米粒子（Pd@NH-MPRNs）。所得到的 Pd@NH-MPRN 材料仍具有大的表面积和有序的二维六方介孔结构。同时，均匀分散的钯纳米粒子形成在介孔通道中，这归因于伯胺基团的有效络合和稳定作用。结果表明，该材料在水中能够促进较少活化的芳基溴与各种联苯的 Suzuki 偶联反应，具有高转化率和选择性。这种优异的性能归因于小的颗粒尺寸、有序的介孔和疏水性的孔表面，从而降低了扩散限制并增加了活性位的可及性。值得注意的是，它在水相介质中的 Suzuki 偶联反应中与已知的最佳钯催化剂具有竞争力，并且可以至少重复使用七次而催化效率没有明显降低，显示出良好的可回收性。因此，这项工作为设计和制备用于各种催化应用的稳定有序介孔聚合物负载金属纳米粒子提供了一个新的潜在平台。
