Assembly of Multiple Components in a Hybrid Microcapsule: Designing a Magnetically Separable Pd Catalyst for Selective Hydrogenation

Abstract

In analogy to the role of long-chain polyamines in biosilicification, poly-L-lysine facilitates the assembly of nanocomponents to design multifunctional microcapsule structures. The method is demonstrated by the fabrication of a magnetically separable catalyst that accommodates Pd nanoparticles (NPs) as active catalyst, Fe3O4 NPs as magnetic component for easy recovery of the catalyst, and silica NPs to impart stability and selectivity to the catalyst. In addition, polyamines embedded inside the microcapsule prevent the agglomeration of Pd NPs and thus result in efficient catalytic activity in hydrogenation reactions, and the hydrophilic silica surface results in selectivity in reactions depending on the polarity of substrates.

Controlled Assembly of a Ternary‐Component Photocatalyst: Illustrating the Importance of Interfacial‐Integration of Ag‐ZnO‐rGO in Visible‐Light‐Induced Catalytic Activity

“…It involves hydrolysis of the zinc‐amine complex followed by condensation to produce Zn‐O−Zn linkages. The polyamine has a similar role as has been proposed in the biomineralization of diatoms . According to the mechanism, the polyamines bring the mineral pecusrsor species in close proximity to each other to allow their interaction forming ZnO structures.…”

“…As known in certain biomineralization processes like biosilcification of Diatoms, there are specific proteins containing polyamines and related polypeptides, which are the key for formation of their shell architecture under environmentally benign conditions. They play multiple functions to mineralize and assemble inorganic nanomaterials creating intricately designed hierarchical structures . In the present work, our approach is to exploit the role of polyamines in assembling multi‐functional units with desirable properties.…”

Magnetic Nanoparticle Composites: Synergistic Effects and Applications

“…The final composites were used as magnetically separable catalysts for selective hydrogenations. [ 315 ] In a different approach, Withania coagulans leaf extract was used as a reducing and stabilizing agent for the green two‐step synthesis of Pd/RGO/Fe 3 O 4 nanocomposites. The 4‐NP reduction catalysis was investigated using these composites.…”

“Naked” Magnetically Recyclable Mesoporous Au–γ‐Fe2O3 Nanocrystal Clusters: A Highly Integrated Catalyst System

“…Noble metal–Fe 3 O 4 nanocomposites have attracted much research interest because they can easily be recovered from reaction mixtures by applying an external magnet, as opposed to most other supported catalysts which require centrifugation . A variety of Fe 3 O 4 @noble metal core–shell nanocomposites and noble metal–Fe 3 O 4 nanocomposites have been developed in attempts to combine the advantages of noble metal catalysis and Fe 3 O 4 magnetism. In the synthesis of noble metal NPs and NP‐containing nanocomposites, organic capping agents such as citrate ions are introduced to stabilize the noble metal NPs against aggregation.…”