Catalyst System for Hydrogenation Catalysis Based on Multiarm Hyperbranched Polymer Templated Metal (Au, Pt, Pd, Cu) Nanoparticles

Abstract

Abstract:With a hyperbranched poly(amidoamine) core and many water-soluble poly(ethylene glycol) monomethyl ether arms connected by pH-sensitive acylhydrazone bonds, multiarm hyperbranched polymer was used as nanoreactor and reductant to prepare metal nanoparticles endowed with intelligence and biocompatibility. The multiarm hyperbranched polymer encapsulated nanoparticles (NPs) showed excellent catalytic activity for hydrogenation, thus an excellent catalyst system for hydrogenation was established. The rate constants could reach as high as 3.48 L·s −1 ·m −2 , which can be attributed to the lack of surface passivation afforded by the multiarm hyperbranched polymer.

Role of Polymer Structures in Catalysis by Transition Metal and Metal Oxide Nanoparticle Composites

“…A similar nanoreactor architecture was explored by Shi et al 231 The star polymers with a hyperbranched poly(amido amine) (HPAMAM) core and water-soluble PEG arms were utilized to stabilize Au, Pd, Pt, and Cu NPs for hydrogenation reactions. The reduction of metal compounds to NPs was carried out by the polymer functional groups, in particular, pH sensitive acylhydrazone which was used to attach the PEG arms to the HPAMAM core.…”

“…A similar nanoreactor architecture was explored by Shi et al . The star polymers with a hyperbranched poly­(amido amine) (HPAMAM) core and water-soluble PEG arms were utilized to stabilize Au, Pd, Pt, and Cu NPs for hydrogenation reactions.…”

Nanocrystal Encapsulation, Release and Application Based on pH-Sensitive Covalent Dynamic Hyperbranched Polymers

“…The rate constant k app for Au/HPAMAM nanocomposites was 0.136 s −1 , as shown in Figure 11d. After being normalized to the surface area per unit volume, the rate constant k 1 was 1.56 L•s −1 •m −2 , which was a relatively high value for the reduction of PNP [50][51][52][53][54]. G4 or G6 PAMAM dendrimer often has steric crowding problems at the periphery, while HPAMAM with about three thousand molecular weight has little steric effect for PNP to access the surfaces of Au NPs.…”

Nitroarene hydrogenation catalysts based on Pd nanoparticles glued with PDA on inorganic supports: Multivariate Curve Resolution as an useful tool to compare the catalytic activity in multi-step reactions

“…Nanoparticles (NPs) of noble metals (Au, Ag, Pd, Pt) or 3d-metals immobilized on inorganic, organic, or hybrid supports, have been applied in the catalytic reduction of nitroarenes [1,2,13,[18][19][20][24][25][26][27][28][29][30][31]. The design of the morphology and organization of the catalysts in order to have more efficient active sites is of special relevance in the case of multicomponent catalysts, such as NPs incorporated on different supports.…”