257
(Wang et al. 2016c). The catalytic performances could be adjusted by choosing the
adequate reaction temperature. The post-addition of α-cyclodextrin improved the
catalytic activity by forming a complex with the 4-nitrophenol.
The complexation of guest molecules in the cyclodextrin cavity had also been
studied with polymers. For example, Li et al. (1994) had put forward the formation
of inclusion complexes called polypseudorotaxanes between poly(ethyleneglycol)
and α-cyclodextrin in the 1990s. In order to immobilize cyclodextrin along the polymer chain, a large number of polymers with stoppers, called polyrotaxanes, had
been reported. Thus, Wu et al. (2010) succeeded in stabilizing platinum nanoparticles in a water/ethylene glycol mixture, in the presence of a polyrotaxane in which
α-cyclodextrin was threated onto poly(ethyleneglycol) chains capped with triazoleβ- cyclodextrins (Fig. 5.21). The Pt nanoparticles were tested in the reduction of
4-nitrophenol by sodium borohydride. The authors assume that the high catalytic
activity came from the high density and high surface area of the nanoparticles that
had been adsorbed on the surface of the template.
5.3 Nanoparticles Immobilized on a Support in the Presence
of Cyclodextrin
Another strategy consists into the immobilization of metal nanoparticles on a support in order to improve the stability of these nanoheterogeneous catalysts.
Moreover, the interaction between the support and nanoparticles could also influence the catalytic activity and the selectivity of the reaction. Considering the state
of the art for nanoparticles immobilized on a support in the presence of cyclodextrin, two main strategies have been reported; whatever the nature of the support, it
Fig. 5.21 Polyrotaxane synthesized by Gao and co-workers for the deposition of platinum
nanoparticles in order to get nanowires. The catalytic activity is evaluated in the 4-nitrophenol
reduction using sodium borohydride. (Adapted from Wu et al. 2010)
5 Metal Nanoparticles and Cyclodextrins for Catalytic Applications
(Wang et al. 2016c). The catalytic performances could be adjusted by choosing the
adequate reaction temperature. The post-addition of α-cyclodextrin improved the
catalytic activity by forming a complex with the 4-nitrophenol.
The complexation of guest molecules in the cyclodextrin cavity had also been
studied with polymers. For example, Li et al. (1994) had put forward the formation
of inclusion complexes called polypseudorotaxanes between poly(ethyleneglycol)
and α-cyclodextrin in the 1990s. In order to immobilize cyclodextrin along the polymer chain, a large number of polymers with stoppers, called polyrotaxanes, had
been reported. Thus, Wu et al. (2010) succeeded in stabilizing platinum nanoparticles in a water/ethylene glycol mixture, in the presence of a polyrotaxane in which
α-cyclodextrin was threated onto poly(ethyleneglycol) chains capped with triazoleβ- cyclodextrins (Fig. 5.21). The Pt nanoparticles were tested in the reduction of
4-nitrophenol by sodium borohydride. The authors assume that the high catalytic
activity came from the high density and high surface area of the nanoparticles that
had been adsorbed on the surface of the template.
5.3 Nanoparticles Immobilized on a Support in the Presence
of Cyclodextrin
Another strategy consists into the immobilization of metal nanoparticles on a support in order to improve the stability of these nanoheterogeneous catalysts.
Moreover, the interaction between the support and nanoparticles could also influence the catalytic activity and the selectivity of the reaction. Considering the state
of the art for nanoparticles immobilized on a support in the presence of cyclodextrin, two main strategies have been reported; whatever the nature of the support, it
Fig. 5.21 Polyrotaxane synthesized by Gao and co-workers for the deposition of platinum
nanoparticles in order to get nanowires. The catalytic activity is evaluated in the 4-nitrophenol
reduction using sodium borohydride. (Adapted from Wu et al. 2010)
5 Metal Nanoparticles and Cyclodextrins for Catalytic Applications