title: A novel nanoscale catalyst system composed of nanosized Pd catalysts immobilized on Fe(3)O(4)@SiO(2)-PAMAM.
abstract: This study reports the syntheses of Fe(3)O(4)@SiO(2)-Gn-PAMAM-Pd(0) composites and their applications as magnetically recoverable catalysts for the hydrogenation of allyl alcohol. The controlled growth of polyamidoamine (PAMAM) dendrimers with different generations on Fe(3)O(4)@SiO(2) surfaces was monitored by FT-IR spectra. Subsequently, Pd nanoparticles with diameters of about 2.5 nm were stabilized homogeneously on the surface of Fe(3)O(4)@SiO(2)-Gn-PAMAM (n = 1-4), investigated by thermogravimetry (TG) and transmission electron microscopy (TEM) measurements. The Fe(3)O(4)@SiO(2)-Gn-PAMAM-Pd(0) have high catalytic activity for the hydrogenation of allyl alcohol and the rate of the reaction can be controlled by changing the generation of PAMAM. In particular, the composites made of superparamagnetic Fe(3)O(4) nanocrystals with diameters of about 10 nm are very suitable as catalyst supports for catalyst separation under a relatively low external magnetic field and catalyst re-dispersion after removing the external magnetic field.
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, People's Republic of China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Jiang
authors.forename: Jinhua
authors.initials: J
authors.lastname: Jiang
authors.forename: Qiuming
authors.initials: Q
authors.lastname: Gao
authors.forename: Meiling
authors.initials: M
authors.lastname: Ruan
authors.forename: Himei
authors.initials: H
authors.lastname: Yu
authors.forename: Lingjun
authors.initials: L
authors.lastname: Qi