A magnetically recyclable superparamagnetic silica supported Pt nanocatalyst through a multi-carboxyl linker:
Laiming Li1, Youxin Li1, Jincong Yan1
1Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University Room 412-8, Building No. 24, 92 Weijin Road, Nankai District Tianjin 300037 China lyx@tju.edu.cn +86-22-2789-2820 +86-22-2789-2820.
Abstract:
To simplify separation procedures, improve the reusability and decrease the loss of Pt, two Pt catalysts anchored on superparamagnetic silica (Fe3O4@SiO2-EDTA@Pt and Fe3O4@SiO2-DTPA@Pt) were prepared for the first time. The stable magnetic properties made them easily recyclable using a magnet rather than filtration, decantation or centrifugation. After 12 catalytic runs for both 30-50 nm Pt catalysts, the yield of 1-heptylmethyldichlorosilane was still up to 90%. The average loss of Pt in each reaction was only 0.87% for Fe3O4@SiO2-EDTA@Pt and 0.66% for Fe3O4@SiO2-DTPA@Pt owing to the strong interaction between Pt and carboxyl. The unprecedented activity and selectivity of the two Pt nanoparticle catalysts were observed in the hydrosilylation of alkenes. The turnover number in the reaction between 1-hexene and methyldichlorosilane using 5 × 10-8 mol of the Pt approached 662 733 for Fe3O4@SiO2-EDTA@Pt and 579 947 for Fe3O4@SiO2-DTPA@Pt over 12 h. The corresponding hydrosilylation products in excellent yields were obtained when we employed a broad range of alkenes as substrates, including 5 isomerous hexenes and 14 important industry raw materials. Fe3O4@SiO2-DTPA@Pt showed a better activity. They have potential for catalyzing more reactions and replacing the current homogeneous Pt catalysts in industry.
More Related Videos
Related Concept Videos
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
01:13Olefin Metathesis Polymerization: Overview
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
02:13Reduction of Alkenes: Catalytic Hydrogenation
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...