Enhanced catalytic properties of rhodium nanoparticles deposited on chemically modified SiO2 for hydrogenation of nitrile butadiene rubber

摘要

An efficient and recyclable catalyst was prepared by depositing rhodium nanoparticles (Rh NPs) on a SiO2 support with the surface modified by 3-aminopropyl-rimethoxysilane (APTS). The obtained catalyst, Rh((III))/ MSiO2, was extensively characterized by FTIR, SEM, XRD, XPS, BET, and ICP to demonstrate the incorporation of amine groups on the surface of the modified SiO2. The hydrogenation of acrylonitrile butadiene rubber (NBR) was used to evaluate the catalytic properties of Rh((III))/ MSiO2, and a 98.68% conversion and nearly 100% selectivity to C=C were obtained under optimum conditions (120 degrees C, 3.0 MPa H-2, 8h). A comparative study was made between Rh((III))/ MSiO2 and Rh((III))/ SiO2 in the hydrogenation of NBR, and Rh((III))/ MSiO2 showed higher activity and higher stability. The results indicated that the increase of the amount of deposited metal particles and the improvement of the adhesion of metal particles to the support are the reasons for the high performance of Rh((III))/ MSiO2. In addition, the Rh((III))/ MSiO2 could be easily recovered by centrifugation and reused 3 times with only a slight loss in activity and selectivity. Furthermore, this modified method can be extended to other heterogeneous catalyst systems to improve their activity, recyclability and stability.