Sulfonic acid functionalized silica coated magnetic nanoparticle catalysts

INOR 501

Christopher S. Gill, christopher.gill@chbe.gatech.edu and Christopher W. Jones, cjones@chbe.gatech.edu. School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr, Atlanta, GA 30332
Magnetic nanoparticles (MNPs) have received increasing attention in recent years due to their unique properties. These properties (ability to be dispersed into a solvent, high thermal stability, high surface area, facile recovery, and capacity for surface functionalizations) can be exploited when utilizing the MNPs as catalyst supports.

This work describes the synthesis, characterization, and kinetic activity of four different sulfonic acid functionalized hybrid organic/inorganic catalysts. CoFe2O4 MNPs were synthesized using a microemulsion method and subsequently coated with a 10 nm thick silica shell. The silica coating step was observed to be necessary to prevent adverse reactions between the surface chemistry and the metal oxide core. Sulfonic acid sites were then post-grafted to the silica coated MNPs and characterized via TEM, XRD, FT-IR, TGA, and titrations. In test reactions, the magnetic, solid acid catalysts were observed to be easily recoverable and exhibit minimal loss in activity upon recycle.