Paramagnetic Ionic Liquid-Coated SiO2@Fe3O4 Nanoparticles - the Next Generation of Magnetically Recoverable Nanocatalysts Applied in the Glycolysis of PET

Abstract The functionalization of silica-coated, magnetic Fe3O4 nanoparticles, with an iron-containing ionic liquid, allows for the synthesis of a Fe3O4@SiO2@(mim)[FeCl4] system that can be employed as a magnetically recoverable nanocatalyst. Herein, we present the use of Fe3O4@SiO2@(mim)[FeCl4] for the glycolysis of PET into BHET under conventional heating. The catalyst achieved nearly 100% yield and selectivity over twelve consecutive reaction cycles at 180 °C and was efficiently recovered without tedious work-up or purification processes. Additional analyses revealed that the amount of catalyst lost after each cycle was negligible and no trace of Fe was found in the purified BHET product.