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 ironcontaining 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.

Crystal structure, magneto-structural correlation, thermal and electrical studies of an imidazolium halometallate molten salt: (trimim)[FeCl4]

“…As a result, these materials exhibit unusual anisotropic thermal expansion processes, which can be related to the ability of the organic moiety to present translational and reorientational phenomena that govern properties such as magnetism and solid-state ionic conduction. Moreover, from a technological point of view, due to their very interesting features in terms of Lewis-acidity, they are recently being applied as catalysts in reactions such as glycosidation, 18,19 Michael addition, 20 desulfurization 21 and CO 2 xation into cyclic carbonates, 22 among others.…”

Strategic Possibility Routes of Recycled PET

“…Furthermore, acidic ionic liquids’ application as dual-purpose catalysts simultaneously performs as a Lewis acid and nucleophile. It shows higher activity and selectivity than those used simple metal salts or solely organic ionic liquids [ 120 , 121 , 122 ]. Furthermore, the PET recycling by ionic liquid has several advantages: the extensive range broad of compound selection combined with anion and cation, non–volatility, thermal, electrochemical and low flammability [ 123 , 124 , 125 , 126 ].…”

Chemical recycling ofPET: A stepping‐stone toward sustainability

“…Cano et al 158 conducted glycolysis of PET utilizing paramagnetic ionic liquid‐coated SiO 2 @Fe 3 O 4 nanoparticles which was synthesized upon a four‐stage procedure and eventually transformed into a bifunctional Fe 3 O 4 @SiO 2 @(methylimidazolium)[FeCl 4 ]. This bifunctional nanocatalyst not only reached a high yield of BHET at 180°C but also demonstrated exiting reclaiming attitude and could be easily recovered with an external magnetic field.…”