(617al) Synthesis of a Bi-Functional Catalyst and Application in One-Pot Conversion of Fructose into Oxygenated C9 and C15 Hydrocarbons
A bi-functional acid-base catalyst with silica-coated magnetic core was prepared through a series of functionalization steps. Amorphous silica layer was initially coated on crystalline iron oxide magnetic nanoparticles (Fe3O4 NPs) via solvothermal method. Two catalytic sites were then introduced on SiO2@Fe3O4 NPs via sequential silanization of two types of tri-ethoxy silanes. For the acidic active sites, the SiO2@Fe3O4 NPs was silanized with a thiol (-SH) terminated silane wherein its subsequent oxidation generated the sulfonic (SO3H) acid catalytic sites (SO3H-SiO2@Fe3O4). An epoxide terminated silane was then immobilized on SO3H-SiO2@Fe3O4 on which triazabicyclodecene (TBD) was attached via epoxide ring cleavage to generate the base catalytic sites, completing the bi-functional catalyst TBD-SO3H-SiO2@Fe3O4.
The prepared bi-functional catalyst and its precursors were characterized by XRD, HRTEM, EDAX, TGA, FT-IR and VSM analyses. Meanwhile, the catalytic performance of TBD-SO3H-SiO2@Fe3O4 was rigorously tested using fructose as substrate and its reusability for long-term use was also investigated. Results reveal that the developed catalyst can facilitate a cascade reaction involving dehydration of fructose and aldol condensation of furanic intermediate, 5-hydroxymethylfurfural (5-HMF) in one-pot. In particular, the prepared heterogeneous catalyst provided a synergistic catalytic activity for two-step chemical conversions of fructose into oxygenated precursors of C9 and C15alkanes. In this manner, tedious separation and purification steps of intermediate 5-HMF was avoided.
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education (No. 2009-0093816) and by the Ministry of Science, ICT & Future Planning (No. 2015R1C1A2A01054605).