Two birds with one stone: A magneto-optical dual-stimuli-responsive intelligent Pickering emulsion for efficient conversion of glucose to 5-hydroxymethylfurfural

Abstract

The efficient conversion of glucose to 5-hydroxymethylfurfural (HMF) is a critical process for maximizing the value of lignocellulosic biomass. However, the existing systems of binary solvent and ionic liquids (ILs) commonly employed for this conversion often encounter significant interphase mass transfer resistance and exhibit lower utilization efficiency of ILs. Herein, the study presents the precise fabrication of a novel Pickering interfacial catalyst, P(0.8[CL8]-[ILs]2-[SP])@SiO2@Fe3O4 with immobilized magneto-optical bi-sensitizer and Brønsted&di-superimposed-Lewis acid functionalized ILs (B-L-ILs), realized through surface-initiated reversible addition-fragmentation chain transfer polymerization. The construction of an intelligent Pickering emulsion with dual-stimuli-responsive properties was effectively accomplished by accurate manipulation under Vis-light radiation, utilizing P(0.8[CL8]-[ILs]2-[SP])@SiO2@Fe3O4. The presence of this emulsion significantly enhances interphase mass transfer in a binary solvent system, while the incorporation of B-L-ILs at interphase interfaces in Pickering emulsion greatly facilitates the efficient conversion of glucose to HMF. The Pickering interfacial catalyst demonstrates exceptional and unprecedented performance, as evidenced by its ability to achieve a glucose conversion rate of 96.3% and HMF yield of 86.7%. Various characterizations, experimental analyses, and kinetic studies synergistically confirm the efficient conversion of glucose to HMF in the Pickering emulsion. The effective control of Pickering demulsification can be intelligently achieved by simultaneously applying magnetic stimulation and UV-light irradiation, while its catalytic activity remains unaltered even after undergoing five consecutive cycles. This study presents a novel approach to enhance the efficiency of HMF production by combining a cutting-edge Pickering emulsion with B-L-ILs, thereby accomplishing two objectives simultaneously.