Synthesis and characterization of a supported ionic-liquid phase catalyst with a dual-mesoporous structure derived from poly(ionic liquids) and P123

Abstract

Herein, a novel strategy was proposed for the fabrication of hierarchical porous silica materials templated by a poly ionic liquid (PIL, a copolymer of 1-butyl-3-vinylimidazolium bromide and acrylamide) and P123 (PEO₂₀PPO₇₀PEO₂₀). The PIL acts as a co-solvent as well as a co-template in the system. The effects of the concentration of the PIL and pH on the morphology and structure of silica materials were systematically investigated. Hierarchical porous silica materials were characterized by X-ray diffraction, N₂ adsorption–desorption, transmission electron microscopy and Fourier transform infrared (FTIR) spectroscopy. Moreover, the results demonstrated that the porous silica materials were equipped with a dual-mesoporous channel structure and possessed a high surface area and large pore volumes up to 1274 m² g⁻¹ and 1.41 cm³ g⁻¹, respectively. Furthermore, a high-performance catalyst-based supported ionic liquid phase (SILP) was obtained by surface modification with the IL (1-(tri-ethoxy-silyl-propyl)-3-methylimidazolium chloride) of the carrier and anion exchange with HPW. Catalytic performances were investigated in the alkylation of styrene with o-xylene. Moreover, it was found that the as-synthesized catalysts showed high catalytic performance in terms of styrene conversion and selectivity to 1-phenyl-1-xylyl ethane (PXE). Specifically, the catalyst PIL-1.0g-2-IL-HPW showed excellent activities in both the yield (91.5%) and selectivity (96.8%) for this alkylation reaction.