Alkylation of phenol/ tert ‑butyl alcohol on ionic liquid-immobilized SBA-15 with different pore sizes

Abstract

Mesoporous SBA-15 molecular sieves with different pore sizes were obtained using n-hexane as a micelle expander and NH4NO3 as structure adjuvant and used as support materials. The -SO3H immobilized environmentally Brӧnsted acidic ionic liquids were synthesized. Supported ionic liquids acid catalysts ([email protected] (5, 8, 12 nm)) were prepared by impregnation method and their physicochemical properties were characterized by FT-IR, TG-DSC, N2 physical adsorption, XRD, SEM and TEM. The catalytic activities of the synthesized acid catalysts were investigated by the alkylation of phenol with tert‑butyl alcohol (TBA). The effect of amount of IL supported, weight hour space velocity (WHSV), reactant mole ratio, reaction temperature, pore size of SBA-15 on the conversion of phenol and selectivity to products were investigated. Compared to [email protected] (5 nm) and [email protected] (12 nm), [email protected] (8 nm) exhibited the best phenol conversion up to 85.5% at 80 °C, suggesting that with the same content ionic liquid of catalysts, SBA-15 (8 nm) as support have remarkable catalytic activity and selectivity.