Highly efficient trimerization of isobutene over silica supported chloroaluminate ionic liquid using C4 feed

A series of silica, glass and molecular sieves supported chloroaluminate ionic liquids (ILs) were prepared and their catalytic performance on the trimerization of isobutene based on C4 mixture was investigated. Interestingly, it was found that the carrier played a key role in the reaction route. Among these supported catalysts, silica supported chloroaluminate ionic liquid was highly efficient for the trimerization of isobutene. X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC) characterizations suggested that the synergy between Al2Cl7− anion and silica induced the catalytic activity for isobutene oligomerization due to the strong interaction between ILs and silanol group. The reaction conditions including loading amount, temperature, reactant concentration, and space velocity for the isobutene oligomerization were optimized. Ultimately, complete conversion of isobutene and 91.4% selectivity of trimers were obtained over the IL/silica (30 wt.%) catalyst at mild conditions. Moreover, catalyst stability and deactivation were preliminarily studied.

Silica supported chloroaluminate ionic liquids were prepared and used as acid catalysts for the trimerization of isobutene based on C4 feed. Under optimum conditions, total conversion of isobutene and 91% selectivity of trimers were obtained over the 30 wt.% chloroaluminate IL/silica catalyst.Figure optionsDownload high-quality image (143 K)Download as PowerPoint slideHighlights
► Silica supported chloroaluminate ionic liquids were developed for the trimerization of isobutene using C4 feed.
► Catalytic activity for isobutene oligomerization may derive from synergy between Al2Cl7− anion and silica.
► Under optimum conditions, total conversion of isobutene and 91% selectivity of trimers were obtained over the chloroaluminate IL/silica catalyst.