Deoxydehydration Reactions of Galactaric Acid Using Imidazolium-based Ionic Liquids: Screening Study

Abstract

With worldwide caution for the depletion of petroleum resources, research for commodity chemicals derived from biomass has attracted many scientist and industries. In this regard, deoxydehydration(DODH) reaction, especially rhenium catalyzed DODH reaction, has been intensively studied due to its high efficiency of reducing oxygen contents from biomass to provide hydrocarbon chemicals. Although oxo-rhenium catalysts are known to be the most efficient in removing diol group to afford olefin, the high price of the rare metal catalyst causes hardship in industrialization of biomass-derived chemicals. In this thesis, as a novel method to provide economical and efficient process for DODH reaction, ionic liquid has been introduced as a reaction media to recycle commercial oxo-rhenium catalyst. The ionic liquid should successfully produce muconate from galactarate while being easily separated selectively dissolving rhenium catalyst. Various imidazolium-based ionic liquids have been screened to find the most appropriate ionic liquid. Among them, [C4MIm][TfO] showed the best efficiency affording 98% of the desired muconate, and the recovered ionic liquid showed moderate catalytic activity during reusability test.