Targeted acquisition furfural from xylose using sulfonic acid-functionalized organo-inorganic hybrid silica materials

Abstract

The catalytic dehydration of hemicellulose-derived xylose to furfural is a promising and appealing strategy for the effective utilization of biomass. A kind of sulfonic functionalized organic-inorganic hybrid silica materials (OIHMs-SO₃H), using tetraethyl orthosilicate (TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) as the starting precursors, were prepared via a sol-gel method which showed excellent catalytic performance for the dehydration of xylose to furfural. The microscopic structure, chemical composition and pore structure were ascertained by means of various characterization methods, such as SEM,FT-IR,TG-DTG,N₂ adsorption-desorption. 93.4 % conversion of xylose and 74.5 % selectivity of furfural was achieved under optimal conditions. More importantly, the catalysts displayed relatively high stability in five consecutive experimental cycles despite some acid sites covered by humus. In addition, the kinetics of reaction in this catalytic system were further investigated which demonstrated that the activation energy of xylose degradation (67.2 kJ/mol) was lower than that of xylose dehydration (122.8 kJ/mol) and furfural degradation (137.5 kJ/mol). All in all, this work provided an effective avenue for the synthesis of organic-inorganic hybrid silica materials applied to the conversion of xylose to furfural.