Dehydration of D-xylose to furfural using acid-functionalized MWCNTs catalysts*

Chompoopitch Termvidchakorn, Vorranutch Itthibenchapong, Siripit Songtawee, Busaya Chamnankid, Supawadee Namuangruk, Kajornsak Faungnawakij, Tawatchai Charinpanitkul, Radchadaporn Khunchit, Nanthiya Hansupaluk, Noriaki Sano and Hirofumi Hinode

Abstract

Acid-functionalized multi-wall carbon nanotubes (MWCNTs) catalysts were prepared by a wet chemical sonication with various acid solutions, i.e. H₂SO₄, H₃PO₄, HNO₃, and HCl. Sulfonic groups and carboxyl groups were detected on MWCNTs with H₂SO₄ treatment (s-MWCNTs), while only carboxyl groups were presented from other acid treatments. The catalytic dehydration of D-xylose into furfural was evaluated using a batch reactor at 170 °C for 3 h under N₂ pressure of 15 bar. The highest furfural selectivity was achieved around 57% by s-MWCNTs catalyst, suggesting a positive role of the sulfonic functionalized groups. The effect of Co species was related to their Lewis acid property resulting in the enhancement of xylose conversion with low selectivity to furfural product