Synthesis of furfural from xylose by heterogeneous and reusable nafion catalysts.

Nafion 117 has been proven as a robust and reusable heterogeneous catalyst for the dehydration of 9.1 % (w/w) xylose in dimethyl sulfoxide (DMSO) to yield 60 % furfural in 2 h at 150 °C. The catalytic high activity promoted shorter reaction times to limit the formation of side-products which otherwise would lead to decreased yields. Within the allowable operating temperature range of Nafion (125 to 175 °C), the reaction was kinetically controlled. In corroboration with AFM and SEM imaging, ATR-FTIR confirmed that the Nafion catalytic activity remained unchanged after 15 repeated uses. With excellent chemical and thermal stability under the conditions for xylose dehydration compared to existing solid acid catalysts, this reusable Nafion system could be a step towards the more economical production of furfural from renewable biomass, an intermediate chemical for the preparation of value-added chemicals.