Fundamental study of furfuryl alcohol dehydration reaction over molybdenum oxide catalyst

The conversion of furfuryl alcohol (FA) and selectivity towards dimers (C-9-C-10) and trimers (C-14-C-15) were investigated over molybdenum oxide (MoO3) catalyst. It was observed that FA conversion increased as an increase of reaction time. However, longer reaction time tended to limit the selectivity to dimers and trimers. Characterization data obtained from XRD, Raman, and XPS showed that after the reaction the terminal Mo=O bond was elongated and the oxidation state was changed from Mo-6 + to Mo5+. This was likely caused by the delocalization of extra electron to the Mo center during the activation of FA on MoO3 surface, instead of the formation of oxygen vacancy. After a proper regeneration process, the structure distortion caused by the elongation of Mo=O bond was fully restored, however, the oxidation state were only restored to Mo5+/6+. Recyclability test using regenerated MoO3 indicates Mo5+/6+ can be as active as Mo6+.