the contribution of Lewis acid sites which would operate in cooperation
with the homogeneous weak Brønsted acidity brought by the aqueous acetic acid solution. According to
the literature, the two steps mechanism involving the xylose-xylulose isomerization over Lewis acid
sites and the successive Brønsted acid catalyzed cyclodehydration to furfural would be the prevailing
reaction pathway in the heterogeneous–homogenous catalytic system at 150 ◦C