Silver-exchanged heteropolyacid catalyst (Ag1H2PW): An efficient heterogeneous catalyst for the synthesis of 5-ethoxymethylfurfural from 5-hydroxymethylfurfural and fructose

Three kinds of silver-exchanged phosphotungstic acid catalysts were prepared and used for the synthesis of potential biofuel 5-ethoxymethylfurfural (EMF). It was found that the partially silver exchanged phosphotungstic acid (Ag 1 H 2 PW) showed the best catalytic activity among silver exchanged phosphotungstic acids prepared. The highest EMF yield of 88.7% was obtained from 5-hydroxymethylfurfural (HMF) at 100   °C after 10   h. Furthermore, Ag 1 H 2 PW also showed high catalytic activity for the one-pot conversion of fructose into EMF with a yield of 69.5%. In addition, Ag 1 H 2 PW could be reused several times without a significant loss of its catalytic activity.