Acidic cesium salts of 12-tungstophosphoric acid as catalysts for the dehydration of xylose into furfural

Cesium salts of 12-tungstophosphoric acid, CsxH3−xPW12O40 (CsxPW), in the bulk form or supported on medium-pore MCM-41 (3.7 nm) or large-pore (9.6 nm) micelle-templated silicas are active solid acid catalysts for the cyclodehydration of xylose into furfural, in a toluene/water solvent system (T/W) or in dimethyl sulfoxide (DMSO). The catalytic results are comparable to those obtained using sulfuric acid, under similar reaction conditions. The initial activities increase in the order H3PW12O40 < Cs2.0PW < Cs2.5PW < silica-supported CsPW catalysts (15, 34 wt % PW). Higher HPA loadings, larger pore diameter of the parent silica support, and higher reaction temperatures lead to higher furfural yields. The stability and reusability of the MCM-41-supported CsPW is higher in DMSO than in T/W.

Graphical abstractCesium salts of 12-tungstophosphoric acid, CsxH3−xPW12O40, in the bulk form or supported on medium-pore MCM-41 (3.7 nm) or large-pore (9.6 nm) micelle-templated silicas are active solid acid catalysts for the cyclodehydration of xylose into furfural. The catalytic results are comparable to those obtained using sulfuric acid, under similar reaction conditions.Figure optionsDownload full-size imageDownload as PowerPoint slide