LAUSR

Trifunctional polyoxometalate (POM) decorating chitosan nanofibers (H5PMo10V2O40/chitosan nanofibers, abbreviated as HPMoV/CS-f) had been synthesized using electrospinning method, which realized highly efficient oxidation of 5-hydroxymethylfurfural (5-HMF) to 2,5-diformylfuran (DFF). Decorating chitosan nanofibers by POMs generated enhanced catalytic activity by emerging their unique individual properties of redox ability, Brønsted acidity, basic property, and nanofiber structure with higher surface area. As results, HPMoV/CS-f (25) (25, represented the POM amount) was found to be most active in aerobic oxidation of 5-HMF to give 94.1 % yield of DFF at 96.2 % conversion in dimethyl sulfoxide (DMSO) at 120 °C for 6 h, while 56.2 % yield of DFF at 95.0 % conversion was obtained in water system at 140 °C for 8 h. Most importance was that DFF could be produced in one-pot one-step to give 61.9 % and 31.4 % yields directly from fructose and glucose under the reaction conditions as 140 °C, 6 h in DMSO, which was due to the suitable balancing of Brønsted acidity and basicity of the trifunctional HPMoV/CS-f (25). Moreover, HPMoV/CS-f showed good stability and duration for being reused at least ten times without leaching of POMs from chitosan nanofibers.