The excellent catalyst support of Al2O3 fibers with needle-like mullite structure and HMF oxidation into FDCA over CuO/Al2O3 fibers

Abstract Al2O3 fibers, especially with unique morphology and structure, are a fascinating class of ceramics that have been widely used as catalyst supports. In this work, smooth, porous and needle-like Al2O3 fibers are successfully prepared by electro-blowing spinning (EBS) method. Effects of calcination temperature, calcination rate and pore forming agent content (Polytetrafluoroethylene, PTFE) on the morphology and structure of Al2O3 fibers are systematically studied. Most importantly, Al2O3 fibers with different morphologies are particular suitable to be used as CuO supports for selective oxidation of 5-hydroxymethyl-2-furfural (HMF) to 2,5-furandicarboxylic acid (FDCA). Benefiting from the unique structure, FDCA synthesis over the needle-like CuO/Al2O3 fibers achieves 98.6% yield, which is much higher than the yields over smooth and porous CuO/Al2O3 fibers. Moreover, the fiber catalysts could be easily recovered and reused without the loss of its activity. It is anticipated that Al2O3 fibers with needle-like mullite will shed some light on the development of profiled ceramic fibers for various applications.