Efficient Catalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid by Magnetic Laccase Catalyst.

2,5-Furandicarboxylic acid (FDCA) is a bio-based platform chemical for the production of polyethylene furanoate (PEF) and other valuable furanic chemicals. A magnetic laccase catalyst with (2,2,6,6-tetramethyl-piperidin-1-yl)oxyl (TEMPO) as the mediator has the remarkable capability of oxidizing 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). Under optimal reaction conditions, a quantitative yield (90.2 %) of FDCA with complete HMF conversion was obtained after 96 h of reaction. More importantly, the magnetic laccase catalyst exhibited good recyclability and stability, maintaining 84.8 % of its original activity following six reuse cycles. This is the first report on the efficient catalytic oxidation of HMF to FDCA by using an immobilized enzyme catalyst.