The efficient oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid (FDCA) is achieved using the nano-CuO catalyst in a NaClO solution. The result demonstrates that the particle size of CuO can be effectively regulated by changing the calcination temperature, and the CuO catalyst with the smallest particle size exhibits superior oxidation activity and the maximum FDCA yield (96.0%).

The efficient oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is achieved using the nano-CuO catalyst in a NaClO solution. This study reveals that the particle size of the nano-CuO can be effectively regulated by adjusting the calcination temperature, thereby significantly improving the catalytic performance of HMF oxidation to the desired product FDCA. Notably, the CuO-100 catalyst with the smallest particle size exhibits superior HMF conversion and maximum FDCA yield (96.0%). Moreover, even with a reduced NaClO/HMF molar ratio of 7.3:1 to improve the utilization of NaClO, the 94.7% yield of FDCA is obtained on the CuO-100 catalyst.