Aerobic oxidation of 5-hydroxymethylfurfural (HMF) effectively catalyzed by a Ce0.8Bi0.2O2−δ supported Pt catalyst at room temperature
The oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) was efficiently catalyzed when Pt nanoparticles (NPs) were supported onto a Ce0.8Bi0.2O2−δ solid solution. 98% yield of FDCA was achieved within 30 min at room temperature and the catalyst was reused five times without much loss of FDCA selectivity. It is the first report on the oxidation of HMF, an alcohol and an aldehyde, effectively catalyzed by a ceria-based material supported Pt catalyst. The individual properties of the Pt NPs and the ceria-based support were retained and not affected after their combination. The superior oxygen activation ability of the Bi-doped ceria thoroughly changed the performance of the ceria supported Pt catalyst. Pt NPs were responsible for the formation of the Pt–alkoxide intermediate, followed by β-H elimination with the help of hydroxide ions. Bi-containing ceria accelerated the oxygen reduction process because of the presence of a large amount of oxygen vacancies and the cleavage of the peroxide intermediate promoted by bismuth. These specific functions were well incorporated during the catalytic oxidation cycle, leading to the generation of the highly efficient Pt/Ce0.8Bi0.2O2−δ catalyst for HMF oxidation at room temperature.