Noble Metal-Based Catalysts for Selective Oxidation of HMF to FDCA: Progress in Reaction Mechanism and Active Sites

Abstract

5-hydroxymethylfurfural (HMF) is oxidized to 2,5-furandicarboxylic acid (FDCA), which serves as a sustainable alternative to the petrochemical derivative terephthalic acid as a polyester monomer. Currently, noble metal catalysts that combine high HMF conversion rates with FDCA selectivity have become one of the mainstream catalytic systems for HMF oxidation. This paper summarizes and discusses the research progress on HMF oxidation to FDCA over different noble metal-based catalysts by combining DFT theoretical calculations, introducing various reaction pathways and mechanisms of HMF oxidation. It also analyzes the characteristics and electronic properties of metal active sites, geometric effects, metal–support interactions, and confinement effects, discussing and revealing the roles and activation mechanisms of different metal active sites, the structure of catalysts, active substances, metal valence states, activity, and the relationship between metal and the oxidation of C=O and OH groups. Finally, it presents views on the challenges and future development in the design of noble metal-based catalysts.