Research progress of Co and Mn-based catalysts for the oxidation of 5-hydroxymethylfurfural

Biomass is a renewable energy source abundantly available in nature. Their degradation by chemical or biological means produces various transition compounds. These transition compounds can be further transformed into valuable chemicals and biofuels that exhibit a wide range of applications and benefits. Recently, there has been a significant focus on this research area. Among the transition compounds, 5-hydroxymethylfurfural (HMF), derived from the degradation of hexose, is an important biomass-based platform compound that has hydroxymethyl and aldehyde functional groups in its molecular structure. This study reviews the recent progress in the transition metal-catalysed conversion of HMF using Co and Mn to generate high-value-added downstream products. Furthermore, the active components, the carbon supporter, the reaction mechanism, the oxidants and the reaction conditions of the catalysts are discussed in detail. The oxidation of HMF deserves further research as an important and complete value-added process for generating biomass-based valuable chemicals.