Activation of formyl C?H and hydroxyl O?H bonds in HMF by the CuO(111) and Co3O4(110) surfaces: A DFT study

초록

Concerns about the non-renewability of fossil fuels and environmental pollution have led to the exploration of alternatives to fossil hydrocarbon resources to supply chemicals and energy. 5-Hydroxymethylfurfural (HMF) is considered to be a key bio-renewable platform molecule and is one of the ten most important platform chemicals listed by U.S. Department of Energy. The use of appropriate oxidants and a heterogeneous catalyst is quite advantageous for converting HMF into FDCA. In this work, density functional theory calculations with on-site Coulomb repulsion U terms were carried out to investigate the 5-hydroxymethylfurfural (HMF) adsorption on the CuO(111) and Co3O4(110) surfaces. The adsorption energy depends on both the coordination type of surface oxygen to which the hydrogen binds and the possible formation of H-bond involving hydroxyl and formyl groups on the adsorbed HMF. Also, the hydroxyl O?H bond breaking is very easy and is likely to be the first step in HMF oxidation, and then the OH insertion reaction to produce 2,5-furandicarboxylic acid (FDCA).