Preserving the aldehyde group of HMF in harsh reductive conditions is a challenging issue, because hydrogenation of C=O bond in HMF is more favourable than hydrodeoxygenation of C-OH, both kinetically and thermodynamically. A common strategy relies on an indirect molecular approach with the replacement of the hydroxy group by a good leaving group such as chloride, iodide, or formate prior to hydrogenation in mild conditions. Only very recently, Li et al. demonstrated for the first time the direct hydrodeoxygenation of HMF to 5-MF using an oxygen-defective Nb2O5 supported single atom noble metal catalysts. Unique reactivity was attributed to the limited adsorption modes available for the reactant at the metal-support interface and to the excellent cooperation of the Nb and the metal sites near at the interface. The use of Nb-based support was pointed out as essential for the selective activation of the C-OH bond at the Nb sites in the vicinity of the noble metal, while Au, Pd or Pt single atoms activated H2 and delivered H atoms for C-O bond scission. None of those sites were able to activate the C=O group. Shortly after, Dong et al. reported that anatase TiO2 supported Au-based catalysts are also capable of driving selectively the direct hydrodeoxygenation of HMF to 5-MF. Similarly, the selectivity was ascribed to the low level of adsorption of the reactants on the catalyst surface, with limited access to H species. According