Direct conversion of glucose to 5-hydroxymethylfurfural over niobium oxide/phosphate-carbon composites derived from hydrothermal carbonization of cyclodextrins

Walid Hamza Saadaoui (1) , Cécile Machut (1) , Sébastien Rio (1) , Sandra Bigot (2) , Vincent Wiatz (2) , Eric Monflier (1) , Anne Ponchel (1)

1 UCCS Équipe Catalyse Supramoléculaire
2 Roquette Frères

Direct conversion of glucose to 5-hydroxymethylfurfural was studied in a biphasic system, with phosphated niobium oxide-carbon catalysts. We developed a facile approach to generate Nb-based composites with high metal loadings (~20 %) through hydrothermal carbonization (HTC), followed by calcination and H₃PO₄ adsorption. Attention has been paid to the nature of oligosaccharide and amount of water used upon HTC. Catalysts were characterized by XRD, N₂ adsorption, NH₃-TPD, SEM-EDS and XPS. NbP@C-RB30 and NbP@C-RB15 prepared from randomly methylated β-CD in low volumes were found to be more efficient for HMF production, with yields of 32-34 % attained after 3 h in biphasic NaCl-water/methyl isobutyl ketone media. Notably, HTC route provided appropriate conditions for forming acidic Nb₂O₅ nanoparticles, dispersed and maintained over carbon microspheres, and enriched with surface P–OH. These features played an important role for an adequate distribution of the catalyst in the reaction medium composed of two immiscible solvents.

Domaines: Catalyse; Chimie; Chimie organique

Walid Hamza Saadaoui, Cécile Machut, Sébastien Rio, Sandra Bigot, Vincent Wiatz, et al.. Direct conversion of glucose to 5-hydroxymethylfurfural over niobium oxide/phosphate-carbon composites derived from hydrothermal carbonization of cyclodextrins. Molecular Catalysis, 2023, 537, pp.112931. ⟨10.1016/j.mcat.2023.112931⟩. ⟨hal-03943910⟩