AuPd nanoparticles supported on NiO exhibit high activity and stability in the base free oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA).

In this study, 5-hydroxymethylfurfural (HMF) oxidation was carried out via both the catalytic and the photocatalytic approach. Special attention was devoted to the preparation of the TiO₂-based catalysts, since this oxide has been widely used for catalytic and photocatalytic application in alcohol oxidation reactions. Thus, in the catalytic process, the colloidal heterocoagulation of very stable sols, followed by the spray-freeze-drying (SFD) approach, was successfully applied for the preparation of nanostructured porous TiO₂-SiO₂ mixed-oxides with high surface areas. The versatility of the process made it possible to encapsulate Pt particles and use this material in the liquid-phase oxidation of HMF. The photocatalytic activity of a commercial titania and a homemade oxide prepared with the microemulsion technique was then compared. The influence of gold, base addition, and oxygen content on product distribution in the photocatalytic process was evaluated.

Over the past decade, a great deal of effort has been devoted to developing reductive processes in the field of biomass valorisation for the sustainable production of bio-fuel additives and chemicals. Catalytic transfer hydrogenation, which uses alcohol as the hydrogen source, is an interesting approach that avoids the use of both high H₂ pressure and precious metal catalysts. In this work, the vapour-phase production of 2-methylfuran from biomass-derived furfural (FU), using methanol as the H-transfer agent and FeVO₄ catalyst, was studied. At a temperature of 320 °C it was possible to achieve 80% yield of 2-methylfuran, with small amounts of 2,5-dimethylfuran and 2-vinylfuran as by-products. Catalyst characterization highlighted that FeVO₄ reduction took place under the studied conditions, leading to the in situ development of a true active phase. The study of the reaction network permitted us to infer on the relative contribution of H-transfer and hydrogenation, the latter from the in situ generated formaldehyde and H₂, to 2-methylfuran, formation. The reported results indicate the potential application of H-transfer with FeVO₄ catalysts as an efficient process for the selective de-oxygenation of biomass-derived molecules.