5-Hydroxymethylfurfural (5-HMF) is an important bio-sourced intermediate, formed from carbohydrates such as glucose or fructose. The treatment at 150–250 °C of glucose or fructose in pure water and batch conditions, with catalytic amounts of most of the usual acid-basic solid catalysts, gave limited yields in 5-HMF, due mainly to the fast formation of soluble oligomers. Niobic acid, which possesses both Lewis and Brønsted acid sites, gave the highest 5-HMF yield, 28%, when high catalyst/glucose ratio is used. By contrast, we disclose in this work that the reaction of fructose in concentrated aqueous solutions of carboxylic acids, formic, acetic or lactic acids, used as reactive solvent media, leads to the selective dehydration of fructose in 5-HMF with yields up to 64% after 2 hours at 150 °C. This shows the potential of such solvent systems for the clean and easy production of 5-HMF from carbohydrates. The influence of adding solid catalysts to the carboxylic acid media was also reported, starting from glucose

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Developing high performance catalysts for the low temperature CO 2 reforming with methane (CRM) reaction is a challenge due to the occurrences of metal sintering and carbon deposition. In this study, we synthesized CeO 2 modified Ni@SiO 2 catalysts with excellent properties of sintering-resistance and low carbon deposition for high performance low temperature CRM. The Ni@SiO 2 -CeO 2 catalysts displayed a size effect from tiny Ni nanoparticles to enhance CRM performance and a confinement effect from silica encapsulation to limit Ni sintering and exhibited oxygen storage capacity from ceria to reduce carbon deposition. Performance and characterization results revealed that the Ni@ SiO 2 -CeO 2 -W catalyst with smaller ceria size exhibited higher performance and lower carbon deposition than the Ni@SiO 2 -CeO 2 −E catalyst with bigger ceria size, because the smaller ceria nanoparticles activated more CO 2 . This work provided a simple strategy to deposit small sized ceria on the Ni@SiO 2 catalyst surface for the performance enhancement of low temperature CRM.