Insights into the Selective Oxidation of 5-Hydroxymethylfurfural to 5-Hydroxymethyl-2-furancarboxylic Acid Using Silver Oxide

This contribution reports the oxidation of HMF to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) employing Ag2O, a relatively cheap and commercially available catalyst, to achieve an impressive HMFCA yield of 98% (60 min, 90 degrees C). Various reaction parameters including type of catalyst, base, quantities of base and catalyst, hydrogen peroxide concentration, and reaction temperature in function of reaction time have been optimized. Microwave batch conditions provided optimum yields, with quantitative HMF conversion with 97% HMFCA yield in only 24 min reaction (30 W). Reusability studies revealed catalyst deactivation, most likely associated with the reduction of silver oxide to metallic silver and nanoparticles sintering after the catalytic reaction.