Cooperative effect of cobalt acetylacetonate and silica in the catalytic cyclization and oxidation of fructose to 2,5-furandicarboxylic acid

Cobalt acetylacetonate encapsulated in sol-gel silica is shown to be a very efficient bifunctional acidic and redox catalyst, giving 2,5-furandicarboxylic acid with 99% selectivity directly from fructose at a conversion of 72%. A cooperative effect of the functions of the catalyst is operative, as the same reaction performed in two consecutive steps gives much lower conversions. (C) 2002 Elsevier Science B.V. All rights reserved.