THE OXIDATION OF FRUCTOSE ON PT C CATALYSTS - THE FORMATION OF D-THREO-HEXO-2,5-DIULOSE AND THE EFFECT OF ADDITIVES/

This paper describes a study on the oxidation of D-fructose with molec ular oxygen on Pt/C catalysts. Two major products are formed: 2-keto-D -gluconic acid and D-threo-hexo-2,5-diulose ('5-ketofructose'), Deacti vation of the catalyst was observed, caused both by overoxidation of t he active surface and inhibition of the reaction by 2-ketogluconic aci d. Although promotion of the catalyst with bismuth did not prevent dea ctivation, it improved the selectivity to 2-ketogluconic acid, probabl y due to coordination of fructose to the promoter. Other promoting met als (tin, lead and antimony) and additives like berate and hexamethyle netetramine were less successful. (C) 1997 Elsevier Science Ltd. All r ights reserved.