Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia

OP-2-6KINETICS OF SELECTIVE OXIDATION OF SUGARSOVER GOLD CATALYSTSBright T. Kusema 1 , Betiana Campo 1 , Olga Simakova 1,2 , Päivi Mäki-Arvela 1 ,Tapio Salmi 1 , Dmitry Yu. Murzin 11 Laboratory of Industrial Chemistry and Reaction Engineering Process ChemistryCentre, Åbo Akademi University, FI-20500 Åbo/Turku, FinlandE-mail: bright.kusema@abo.fi2 Boreskov Institute of Catalysis SB RAS, Novosibirsk, RussiaChemicals derived from various renewable sources have drawn great interestdue to their features such as their ability to produce biodegradable and biocompatiblenew products as well as value-added chemicals. Arabinogalactans (AG) arehemicelluloses found in large quantities in larch species and they account for 15-25weight % of dry wood material. The average ratio of galactose, arabinose andglucuronic acid in AG is about 5:1:0.08. AG can be converted into valuable productsby a two step approach, which includes hydrolysis of AG to monomers and catalytictransformation of the sugars into bio-based valuable products having manyapplications in the food, detergent, pharmaceutical and cosmetic industries [1,2].The focus of this research was on kinetics of selective oxidation of arabinose andgalactose to arabinonic and galacturonic acid respectively over supported goldnanoparticles. Au samples were prepared by direct ion exchange, deposition withurea and impregnation. The influence of reaction parameters such as oxygen flowrate (2.5–5.0 ml/min), pH (6–10) and temperature (60–90°C) was investigated. Theactivities and initial rates of the catalystsstudied showed a strong dependence onthe pH of the reaction medium withslighly alkaline conditions and moderatetemperatures exhibiting high conversionand selectivity. Figure 1 shows thekinetic curves of arabinose oxidation by2% Au/Al 2 O 3 at pH 8 and 60°C.References:[1]. Kusema, B.; Xu, C.; Mäki-Arvela, P.; Willför, S.; Holmbom, B.; Salmi, T.; and Murzin, D. Kineticsof acid hydrolysis of arabinogalactans, I. J. Chem. Reactor Eng., 2010, Vol. 8, 1.[2]. Baatz, C.; Prüße, U. Preparation of gold catalysts for glucose oxidation, Catalysis Today, 2007,Vol. 122, 325-329.48