Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia

OP-2-12SELECTIVE OXIDATION OF SUGARS USING NANODISPERSEDPt, Pd AND Au SUPPORTED CATALYSTSTaran O.P. 1 , Delidovich I.V. 1 , Matvienko L.G. 1,2 , Simonov A.N. 1,2 ,Moroz B.L. 1,2 , Pyrjaev P.A. 1,2 , Simakova I.L. 1 , Kholodovich A.N. 1 ,Bukhtiyarov V.I. 1,2 , Parmon V.N. 1,21 Boreskov Institute of Catalysis, 2 Novosibirsk State University,Novosibirsk, Russian Federation, E-mail: oxanap@catalysis.ruCarbohydrates constitute the major part of the renewable feedstock for chemicalindustry. Polyoxoacids being sugar oxidation products are widely used for synthesisof pharmaceuticals, food additives, cleaning agents, and other demanded products.This work was aimed on the revealing the correlations between the catalyticperformance of monometallic Pt, Pd and Au catalysts towards oxidation of sugarsand nature of active metal, its oxidation state and dispersion. Sugars with differentstructure and positions of functional groups (glucose, sorbose, lactose) were used asmodel substrates.The Pt/Sibunit, Pd/Sibunit, Au/Al 2 O 3 and Au/Sibunit catalysts were synthesized,characterized and tested for the oxidation of sugars in aqueous solutions.Common tendencies were revealed for the oxidation of aldosugars (glucose andlactose). The catalytic activity increases in the order: Pt < Pd < Au, at the selectivityto corresponding acids up to 98% at total substrate conversion. Specific catalyticactivity of Pt and Au does not depend on the metal mean particle size in the 1-5 nmrange for Pt and 2-20 nm for Au. It was found that finely dispersed Pd/C catalysts(=3 nm) are easier deactivated than samples with larger metal particles(=6 nm) under kinetic controlled conditions. The stability of Pd nanoparticlesincreases under diffusion control. The dependence of catalytic activity and stabilityagainst deactivation on Pd oxidation state was studied by XPS.The catalytic activity of Pt towards selective oxidation of sorbose exceeds thoseof Pd and Au. The selectivity of formation of 2-keto-gulonic acid never exceeds 20%.The reaction pathways of catalytic sorbose oxidation were proposed basing on theresults of HPLC-MS analysis of the reaction mixture.Acknowledgements:The financial support of RFBR grants 08-03-00823, 08-03-91758, 09-03-12272 andRussian Federal Innovation and Science Agency via the program «Scientific and Educationalcadres» is gratefully acknowledged.55