Catalytic Oxidation of Glucose with Hydrogen Peroxide and Colloidal Gold as Pseudo-Homogenous Catalyst: A Combined Experimental and Theoretical Investigation

• Main Authors: Jitrayut Jitonnom, Christoph Sontag
• Format: บทความวารสาร
• Language: English
• Published: Science Faculty of Chiang Mai University 2019
• Online Access: http://it.science.cmu.ac.th/ejournal/dl.php?journal_id=7069; http://cmuir.cmu.ac.th/jspui/handle/6653943832/63774
• Institution: Chiang Mai University

Gold nanoparticles have been proved to act as oxidation catalyst for glucose oxidation, offering a “chemical” synthetic route to gluconic acid and gluconates - nowadays commercially produced by an enzyme catalyzed oxidation. Our investigations of the gold catalyzed oxidation route showed that gold nanoparticles produced by a modified Turkevich method have a high activity for this pseudo-homogenous catalytic reaction. Under mild reaction conditions, glucose could be oxidized in good yields (~70%) and the resulting gluconate could be isolated by column chromatography and precipitation as calcium salt. The catalytic oxidation reaction was found to follow the first-order kinetic with a rate constant of 4.95 h-1, in good agreement with previous finding. The underlying reaction mechanism is discussed, assuming that the formation of a gold-glucose cluster intermediate is a key catalytic step. Several structures of the gold-glucose intermediates were examined using density functional theory methods. The molecular behavior of glucose adsorption in gold colloid solution is present.