Visible‐Light‐Controlled Oxidation of Glucose using Titania‐Supported Silver Photocatalysts. Issue 22 (13th October 2016)

• Record Type: Journal Article
• Authors: Da Vià, Luigi; Recchi, Carlo; Davies, Thomas E.; Greeves, Nicholas; Lopez‐Sanchez, Jose A.
• Is Part Of: ChemCatChem. Volume 8:Issue 22(2016)
• Page Start: 3475
• Page End: 3483
• Publication Date: 2016-10-13
• Subjects: biomass -- oxidation -- photocatalysis -- silver -- supported catalysts; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.201600775
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: The visible‐light‐mediated photo‐catalytic selective valorisation of glucose using TiO2 ‐supported Ag nanoparticles is shown for the first time. The optimisation of the catalyst composition, substrate‐to‐catalyst ratio and reaction medium proved that a near total suppression of the mineralisation pathway could be achieved with a selectivity to partial oxidation products and small‐chain monosaccharides as high as 98 %. The primary products were determined to be gluconic acid, arabinose, erythrose, glyceraldehyde and formic acid. Under UVA light, the selectivity to organics decreases because of the production of CO2 from mineralisation. A reaction mechanism is proposed based on an α‐scission process combined with the Ruff degradation reaction, which explains the presence of the oxidation products, the smaller carbohydrates and formic acid. X‐ray photoelectron spectroscopy, UV/Vis spectroscopy and microscopy studies showed the presence of plasmonic 4 nm particles of silver that were oxidised to silver oxide over the course of the reaction, and recycling studies revealed that this was not detrimental to activity. Abstract : The light fantastic : The visible‐light‐mediated photocatalytic valorization of glucose using TiO2 ‐supported Ag nanoparticles is shown for the first time. The primary products are gluconic acid, arabinose, erythrose, glyceraldehyde, and formic acid. A combined reaction mechanism is proposed based on an α‐scission process combined with the Ruff degradation reaction, which explains the presence of the oxidation products, monosaccharides, and formic acid.