Photocatalytic Cellulose Reforming for H<sub>2</sub> and Formate Production by Using Graphene Oxide-Dot Catalysts
Van‐Can Nguyen, Dipak B. Nimbalkar, Le D. Nam, Yuh‐Lang Lee, Hsisheng Teng
Abstract
The mechanism of photocatalytic biomass reforming for H2 production is far from fully understood. This study uses functionalized graphene dots with Pt-cocatalyst to reform cellulose in an alkaline solution under 1 sun illumination. Reforming of cellulose is initiated with the peeling of its constituent d-glucose units, which subsequently transform into deprotonated isosaccharinic acid (C6). Further degradation of C6 into molecules C5-C1 proceeds through successive alternation of C-eliminating hydrolysis and photocatalytic oxidation of C6 derivatives. The C6-C1 species are quantitatively identified using chromatography and mass spectroscopy. The end C-containing product is predominantly HCOO– rather than HCO3– (or CO2). The photocatalytic oxidation is accompanied by the photocatalytic reduction of water to produce H2. This reforming steadily produced H2 for 6 days with a negligible rate decay, accomplishing 35% of the theoretical ultimate value for the reforming of cellulose. This study elucidates the detailed mechanism in the photocatalytic reforming of cellulose.