Photocatalytic Cellulose Reforming for H2 and Formate Production by Using Graphene Oxide-Dot Catalysts

The mechanism of photocatalytic biomass reforming for H-2 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 6-glucose units, which subsequently transform into deprotonated isosaccharinic acid (C-6). Further degradation of C-6 into molecules C-5-C-1 proceeds through successive alternation of C-eliminating hydrolysis and photocatalytic oxidation of C-6 derivatives. The C-6-C-1 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 H-2. This reforming steadily produced H-2 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.

Automated summary

This study investigates the photocatalytic reforming mechanism of cellulose using functionalized graphene dots with Pt-cocatalyst in an alkaline solution. The process involves the peeling of cellulose into 6-glucose units, transforming into deprotonated isosaccharinic acid (C-6) and further degradation into C-5-C-1 molecules. The end product is predominantly HCOO- with photocatalytic reduction of water to produce H-2.