Systematic study of H_2 production from catalytic photoreforming of cellulose over Pt catalysts supported on TiO_2

Hydrogen (H₂) production from photocatalytic reforming of cellulose is a promising way for sustainable H₂ to be generated. Herein, we report a systematic study of the photocatalytic reforming of cellulose over Pt/m-TiO₂ (i.e. mixed TiO₂, 80% of anatase and 20% of rutile) catalysts in water. The optimum operation condition was established by studying the effect of Pt loading, catalyst concentration, cellulose concentration and reaction temperature on the gas production rate of H₂ (r_H2) and CO₂ (r_CO2), suggesting an optimum operation condition at 40 °C with 1.0 g·L⁻¹ of cellulose and 0.75 g·L⁻¹ of 0.16-Pt/m-TiO₂ catalyst (with 0.16 wt% Pt loadting) to achieve a relatively sound photocatalytic performance with rH₂ = 9.95 μmol·h⁻¹. It is also shown that although the photoreforming of cellulose was operated at a relatively mild condition (i.e. with an UV-A lamp irradiation at 40 °C in the aqueous system), a low loading of Pt at ~ 0.16 wt% on m-TiO₂ could promote the H₂ production effectively. Additionally, by comparing the reaction order expressed from both r_H2 (a₁) and r_CO2 (a₂) with respect to cellulose and water, the possible mechanism of H₂ production was proposed.