Hydrothermal process assisted by photocatalysis: Towards a novel hybrid mechanism driven glucose valorization to levulinic acid, ethylene and hydrogen

The effect of UV irradiation on titanium dioxide catalyzed glucose conversion in value added molecules was studied at high temperatures, 120-150 ?, in anaerobic conditions. The reaction was implemented in a batch reactor designed to combine high temperature/pressure and irradiation. Inhibition of the titanium dioxide catalytic performances to produce gluconic acid was observed upon UV irradiation which allows the selective formation of levulinic acid in high yield, similar to 60% at 150 ?, together with the co-production of ethylene and hydrogen in the gas phase. The formation of levulinic acid could be explained by the creation of Bronsted acidity in the reaction medium upon irradiation. The reasons of this phenomenon are discussed considering that UV could modify the electronic properties of titanium dioxide by electron-holes pairs formation and the possible H+ promotion.

Automated summary

By UV irradiation, the electronic properties of titanium dioxide can be altered, promoting the generation of H+ and inhibiting the performance of titanium dioxide catalyst in producing gluconic acid. This allows for the selective formation of levulinic acid with high yield.