Comparison of hydrothermal and photocatalytic conversion of glucose with commercial TiO2: Superficial properties-activities relationships

Recently, the photocatalytic conversion of glucose appeared as an environmentally friendly route to produce valuable molecules. However, the potential of this new route in comparison with the usual hydrothermal catalytic process remained questionable. In this paper, we compared the two routes using three commercial TiO2 as catalysts in the same reactor. The TiO2 superficial acidity and basicity were determined by calorimetry and FTIR of CO2, NH3 and pyridine adsorption. Relationships between the acid-base properties, the TiO2 glucose adsorption capacities measured in water and their photocatalytic or hydrothermal performances were proposed: while the photocatalytic performances could be linked to the catalysts? Lewis acid sites density and their glucose adsorption capacities, the hydrothermal performances were dependent of the catalysts? basic/acid sites balance. We highlighted that the conversion of glucose over TiO2 was as efficient with the photocatalytic process at ambient temperature as with the hydrothermal process at 120 ?C. This underlines the potential of the photocatalytic route at the lab scale as regards to the milder experimental conditions involved.

Automated summary

The study compared the efficiency of photocatalytic conversion and hydrothermal conversion of glucose, finding that both processes were equally effective on TiO2, with the photocatalytic process having the potential for milder experimental conditions.