Design of efficient photocatalytic processes for the production of hydrogen from biomass derived substrates

The photoreforming of glucose has been studied over TiO₂ photocatalyst with different photoreactors, focusing on the effect of the reaction conditions: temperature, pressure, catalyst and substrate concentration. The effect of pressure was particularly significant, decreasing hydrogen evolution rate, but improving the conversion of the substrate. Furthermore, pressure moderately higher than ambient allowed to operate at high temperature (80 °C), boosting hydrogen productivity. Most experiments were carried out on glucose photoreforming, but, for the first time, the photoconversion of levulinic acid was investigated, as an interesting product of biomass hydrolysis under harsh conditions. Levulinic acid led to the production of ethane and ethylene in gas phase, interpreted according to a preliminary hypothesis of the photoconversion mechanism. High hydrogen productivity was achieved, in most cases higher than the literature benchmark.