The exploration of the synergistic effect in catalysis upon the simultaneous utilization of two sources of power, ultrasound and light, is barely explored and remains a challenging issue. A crucial reason behind this is the difficulty in design and constructing a well-defined sonophotoreactor capable to take advantage of the combination of sonochemistry and photochemistry assets. Herein, we present our successful reactor and a detailed study regarding how the utilization of ultrasonication can act as process intensification tool for the selective and partial photo-oxidation of a biomass derived model compound, benzyl alcohol. The main outcome was the enhanced selectivity in the case of sonophotocatalysis compared to photocatalysis. This selectivity was ascribed to the effects derived from the cavitation phenomena, leading like to hot spots formation and jetting phenomena. Our study can act as a guidance towards understanding the unique effects of ultrasound irradiation as a hybrid process intensification method (HPIM) towards appliance to more complex chemical reactions and manipulation of the nanocatalysts’ photoreactivity in catalytic valorization applications.
Dimitrios A. Giannakoudakis, Dariusz Łomot, and Juan Carlos Colmenares. Green Chemistry (2020). DOI:10.1039/D0GC00329H Open Access!!!