This project aims to develop a novel method for the transformation of lignin-based model compounds into valuable chemical precursors. The principle is to assist the photocatalytic oxidation process with low-frequency ultrasound (US) and new catalytic materials possessing excellent redox and sonophotocatalytic properties. The objective is to improve the photocatalytic selective oxidation of lignin-based model compounds through the physical effects of low-frequency sonication (e.g., effective mass transfer, microstreaming, in situ photocatalyst regeneration, etc, effects often inaccessible through conventional methods) and understanding the mechanism of the synergistic action of green sources of energy (ultrasound and solar energy) to control the production of high-value chemicals during a liquid phase sonophotocatalytic selective process. The exploration of all resulting products formed in the gas and liquid phase, along with their selectivity according to the physicochemical, optical and redox properties of the involved catalysts, will allow to gain a detailed knowledge that is central to fully understand the parameters and mechanisms in this new concept of biomass treatment. In this project will be used our well-defined (e.g. ultrasound-assisted sol-gel) methods for the synthesis of nanostructured metal oxide-based semiconductors. It will be carried out the study of the physicochemical properties of semiconductor materials (before and after (sono)-(photo)-catalytic test reactions) and testing them in the selective sonophotocatalytic oxidation of lignin-inspired model compounds (in liquid-phase) as a promising method of lignin-based molecules valorization. A systematic basic research of the effect of green and unconventional source of ultrasonic energy on low-temperature photocatalytic transformation of lignin-derivate model compounds will be carried out.
A positive outcome of the proposed project has the potential of strong influencing on the field of green materials synthesis and processes, renewable energies and clean/effective chemicals production from organic wastes. Therefore, the final outcome of the proposal will lead to profound benefits to humanity in the long term. These pioneering studies will permit us to understand and optimize (a) the synergistic effect of combining ultrasound with heterogeneous photocatalysis (new hybrid technology), and thus (b) predict photocatalyst performances manipulated by the full control of ultrasound effects during the selective oxidation of lignin-based molecules, what will result in (c) activity/selectivity/stability improvement of promising photocatalysts working thanks to solar light utilization and sonication which open the possibilities for better ways of management and valorization of lignin-containing organic wastes. The uniqueness of this project rests on a combined approach of understanding/design/synthesis of an effective semiconductor-based photocatalyst with optimized composition working in optimized sonophotocatalytic conditions for the valorization of lignin-based model compounds.
Project title: “Understanding the mechanism of lignin-based model molecules selective conversions to phenolics via ultrasound-assisted heterogeneous photocatalysis”
Financed by the National Science Centre in Poland
Project leader: Prof. Dr. Juan Carlos Colmenares Quintero
OPUS 13 results: