Studies on the kinetics and mechanisms of electrochemical lignin depolymerization on metal oxides

• Grant number: 25/02191-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2025
• End date: May 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: André Henrique Baraldi Dourado
• Grantee: Lucas Dias Germano
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated research grant: 22/06405-1 - Assisted water electrolysis, AP.GR

Abstract

This work proposes an in-depth investigation of the kinetics and mechanism of lignin electro-oxidation in alkaline aqueous media using transition metal oxides such as manganese and molybdenum. Lignin, an abundant aromatic bio-macromolecule in lignocellulosic biomass, presents a high potential as a renewable energy source through the generation of aromatic monomers of great industrial interest, offering a sustainable alternative to petroleum derivatives. However, there is still a lack of a more robust and in-depth understanding of the kinetic and mechanistic aspects of lignin electro-oxidation in alkaline aqueous media. To elucidate the details of the reaction, spectroscopic (UV-Vis, FTIR, Raman) and analytical techniques (chromatography, mass spectrometry, NMR) coupled in situ to the electrochemical system will be employed. The use of MnO2 and MoO3 nanowires and nanoplates, obtained by the hydrothermal synthesis methodology, will allow the evaluation of the influence of the morphology and crystalline structure of the catalysts on the efficiency of the depolymerization. The main objective of this study is to identify the intermediate species generated during lignin electro-oxidation and elucidate the role of intermediates in the kinetics and mechanism of the reaction. The results obtained will contribute to the development of more efficient and selective processes for the valorization of lignin, opening new perspectives to produce biofuels and high-value chemicals.