Title:	Application of Computational Quantum Chemistry for Understanding Depolymerization of Lignin
DNr:	SNIC 2018/3-114
Project Type:	SNIC Medium Compute
Principal Investigator:	Joseph Samec <joseph.samec@su.se>
Affiliation:	Stockholms universitet
Duration:	2018-03-01 – 2018-07-01
Classification:	10405 10407
Homepage:	http://www.organ.su.se/jsm/
Keywords:

Abstract

The project primarily concerns the mechanistic investigation of the depolymerization of lignin. We will apply quantum chemical calculations using density functional theory methods to understand the ground state and excited state potential energy surfaces involved in various degradation pathways of lignin. Lignin, a heterogeneous aromatic biopolymer, is present in plant cell walls along with cellulose and hemicelluloses. There is a need to find mild, efficient and cost-effective ways to produce biofuel and commodity chemicals from lignin. Variety of delignification methods, i.e., physical, chemical, and biological are known. Now a days, photocatalytic processes are also attracting broad interest in the degradation of lignin. A combined computational and photocatalytic approach could provide an insight to develop new efficient ways for lignin degradation (Figure 1). Lignin is characterized by several different chemical bonding motifs, i.e., β-O-4, β-1, β-5, 4-O-5, and 5-5. This project in particular will focus on aryl-aryl bond breaking in the bonding linkage 5-5 which is much less explored. Computational calculations are therefore needed to investigate the ground and excited state potential energy surfaces that will help to elucidate the mechanism of the depolymerisation of lignin. Ar-Ar -> 2 Ar Figure 1: Oversimplified representation of the main objective.