Catalytic reactions for removal of oxygen from bio-based raw materials are needed to obtain platform chemicals mimicking those used today.
With the inevitable exhaustion of fossil resources, finding renewable bio-based alternatives becomes increasingly important. A major challenge when employing biomass as a renewable resource is the natural high abundance of oxygen. Therefore, catalytic reactions for oxygen removal are needed to obtain platform chemicals mimicking those used today. The project is mainly focused on synthesis of renewable precursors for production of polymers.
In relation to renewable materials, it is desirable to use non-edible biomass, meaning cellulose, hemicellulose, and lignin. A vast amount of reactions have been developed aiming to turn these compounds into either known chemical compounds or novel bio-based building blocks. In both cases, catalysis is fundamental for maintaining efficient and renewable reactions.
When optimizing a given type of catalytic reaction, it is necessary to know the intricate mechanism of the system. This can be determined through experimental studies, such as Hammett studies, or by utilization of labelled compounds. However, it may instead be possible to elucidate the catalytic mechanisms through advanced computational quantum mechanical studies, avoiding the need for laboratory experiments.
In the first part of the project, two reactions for oxygen-removal from biomass were investigated; the deoxy-dehydration and the hydro-deoxygenation reactions. The former was studied using both vanadium and rhenium catalysts, whereas the latter was performed using a molybdenum catalyst. Further, density functional theory (DFT) was applied for elucidation of the intrinsic mechanisms of the reactions. This led to discovery of new types of mechanisms for both reactions, explaining differences in reactivity compared to what was reported in the literature for similar systems.
The second part of the project focused on the utilization of bio-based platform chemicals for synthesis of novel thermo-set polymer materials. Here, the diallyl furan-2,5-dicarboxylate monomer was tested through a plethora of different crosslinking techniques. This monomer is of high interest due to being derived from allyl alcohol and the bio-based building block 2,5-furan-dicarboxylic acid,the latter being a possible replacement for phthalates. The studies led to various new materials, along with new methods for determinations of molecular weights of branched polymer systems, by examining the intrinsic growth patterns of hyper-branched polyester systems.
Summing up, the project has contributed to further development of methods for production of bio-based platform chemicals.
Generally accepted mechanism for the catalytic DODH reaction.