The CatASus project has delivered groundbreaking scientific results related to the catalytic valorization of lignocellulosic biomass to amines. By forging new methods of depolymerization of lignocellulosic biomass to platform chemicals (cleave), and subsequent coupling of these platform chemicals preferantially with amines (couple) we were able to access new sustainable value chains towards bio-based products. For both these key focus areas, specific catalytic methods have been developed.
WP1> Lignin depolymerization: Lignin-first biorefining has emerged as a new enabling method that unlocks the potential of native lignin and delivers high yield and selectivity of aromatic monomers. This project has significantly contrinuted to establihing this new field of biorefining, introducing 2 main methods, namely 'reductive catalytic fractionation' and 'diol assisted fractionation' which relies on stabilization of reactive intermediates during acidolysis. (examples for papers: on RCF: Nature Catalysis, 2018, 1, 82-92; On acidolysis: J. Am. Chem. Soc., 2016,138(28), pp 8900–8911. A perspective paper [Nature Rev Chem, 2020, 4, 311–330].
During the course of research, as proposed in the DOA we have engaged in catalyst development, method development, mechanistic elucidation, model compound studies, lignini studies, and moving entirely to raw lignocellulosic biomass.
WP2> The catalytic valorization of the cellulose fraction proceeded hand-in-hand with lignin chemistry, matching the actual biorefinery approach established. Overall, the project introduced full sustainable biorefinery concepts whereby both the efficient valorization of lignin, cellulose and hemicellulose are targeted. This involved in specific cases the conversion of cellulosics to HMF derivatives, for example towards bio-based polymers [Nature Comm., 2022, 13, 33762022], or the conversion of cellulose to aviation fuels by catalytic depolymerization and C-C coupling reactions [Nature Catalysis 2018, 1, 82].
WP3> The the development of homogeneous /and heterogeneous catalytic methods for diverse N-alkylations of ligncellulose derived platform chemicals was developed. We have identified a range of ho catalytic methods for the direct coupling of amines/and or ammonia with bio-based platfrom chemicals. {Science Advances 2017, 2017, 3 (12), eaao6494], biologically active molecules: [ACS Cent. Sci. 2019, 5, 10, 1707-1716].
Another important research area was to provide specific amines for the production of bio-based polymers. [Chem Catalysis 2021, 1, 7, 1466-1479]
WP4 – This work package deals with the integration of all developed catalytic methods, and placing these into overall biorefinery concepts, which has been accomplished beyond expectations and well-beyond state of the art. Specific products classes, and collaborations with polymer chemist, medicinal chemists, separation chemistry, biological activity testing were established. Original concept: Cleave and couple has been put forward and discussed in talks and perspective articles: [Z. Sun, K. Barta, Chem Commun, 2018, 54, 7725-7745.]
The project results were broadly presented on scientific conferences, and meetings and >30 invited talks and seminars. The PI was appointed Chair of Gordon Conference of Lignin valorization 2022, and the Chair of EuChemSoc Division Green and sustainable chemistry.
Research awards for the work done were: NCCC conference award for early carrer scientist in 2019, the prestigious ACS Sustainable Chemistry and Engineering Lectureship award 2020, Styria innovation award 2021.
The result lead to the successful aquiry of the ERC PoC Grant PURE in 2019, as well as the EIC Transition Grant PureSurf 2021.
