Catalysis with renewables & platform chemicals
Dr. Sandra Hinze
Our research group was established in early 2014. It is supervised by Dr. Sandra Hinze in close collaboration with Prof. Johannes G. de Vries. We are an international team: at the moment, there are scientists from 7 nations working in our laboratories (PostDocs, PhDs, Master and Bachelor students and 1 Technician).
Oil is the dominating feedstock for the chemical industry. With the limited supply of fossil resources, however, this era is coming to an end and research on the conversion of renewable feedstocks into bulk and fine chemicals has gained extraordinary importance, especially the catalytic conversion of inedible plant material, such as cellulose, lignin or lignocellulose. These materials can be converted into a number of platform chemicals, such as ethanol, crotyl alcohol or levulinic acid. Using mostly homogeneous catalysis we want to convert these platform chemicals into high-value chemicals and raw materials for polymers. The following two examples shall give an impression of the group’s approach and expertise.1
Made of wood
Within the last two years the group started to work in two European-wide consortia (GreenSolRes 720695 & HUGS 675325) publicly funded by the EU Horizon 2020 program. Both projects deal with the development and application of processes connected to the synthesis of polymers based on renewable resources. The research is performed in close cooperation between academic and industrial partners. This ensures that current industrial and societal needs are addressed.
The project HUGS for example is based on the production of 100% bio-based plastic bottles, developed by industrial project partner Avantium. They will produce 2,5-furandicarboxylic acid (FDCA). FDCA in turn is the monomeric building block for PEF (polyethylene furandicarboxylate), the plastic material for the bottles. Our research activities focus on the value added to a side product of the process, namely levulinic acid (LA). One of our objectives is the conversion of LA to acrylic acid, which can be utilized as monomeric building block for polymers or to methyl vinyl ketone (MVK) for the synthesis of vitamins (Figure 1).
Noble, yet affordable
As a second example, we wish to highlight our recent research on the selective Ruthenium catalyzed direct hydrogenation of aldehydes and ketones to the corresponding alcohols. These studies were performed in collaboration with DSM and pursued a clear objective: to develop a cheap, stable and active homogeneous metal catalyst for this transformation. Catalysts based on cheap base metals, such as iron, are known in this area, but expensive highly sophisticated ligands are required to deliver high activities. We developed a Ru complex based on so called NNS-ligands, which are prepared from readily available, cheap starting materials in only two steps. The complex proved to be active for a broad substrate scope (TON >200,000), including platform chemicals based on renewables, such as HMF (Figure 2). Additionally, it showed high selectivities towards the carbonyl group in a,b-unsaturated carbonyl compounds.2
Figure 2. Ru-NNS complexes for the selective hydrogenation of aldehydes and ketones to the corresponding alcohols.
- For an overview of the use of homogeneous catalysis in the conversion of renewables and platform chemicals, see: P.J. Deuss, K. Barta, J. G. de Vries, Cat. Sci. Technol., 2014, 4, 1174-1196.
- P. Puylaert, R. van Heck, Y. Fan, A. Spannenberg, W. Baumann, M. Beller, J. Medlock, W. Bonrath, L. Lefort, S. Hinze, J. G. de Vries, Chem. Eur. J. 2017, DOI: 10.1002/chem.201700806.