Polar-Soluble Ligands and Multiphase Flow Systems for Hydroxycarbonylation of Renewable Alkenes

• Applicants: Dr. Thomas Seidensticker; Privatdozent Dr. Andreas Vorholt
• Subject Area: Technical Chemistry
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 573488647

The German–Singaporean research project Carbonflow addresses fundamental questions in the field of sustainable catalysis, with a focus on palladium-catalyzed carbonylation reactions. These reactions, considered particularly atom-economical and resource-efficient, convert alkenes – including those derived from renewable feedstocks – with carbon monoxide and a nucleophile into valuable carboxylic acid derivatives. While industrial carbonylation processes typically rely on alcohols (alkoxycarbonylation), the closely related transformation using water (hydroxycarbonylation) remains poorly explored and is not established on a technological level. This is primarily due to low reaction rates and unresolved challenges related to catalyst solubility, phase separation, and catalyst stability in aqueous multiphase systems. The aim of this interdisciplinary project is to gain deeper mechanistic insight into these challenges. To this end, new polar-soluble diphosphine ligands will be developed and synthesized that combine high selectivity with long-term catalyst stability. These novel ligands will be studied under realistic, continuous process conditions—an approach that has not yet been explored for hydroxycarbonylation reactions. To achieve this, Carbonflow brings together three complementary research teams. The group of Dr. James Nobbs (A*STAR, Singapore) designs and synthesizes ligands with different polar solubility tags. These ligands are tested by Dr. Thomas Seidensticker’s group (TU Dortmund) using microstructured flow reactors that allow precise control of gas–liquid systems and can operate with minimal catalyst quantities. A particular strength lies in the segmented multiphase flow regime within capillaries, which intensifies mass transport and minimizes back-mixing—both critical factors for selective reactions involving gaseous CO. The project is further strengthened by the expertise of Dr. Andreas Vorholt (MPI CEC, Mülheim), whose team has developed advanced spectroscopic techniques for real-time monitoring of catalyst behavior. These operando analyses offer unique insight into catalyst activity and deactivation mechanisms under real reaction conditions. The strength of Carbonflow lies in the close integration of ligand design, reactor development, and mechanistic analysis. Only through this interdisciplinary and international collaboration can the key scientific questions—such as the relationship between ligand structure, catalyst stability, and selectivity—be systematically addressed. The project thus makes a significant contribution to the fundamental understanding of sustainable multiphase catalysis and opens new long-term perspectives for the use of renewable feedstocks in chemical synthesis.

• DFG Programme: Research Grants
• International Connection: Singapore
• Partner Organisation: Agency for Science, Technology and Research (A*STAR)
• Cooperation Partner: Dr. James David Nobbs