Project description
New catalysis technique could make solvents redundant
The EU-funded Mechanocat project plans to study a new mechanochemical technique for conducting catalytic reactions in ball mills. The catalyst will be the milling ball itself – it will neither be dissolved (as in homogeneous catalysis), nor will it be a powder or bed of shaped bodies (as in heterogeneous catalysis). The milling balls will be refreshing their catalytically active surface constantly when colliding with other milling balls. Researchers are keen on figuring out how solid reactants can be brought into reactions in the absence of solvents. The proposed solid-state approach is fundamentally different from the conventional solution-based processes, opening up the opportunity for catalysing new reactions.
Objective
I propose a novel concept of catalysis neither utilizing light, thermal heating nor an electric potential as in conventional catalysis, but simply mechanical energy. In this mechanochemical approach, mechanical energy is provided by the collision of milling balls inside a ball mill. The catalyst is neither dissolved (as in homogenous catalysis), nor a powder or bed of shaped bodies (as in heterogeneous catalysis), but the milling ball itself. I want to study how even in the absence of any solvent, solid reactants can be brought into reactions mechanocatalytically - only using milling balls that refresh their catalytically active surface constantly during their continuous collisions. I want to showcase this concept for a type of reactions that is commonly in the hand of homogeneous catalysis – C-C-cross coupling reactions catalysed by Pd, Cu or Ni. Understanding this novel concept involves 1) identifying reactions and reactants that can be applied to direct mechanocatalysis, 2) elaborating how mechanochemical reaction parameters such as milling speed, ball size and ball roughness replace common reaction parameters such as concentration or type of solvent and 3) elucidating the underlying mechanisms by employing in situ characterization techniques that allow for the monitoring of the reaction directly inside the moving milling vessels.
I believe direct mechanocatalysis to be ground-breaking as it involves reactants that can hardly be brought into reaction via conventional approaches because of low solubility or limited stability in solution. The proposed solid-state approach will be fundamentally different from the conventional solution-based procedures, and I foresee new reactions to be possible. This approach is highly sustainable as it makes the use of any solvent obsolete and may develop to a new type of catalysis due to the exceptionally facile catalyst separation after synthesis; simply taking the milling ball out of the vessel.
Fields of science
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Funding Scheme
ERC-STG - Starting GrantHost institution
44801 Bochum
Germany