Projektbeschreibung
Neues Katalyseverfahren ohne Lösungsmittel?
Das EU-finanzierte Projekt Mechanocat plant die Untersuchung eines neuen mechanisch-chemischen Verfahrens zur Durchführung katalytischer Reaktionen in Kugelmühlen. Katalysator wird die Mahlkugel selbst sein, jedoch wird sie weder gelöst (wie bei der homogenen Katalyse), noch wird sie ein Pulver oder ein Bett aus Formkörpern (wie in der heterogenen Katalyse) sein. Wenn die Mahlkugeln miteinander kollidieren, erneuern sie ständig ihre katalytisch aktive Oberfläche. Das Forschungsteam arbeitet daran herauszufinden, wie feste Reaktionspartner ohne Lösungsmittel zum Reagieren gebracht werden können. Der vorgeschlagene Festkörperansatz unterscheidet sich grundlegend von den konventionellen lösemittelbasierten Verfahren und eröffnet die Möglichkeit der Katalyse ganz neuer Reaktionen.
Ziel
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.
Wissenschaftliches Gebiet
Programm/Programme
Thema/Themen
Finanzierungsplan
ERC-STG - Starting GrantGastgebende Einrichtung
44801 Bochum
Deutschland