Nanostructured Metal Catalysts for Continuous-Flow Catalytic Processes

The possibility of combining the favorable features of continuous-flow systems with metal nanostructured catalytically active materials, within the same microfluidic device, can represent a strategic advantage in the perspective of a progressive intensification of organic production processes and their future economic and environmental sustainability. Although this idea has recently attracted a great deal of interest, its actual use for the preparation of high added-value products is extremely limited. Several scientific problems are still awaiting a satisfactory solution for applications in pharmaceuticals and industrial environment. First of all, in order to reduce the product contamination and to make the system longer lasting under flow conditions, the efficient synthesis of leach-proof, highly active, solid metal catalysts needs to be implemented. [1]

This research involves the design and the synthesis of innovative nanostructured metal catalysts and their use in devices (continuous flow reactors, CFRs) for selective carbon-carbon bond forming reactions (e.g. Heck, Sonogashira, Suzuki-Miyaura, and Glaser couplings) leading to synthetically relevant fine-chemicals.
Mono- (e.g. Pd and Cu) and bimetallic nanoparticles (e.g. Pd-Cu) are synthesized by the innovative metal vapour synthesis (MVS) technique, or by more conventional methods, and deposited onto mechanically and thermally stable supports with suitable fluid-dynamic properties. In order to make leach-proof catalysts, longer lasting under flow conditions, different synthetic strategies are take into account: a) deposition of metal nanoparticles onto inorganic or hybrid organic-inorganic supports in form of powder; b) immobilization of nanoparticles onto macroporous polymeric (e.g. polystyrene) or inorganic (e.g. silica-based) monoliths.
The ultimate goal is the development of sustainable processes by designing packed-bed or monolithic catalytic continuous flow reactors (CFRs) provided with an optimal combination of activity, selectivity, low metal leaching and, obviously, economic convenience.

This research activity is financed by the MIUR (project FIRB 2010 “Futuro in ricerca”, “Multifunctional hybrid materials for the development of eco-sustainable catalytic processes”).

References:

[1] a) Wiles, C.; Watts, P. Green Chem. 14 (2012) 38-54; b) Frost, C.G; Mutton, L.  Green Chem. 12 (2010) 1687–1703; c) Noel, T.; Buchwald, S.L. Chem. Soc. Rev. 40 (2011) 5010-5029; d) Kirchning, A.; Solodenko, W. Mennecke, K. Chem. Eur. J. 12 (2006) 5972-5990.