Our research group is interested in the control of catalytic reactions via the organization of functional groups within a heterogeneous solid. This requires us to design a three-dimensional catalytically active structure within a material, using both the pore size and shape encompassing the active site as well as functional group organization within its interior. To accomplish this, we use a method called imprinting and based on a stamping-type process in order to synthesize active catalytically active structures within amorphous materials on the length scale of a small organic molecule. The imprint acts to position chemical functional groups and to create a void with controlled geometry in their immediate vicinity, thus preserving a "memory" of the imprint, in the manner depicted schematically below.
Currently, we are developing imprinting-based syntheses of hybrid organic-inorganic sol-gel materials for asymmetric catalysis, in which chiral information is incorporated within the active site, to direct the stereoselectivity of catalytic pathways. We are also addressing the design and synthesis of metal-containing active structures within these imprinted materials. These structures consist of metal atoms organized by design relative to one another within a ~ 1nm void. Finally, we are attempting to imprint larger (mesoporous) voids for the controlled nucleation and growth of catalyst particles within such voids.