Efficient multi-step reaction cascades can directly benefit the manufacture of advanced materials, energy conversion/harvesting, and human-machine interfaces. Nature has developed very efficient pathways to carry out multi-step reactions with controlled transport and kinetics.1One such approach to reaction control is the confinement of active sites and the resulting reaction intermediates within a physical tunnel, by which the intermediate can be restricted from the bulk. Studying transport properties and kinetics of the confined systems provides a framework for the design of integrated catalytic systems and process intensification.
In the present study, computational modeling has been performed to study the effect of geometric, kinetic, and transport parameters on intermediate channeling via confinement, using a continuum model(Figure 1 a). The efficiency of transport is quantified by reactant yield and flux control coefficients (FCC).2 Interaction of the intermediate with the confined channel has been addressed by molecular dynamics studies of diffusion coefficient and retention time(Figure 1 b). Electrostatic effects of the tunnel edge on the intermediate significantly increase retention of intermediate within the tunnel. Such retention of intermediates within the confined assembly, with minimal access to bulk solution, is shown to be the key to efficient channeling.
Acknowledgement
We gratefully acknowledge support from Army Research Office MURI (#W911NF1410263) via The University of Utah.
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