My research now with Dr. Jim Evans focuses on modeling and analysis of the Interplay between catalytic reaction kinetics and anomalous transport in mesoporous systems. Anomalous transport means that molecules within the narrow pores of the mesoporous catalytic material either cannot pass each other, resulting in so-called single-file diffusion, or at least have difficulty in passing each other.
Our specific focus is on simple first-order conversion reactions, A->B (see Fig), occurring inside a parallel array of linear nanopores of a catalytically functionalized material such as mesoporous silica. Reactants, A, enter the pore openings, diffuse to adjacent empty cells of a 1D linear lattice at rate h, convert to a product at catalytic cells (c), B, with microscopic rate k, and both reactants and products can diffuse out of the pore. The cell width a is chosen as 1 nm comparable to species size. This would correspond to single-file diffusion with a strict no-passing constraint. We also allow positional exchange of adjacent A and B at rate Pexh to relax the strict single-file constraint, noting that exchange of adjacent particles of the same type has no effect. We apply statistical mechanical modeling (adopting spatially discrete stochastic lattice-gas models) to analyze A->B conversion reactions in linear nanopores with inhibited transport.
Figure: Schematic of the key steps in A->B catalytic conversion reaction model. “c” denotes catalytic cells where reaction occurs at rate k. Behavior is shown in two adjacent pores, which should be regarded as part of larger array of pores.