  We investigate the conditions for reactivity enhancement of catalytic
processes in porous solids by use of molecular traffic control (MTC). With
dynamic Monte-Carlo simulations and continuous-time master equation theory
applied to the high concentration regime we obtain a quantitative description
of the MTC effect for a network of intersecting single-file channels in a wide
range of grain parameters and for optimal external operating conditions.
Implementing the concept of MTC in models with specially designed alternating
bimodal channels we find the efficiency ratio (compared with a topologically
and structurally similar reference system without MTC) to be enhanced with
increasing grain diameter, a property verified for the first time for an MTC
system. Even for short intersection channels, MTC leads to a reactivity
enhancement of up to approximately 65%. This suggests that MTC may
significantly enhance the efficiency of a catalytic process for small as well
as large porous particles with a suitably chosen binary channel topology.
