Dynamic Catalysis Fundamentals: II. Consequences of scaling relationships on mechanisms and kinetics

Dynamic catalysis proffers a new strategy for leveraging linear free energy (LFE) relationships in catalysis to increase reaction rate, conversion, and selectivity by high-frequency, forced kinetic oscillations. This work explicates two dynamic catalysis mechanisms—“resonance” and quasi-static, characterized by finite frequency bands and high frequency limits, respectively—and details the necessary LFE parameters necessary for each dynamic catalysis phenomena to arise. Detailed analytical and numerical analyses reveal that under quasi-static mechanisms, Sabatier limits on reaction rates and thermodynamic limits on conversion can be completely subverted with sufficiently large kinetic oscillation amplitudes. In resonance mechanisms, reaction rates and conversion are still limited by Sabatier volcanos and thermodynamic equilibrium constants, respectively; however, these imposed limitations are those for a subset of elementary steps, rather than for the entire overall reaction. An investigation of dynamic catalysis for reaction schemes with multiple products reveals that quasi-static dynamic catalysis can drive selectivities of any intermediate or product to 100%, provided the appropriate LFE relationships.