Catalytic conversion reactions in nanoporous systems with concentration-dependent selectivity: Statistical mechanical...

Area of Science:

• Chemical Engineering
• Physical Chemistry
• Materials Science

Background:

• Catalytic conversion reactions are crucial in chemical synthesis.
• Product selectivity in heterogeneous catalysis is often influenced by transport phenomena within catalyst pores.
• Understanding diffusion limitations and their effect on reaction outcomes is essential for catalyst design.

Purpose of the Study:

• To develop a statistical mechanical model for catalytic conversion reactions within nanoporous catalysts.
• To investigate the concentration-dependent selectivity of products (Bc or Bt).
• To elucidate the influence of restricted diffusion and spatial correlations on reaction selectivity.

Main Methods:

• Statistical mechanical modeling of catalytic conversion (A→Bc or Bt).
• Incorporation of concentration-dependent selectivity.
• Analysis of reactions within narrow linear nanopores considering restricted diffusive transport, including single-file diffusion.
• Comparison of kinetic Monte Carlo simulations with analytic treatments.

Main Results:

• Restricted diffusive transport within nanopores induces significant concentration gradients.
• Selectivity is shown to be impacted by strong spatial correlations arising from restricted diffusivity.
• Subtle clustering of reactants (A) also plays a role in influencing selectivity.

Conclusions:

• Restricted diffusion and reactant clustering are critical factors governing selectivity in nanoporous catalysts.
• The developed model provides insights into the interplay between transport phenomena and reaction kinetics.
• This work offers a framework for understanding and potentially controlling product distribution in nanoscale catalytic systems.