Implementing the Blowers-Masel Approximation to Scale Activation Energy Based on Reaction Enthalpy in Mean-Field...

Area of Science:

• Computational Chemistry and Materials Science
• Chemical Engineering and Catalysis

Background:

• Mean-field microkinetic modeling is crucial for catalyst design and process simulation.
• Adjusting reaction enthalpies in microkinetic models is common for catalyst tuning and data fitting.
• Altering enthalpies necessitates corresponding changes in activation energies for realistic reaction rates.

Purpose of the Study:

• To validate the Blowers-Masel approximation (BMA) for modeling surface reaction kinetics.
• To integrate BMA rate descriptions into Cantera for enhanced catalyst screening workflows.
• To assess the impact of BMA-corrected rates on catalyst performance predictions.

Main Methods:

• Applied the Blowers-Masel approximation (BMA), relating reaction barriers to enthalpies with minimal parameters.
• Validated BMA against literature density functional theory (DFT) data for surface reactions.
• Incorporated BMA kinetics into the open-source Cantera software for process simulations.
• Conducted a catalyst screening for methane partial oxidation on 81 hypothetical metals.

Main Results:

• BMA integration into Cantera enables rapid catalyst screening using linear scaling relationships and BMA kinetics.
• Comparison of BMA-corrected rates versus standard Arrhenius rates (constant activation energies) altered predictions of the most active metals.
• Heat maps revealed that BMA-adjusted rates changed the most influential species in sensitivity analyses, though not the most sensitive reactions.

Conclusions:

• The Blowers-Masel approximation provides a data-efficient method for adjusting activation energies in microkinetic models.
• The developed Cantera workflow facilitates efficient catalyst screening by incorporating BMA kinetics.
• Using BMA-corrected rates significantly impacts the identification of optimal catalysts and understanding of reaction mechanisms.