Role of Active Centers in Predicting the Catalyst Turnover: A Theoretical Study

Area of Science:

• Catalysis
• Sustainable Energy
• Computational Chemistry

Background:

• Water oxidation catalysis is crucial for sustainable energy conversion.
• Iron, manganese, cobalt, and nickel complexes with Pytacn ligands have been studied for water oxidation.
• The specific role of active metal centers in catalytic performance remains underexplored.

Purpose of the Study:

• To computationally assess the role of active metal centers in [M(OTf)2(Pytacn)] complexes for water oxidation.
• To utilize the newly developed efficiency conceptualization model (ECM) and MaxKinEff framework for catalytic performance evaluation.

Main Methods:

• Computational analysis using the efficiency conceptualization model (ECM).
• Application of the maximum kinetic efficiency (MaxKinEff) framework.
• Comparative assessment of various [M(OTf)2(Pytacn)] complexes (M=Mn, Co, Ni).

Main Results:

• Cobalt-based [Co(OTf)2(Pytacn)] is identified as a superior catalyst for water oxidation.
• Cobalt catalysts demonstrate a longer operational lifespan (approx. 44 days) and higher turnover numbers (TON).
• Computed catalytic efficiency values: ECM = 3.30 h⁻¹, TON(ECM) = 3456; MaxKinEff = 12.43 h⁻¹, TON(MaxKinEff) = 3616.

Conclusions:

• Cobalt active centers significantly enhance the catalytic performance of [M(OTf)2(Pytacn)] complexes for water oxidation.
• The study provides a computational framework for evaluating and optimizing molecular water oxidation catalysts.
• Cobalt-based catalysts represent a promising avenue for developing efficient molecular catalysts for sustainable energy applications.