Correlation between Electronic Descriptor and Proton-Coupled Electron Transfer Thermodynamics in Doped...

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Graphite-conjugated catalysts (GCCs) link electronic structure to reactivity in single-site heterogeneous catalysts.
• Proton-coupled electron transfer (PCET) in GCC-phenazine involves protonation and electron addition at nitrogen atoms.
• Defects, like heteroatom dopants, can influence catalytic properties.

Purpose of the Study:

• Investigate the impact of graphitic surface defects on the PCET reaction in GCC-phenazine.
• Identify electronic structure descriptors for predicting PCET thermodynamics.
• Develop a more efficient method for calculating redox potentials.

Main Methods:

• Density functional theory (DFT) calculations using a constant potential periodic strategy.
• Computation of proton-coupled redox potentials (E_PCET).
• Identification and analysis of electronic states involved in PCET.

Main Results:

• The electronic states involved in PCET for GCC-phenazine share nitrogen orbital character with molecular phenazine.
• The energy of the phenazine-related lowest unoccupied electronic state (ε_LUS) was identified as a descriptor for PCET thermodynamics.
• ε_LUS, derived from a single DFT calculation, accurately predicts E_PCET, which typically requires numerous calculations.

Conclusions:

• ε_LUS serves as an effective descriptor for PCET thermodynamics in GCC-phenazine, simplifying computational predictions.
• The findings highlight the potential of electronic state energies as descriptors for other single-site catalysts.
• This approach offers a more efficient pathway for understanding and designing catalysts with tailored reactivity.