First Principles Calculations Combining Microkinetic Model for MXene Supported Single Atom Catalysts Screening and...

Area of Science:

• Computational materials science
• Electrocatalysis
• Surface chemistry

Background:

• Single-atom catalysts (SACs) are crucial for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR).
• Understanding intermediate adsorption dynamics is vital for accurate catalyst mechanism elucidation.
• MXene-supported single atoms, specifically W2CO2, are promising candidates for electrocatalysis.

Purpose of the Study:

• To investigate the effect of dynamic co-adsorption of intermediates on SACs for OER and ORR.
• To screen single atoms supported on W2CO2 (M1-W2CO2) considering dynamic adsorption effects.
• To provide guidance for designing efficient single-atom electrocatalysts.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Microkinetic simulations were utilized to model reaction mechanisms.
• Screening of single atoms on oxygen vacancy sites of W2CO2 (M1-W2CO2(Ov)) was performed.

Main Results:

• Static adsorption models identified only Pt1-W2CO2(Ov) for OER and Au1-W2CO2(Ov) for ORR.
• Dynamic adsorption screening identified additional SACs: Pt1(Rh1, Ni1)-W2CO2(Ov) for OER and Pt1(Ag1, Au1)-W2CO2(Ov) for ORR.
• Intermediate adsorption shifts binding energies (ΔG*OH) towards optimal volcano plot regions, altering predicted catalyst performance.

Conclusions:

• Dynamic co-adsorption significantly influences the predicted performance of single-atom catalysts.
• The inclusion of dynamic adsorption reveals a broader range of promising OER and ORR SACs.
• This study underscores the importance of dynamic adsorption in theoretical screening for catalyst design.