Screening Transition-Metal-Incorporated β-AgVO₃ for Augmented Oxygen Reduction Activity

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Platinum-based catalysts are essential for fuel cells but costly.
• Silver vanadate (AgVO3) is known for photocatalysis but its electrocatalytic potential is unexplored.
• Developing cost-effective oxygen reduction reaction (ORR) catalysts is vital for green energy technologies.

Purpose of the Study:

• To investigate the electrocatalytic ORR activity of β-AgVO3 using computational modeling.
• To explore the effect of single transition metal atom incorporation on β-AgVO3's ORR performance.
• To identify optimal transition metal dopants for enhanced ORR activity in AgVO3-based catalysts.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to model the ORR process on β-AgVO3.
• The free energy changes of ORR intermediates (*OOH, *OH, *O) were analyzed for various transition metal dopants.
• Electronic structure analysis was performed to correlate catalytic activity with electronic properties.

Main Results:

• Pristine β-AgVO3 shows weak ORR catalytic activity, with vanadium as the preferred active site.
• Incorporating single transition metal atoms significantly modifies ORR activity, lowering the overpotential.
• Cobalt-incorporated β-AgVO3 demonstrated the highest ORR activity due to optimal binding of intermediates.
• Electronic structure analysis revealed a correlation between optimal activity and the emergence of midgap states.

Conclusions:

• Single transition metal atom doping, especially with cobalt, can substantially enhance the ORR activity of β-AgVO3.
• This approach offers a promising strategy for developing novel, cost-effective ORR electrocatalysts for fuel cells.
• Minimal loading of transition metals on stable oxides like AgVO3 can lead to highly active ORR catalysts.