N-Doped CrS₂ Monolayer as a Highly-Efficient Catalyst for Oxygen Reduction Reaction: A Computational Study

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Developing cost-effective and efficient catalysts for the oxygen reduction reaction (ORR) is essential for widespread fuel cell adoption.
• Current catalysts, like platinum, are expensive, driving the search for alternatives.

Purpose of the Study:

• To computationally screen non-metal doped CrS2 monolayers (X@CrS2) as potential ORR catalysts.
• To identify the most promising dopant for enhancing ORR activity and stability.

Main Methods:

• Density Functional Theory (DFT) computations were employed to investigate the electronic structure and catalytic properties.
• Formation energies, binding energies, and free energy profiles for ORR were calculated.
• Linear scaling relationships and volcano plots were analyzed to understand catalytic mechanisms.

Main Results:

• Most doped CrS2 monolayers exhibited high stability, indicated by negative formation energies and large binding energies.
• Nitrogen-doped CrS2 (N@CrS2) demonstrated the highest ORR catalytic activity with the lowest overpotential (0.41 V).
• The superior performance of N@CrS2 is attributed to optimal binding with oxygenated intermediates, confirmed by p-band center and charge transfer analysis.

Conclusions:

• Non-metal doping of CrS2 monolayers is a viable strategy for designing efficient ORR electrocatalysts.
• N@CrS2 emerges as a promising low-cost alternative to platinum for fuel cell applications.
• This work offers a new avenue for developing advanced electrocatalysts through targeted doping.