Electrocatalytic CO₂ Reduction Empowered by 2D Hexagonal Transition Metal Borides

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalysis for carbon dioxide reduction reaction (CO2RR) is crucial for sustainability.
• Conventional transition metal electrocatalysts suffer from high overpotentials.
• 2D hexagonal transition metal borides (h-MBenes) are emerging as promising electrocatalysts.

Purpose of the Study:

• To theoretically investigate the CO2RR catalytic properties of pristine h-MBenes and their O- and OH-terminated counterparts.
• To explore the potential of h-MBenes for efficient CO2RR applications.
• To understand the role of termination groups in tuning catalytic performance.

Main Methods:

• First-principles theoretical calculations.
• Investigated pristine h-MBenes (h-MB), O-terminated (h-MBO), and OH-terminated (h-MBOH) structures.
• Focused on transition metals Sc, Ti, V, Zr, Nb, Hf, and Ta.

Main Results:

• Pristine h-MB and h-MBO showed poor CO2RR performance due to suboptimal CO2 interactions.
• h-MBOH structures demonstrated significant promise for CO2RR.
• ScBOH, TiBOH, and ZrBOH exhibited exceptionally low limiting potentials (-0.46, -0.53, and -0.64 V, respectively).

Conclusions:

• The hydroxyl group (-OH) plays a critical role in optimizing h-MBene electronic properties for CO2RR.
• Optimized intermediate adsorption prevents excessive binding and enhances catalytic efficiency.
• h-MBOHs are highly promising electrocatalysts for efficient CO2RR, advancing carbon neutrality goals.