First-Principles Study on the CO₂ Reduction Reaction (CO₂RR) Performance of h-BN-Based Single-Atom Catalysts Modified...

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Designing efficient single-atom catalysts (SACs) is crucial for electrochemical CO2 reduction reaction (CO2RR).
• Defect-engineered hexagonal boron nitride (h-BN) offers a promising support for SACs.
• Understanding reaction mechanisms and selectivity is vital for catalyst design.

Purpose of the Study:

• To explore transition metal (TM) doped h-BN SACs with vacancies for CO2RR and hydrogen evolution reaction (HER).
• To investigate the catalytic performance and selectivity of TM@B-1N and TM@BN-1 systems.
• To provide theoretical insights for designing bifunctional SACs.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Systematic exploration of various transition metals (Mn, Fe, Co, Ni, Cu, Zn) doped into B or N vacancies in h-BN.
• Integrated Crystal Orbital Hamiltonian Population (ICOHP) analysis was used to understand electronic structure and bonding.

Main Results:

• DFT calculations revealed that TM@B-1N and TM@BN-1 SACs can weaken CO2 sp orbital hybridization, lowering reaction barriers.
• Mn@B-1N exhibited the lowest limiting potential (-0.524 V) for CO2RR, showing excellent catalytic activity.
• Co@BN-1 demonstrated the highest activity for HER (-0.217 V).
• Mn@B-1N showed significantly higher selectivity for CO2RR over HER (16.4 times).

Conclusions:

• Mn@B-1N and Co@BN-1 SACs are promising candidates for selective CO2 conversion and efficient hydrogen production, respectively.
• The study provides a theoretical framework for designing bifunctional SACs with tunable reaction pathways.
• Defect engineering in h-BN is an effective strategy for developing high-performance SACs.