CO2 reduction to CH4: Harnessing Fe1@B12N12 as single atom catalyst for environment restoration

Abstract

The increased emissions of CO₂ in recent years have been a leading cause of the global warming crisis. Nowadays, carbon conversion technologies represent a potential solution to convert CO₂ into valuable products, instead of emitting it into the atmosphere. This study introduces the iron-doped boron nitride nanocage (Fe₁@B₁₂N₁₂) as a novel single-atom catalyst (SAC) for the electrochemical reduction of CO₂. Utilizing the density functional theory (DFT) calculations, herein we explored the stability, conductivity, and catalytic pathways of Fe₁@B₁₂N₁₂ complex toward the CO₂ reduction to CH₄. The system demonstrates a robust interaction between Fe and the B₁₂N₁₂ nanocage, having strong interaction energy of -1.34 eV, ensuring high stability and effective dispersion of Fe on B₁₂N₁₂. The incorporation of Fe significantly enhances the electrical conductivity of the nanocage by reducing the energy gap from a value of 6.86 eV for the pristine nanocage to a value of 4.20 eV for the doped structure. This reduction in the energy gap facilitates the electron transfer during the carbon reduction reaction (CRR). The analysis of the catalytic pathways reveals that the designed SAC can convert CO₂ into valuable products like CH₄ and H₂O.The associated overpotentials for the CRR are 1.00 V for the COOH pathway and 0.92 V for the HCOO pathway. The results of this study represent Fe₁@B₁₂N₁₂ as an active, noble-metal-free SAC for the CRR. This study offers a sustainable solution to convert CO₂ into valuable products, which mitigates greenhouse gas emissions.